Demultiplexer and communication device

The present invention relates to a demultiplexer having a plurality of filters having different pass frequency bands and a communication device including the demultiplexer.

Filters used in portable communication terminal devices are required to be smaller and lighter, and have the characteristics of low loss in the passing frequency band and large attenuation outside the passing frequency band. However, it is required that the change in frequency characteristics from the passing frequency band to the outside of the passing frequency band is steep.

Further, the demultiplexer that separates the signal in the transmission frequency band and the signal in the reception side frequency band is also required to be compact and lightweight. In the transmission filter used for the demultiplexer, the loss is low in the transmission frequency band, the attenuation is high in the reception frequency band, and the frequency characteristic changes sharply from the transmission frequency band to the reception frequency band. It has been demanded. In the reception filter used for the demultiplexer, the loss is low in the reception frequency band, the attenuation is high in the transmission frequency band, and the frequency characteristics change sharply from the reception frequency band to the transmission side frequency band. Is required. Further, the demultiplexer is required to have good isolation characteristics from the transmitting terminal to the receiving terminal.

Conventionally, as a demultiplexer, one equipped with a dielectric resonator filter has been used, but due to a request for miniaturization, a demultiplexer and a piezoelectric thin film equipped with a surface acoustic wave (abbreviation: SAW) filter. Demultiplexers equipped with a Film Bulk Acoustic Resonator (abbreviation: FBAR) filter have come to be used.

As a demultiplexer provided with a conventional SAW filter, as shown in Japanese Patent Application Laid-Open No. 2002-176337, between the transmission filter and the reception filter in order to match the transmission filter and the reception filter. As a matching circuit, a strip line, a distributed constant line, and chip components such as a chip inductor and a chip capacitor are arranged. In JP-A-2002-176337, since the matching circuit is arranged side by side with the transmission filter and the reception filter, it is not sufficiently miniaturized.

In Japanese Unexamined Patent Publication No. 2004-336181, a SAW device having an excitation electrode provided on a piezoelectric substrate is mounted in a recess of the package body, and the electrode pattern on the piezoelectric substrate is connected to the terminal portion of the package by wire bonding technology. After that, the SAW filter is manufactured by airtightly sealing the concave portion with a cap or the like, and the size is reduced by incorporating a matching circuit in the package body.

In this case, by connecting the parallel arms forming the SAW device and the terminal part of the package with a bonding wire, the inductance component of the bonding wire is effectively used to improve the attenuation characteristics outside the pass frequency band of the SAW filter. It is possible to do.

In order to further reduce the size of the package, wire is actively utilized by chip size package (abbreviation: CSP) technology, and SAW devices formed on the substrate are flip-chip mounted on the circuit board. It has also been proposed to reduce the space and height required for bonding. In the case of flip-chip mounting, since the inductance component composed of the bonding wire is eliminated, it is possible to improve the attenuation characteristics outside the passing frequency band by providing a line having an inductance component on the circuit board. In Japanese Patent Application Laid-Open No. 2003-198325, lines having a matching circuit and an inductance component are arranged in the package body so that the circuits do not interfere with each other. Specifically, a matching circuit is formed in the inner layer of the package, a line having an inductance component is routed at a place away from the matching circuit, and is connected to the ground by casting on the outer circumference of the package. Further, in order to suppress the interference between the matching circuit and other circuits, a ground layer is arranged on the upper layer of the matching circuit. For this reason, it has not been sufficiently reduced in height and size.

FIG. 11 is a diagram showing the configuration of the demultiplexer 1 of the conventional technique. The demultiplexer 1 includes a first filter 2 and a second filter 3 having different pass frequency bands. The first filter 2 and the second filter 3 are connected to the common connection point P, and the antenna terminal 4 is connected to the common connection point P. For example, the first filter 2 is a filter that passes through the transmission frequency band (hereinafter referred to as "Tx filter 2"), and the second filter 3 is a filter that passes through the reception frequency band (hereinafter referred to as "Rx filter 3"). At one time, the transmission signal given to the transmission signal terminal 5 from the transmission circuit (not shown) passes through the Tx filter 2 and is given to the antenna (not shown) from the antenna terminal 4 and transmitted to another communication device. Further, the received signal received by the antenna and input to the antenna terminal 4 passes through the Rx filter 3 and is given from the received signal terminal 6 to a receiving circuit (not shown).

In the demultiplexer 1, for example, a part of the transmission signal given from the transmission circuit to the transmission signal terminal 5 passes through the Tx filter 2 and leaks from the common connection point P to the Rx filter 3. Therefore, a matching circuit 7 is provided between the antenna terminal 4 and the filters 2 and 3, and more specifically, between the antenna terminal 4 and the common connection point P. By the matching circuit 7, the impedance of the transmitting circuit seen from the antenna terminal 4 becomes almost infinite in the receiving frequency band, and the impedance of the receiving circuit seen from the transmitting circuit becomes almost infinite in the transmitting frequency band. can do.

In the conventional technique, in order to reduce the size of the SAW filter and maintain good attenuation characteristics outside the passing frequency band, wires and lines having an inductance component are provided between the parallel arms forming the SAW device and the ground. The method is used. The above-mentioned method is also used in the duplexer to improve the attenuation characteristic and the isolation characteristic outside the passing frequency band, but the duplexer manufactured by using the CSP technique uses the wire bonding technique. Since it is not possible to use a bonding wire having an inductance component, unlike the demultiplexer manufactured in the above, it is necessary to provide a line having an inductance component on the circuit board.

However, since the input / output electrode, the ground electrode, and the matching circuit are arranged on the circuit board constituting the demultiplexer, it is difficult to provide a line having a sufficient length having an inductance component, and desired attenuation is achieved. There is a problem that the characteristics and the isolation characteristics cannot be satisfied.

An object of the present invention is a demultiplexer capable of improving attenuation characteristics and isolation characteristics outside the passing frequency band on the high frequency side of a filter having a lower passing frequency band among two filters having different passing frequency bands. It is to provide a communication device.

The present invention includes a first signal input unit, a first signal output unit, and a first ground unit connected to a parallel arm including at least one of a resonator and a capacitor, and a predetermined passage. The first filter with a frequency band and A second filter having a second signal input section, a second signal output section, and a second ground section and having a pass frequency band higher than the pass frequency band of the first filter. A common terminal to which the first signal output unit and the second signal input unit are connected, The first wiring connected to the first signal output unit and the second signal input unit, and The second wiring connected to the first ground portion and Including the first and second wirings, and a ground terminal connected to the second ground portion and to which a ground potential is applied, respectively. One of the angles formed by the extending direction of a part of the first wiring and the extending direction of a part of the second wiring on a virtual plane predetermined is selected to be less than 90 degrees, and the above-mentioned The first and second wirings are formed so that the direction of the current flowing through the part of the first wiring and the direction of the current flowing through the part of the second wiring are opposite to each other.<u style="single">、</u><u style="single">No other wiring is formed between the part of the first wiring and the part of the second wiring.</u>It is a demultiplexer characterized by this.

Further, the present invention further includes a multilayer wiring board provided with the first filter, the second filter, the common terminal, the first wiring, the second wiring and the ground terminal. The part of the first wiring and the part of the second wiring are formed in the same layer of the multilayer wiring board.

Further, the present invention<u style="single">Further including a multilayer wiring board provided with the first filter, the second filter, the common terminal, the first wiring, the second wiring, and the ground terminal.</u> The part of the first wiring and the part of the second wiring are demultiplexers characterized in that they are formed in different layers of the multilayer wiring board.

Further, the present invention includes the above-mentioned demultiplexer and The antenna connected to the common terminal and The communication device is characterized by including a transmission / reception processing unit that supplies a signal to the first signal input unit and receives a signal from the second signal output unit.

According to the present invention, the first filter is a first ground section connected to a parallel arm including a first signal input section, a first signal output section, and at least one of a resonator and a capacitor. And has a predetermined passing frequency band. The second filter includes a second signal input section, a second signal output section, and a second ground section, and has a pass frequency band higher than the pass frequency band of the first filter. The first signal output unit and the second signal input unit are connected to a common terminal. The first wiring is connected to the first signal output unit and the second signal input unit, and the second wiring is connected to the first ground unit. A ground terminal is connected to the first and second wirings and the second ground portion, respectively, and a ground potential is given.

In the first wiring and the second wiring, one of the angles formed by the extending direction of a part of the first wiring and the extending direction of a part of the second wiring on a virtual one plane is less than 90 degrees. The direction of the current flowing through the part of the first wiring is opposite to the direction of the current flowing through the part of the second wiring. Here, the direction of the current flowing through the part of the first wiring and the direction of the current flowing through the part of the second wiring are opposite to each other, that is, the part of the first wiring and the second part. It means that the directions of the magnetic fluxes surrounding the above-mentioned part of the wiring are opposite to each other.<u style="single">No other wiring is formed between the part of the first wiring and the part of the second wiring.</u>

When the part of the first wiring and the part of the second wiring are brought close to each other, the mutual induction coupling becomes large, and the direction of the current flowing through the part of the first wiring and the direction of the current flowing through the part of the first wiring and the said of the second wiring. Since the directions of the currents flowing through the part are opposite, in other words, the directions of the magnetic fluxes surrounding the part of the first wiring and the part of the second wiring are opposite, the magnetic fluxes cancel each other out. The inductance of the second wiring is apparently small.

The mutual inductance formed by at least one of the resonator and the capacitor constituting the parallel arm of the first filter, the part of the first wiring and the part of the second wiring, and the second wiring. A series resonant circuit is formed by the inductance of. When the mutual inductance formed by the part of the first wiring and the part of the second wiring becomes large, the mutual induction coupling becomes large, and the direction of the current flowing through the part of the first wiring and the said. Since the direction of the current flowing through the part of the second wiring is opposite, the resonance frequency of the series resonant circuit increases.

By forming the first wiring and the second wiring as described above, the series resonance circuit can be resonated outside the predetermined passing frequency band on the high frequency side of the first filter, and the attenuation pole can be relatively easily set. Can be provided. As a result, the amount of attenuation outside the passing frequency band on the high frequency side of the first filter can be increased, and the attenuation characteristics can be improved. Further, since the amount of attenuation outside the passing frequency band on the high frequency side of the first filter can be increased, the isolation characteristics outside the passing frequency band on the high frequency side of the first filter can be improved.<u style="single">Further, since no other wiring is formed between the part of the first wiring and the part of the second wiring, it surrounds a part of the first wiring and a part of the second wiring, respectively. The magnetic fluxes affect each other, and a part of the first wiring and a part of the second wiring can be well electromagnetically coupled.</u>

According to the present invention, the first filter, the second filter, the common terminal, the first wiring, the second wiring, and the ground terminal are provided on the multilayer wiring board. The part of the first wiring and the part of the second wiring are formed on the same layer of the multilayer wiring board. Therefore, the number of layers can be reduced as compared with the case where the part of the first wiring and the part of the second wiring are formed in different layers of the multilayer wiring board, and the thickness of the multilayer wiring board can be reduced. It is possible to reduce the size in the direction.

According to the present invention<u style="single">The first filter, the second filter, the common terminal, the first wiring, the second wiring, and the ground terminal are provided on the multilayer wiring board.</u>The part of the first wiring and the part of the second wiring are formed in different layers of the multilayer wiring board. As a result, as compared with the case where the part of the first wiring and the part of the second wiring are formed on the same layer of the multilayer wiring board, the part of the first wiring and the part of the second wiring The area of one surface portion of the layer in which the part is formed and orthogonal to the thickness direction of the multilayer wiring board can be reduced. As a result, it is possible to reduce the size of the multilayer wiring board in the direction orthogonal to the thickness direction.

According to the present invention, the antenna is connected to the common terminal. The transmission / reception processing unit transmits a signal to another communication device via an antenna connected to a common terminal by giving a signal to the first signal input unit of the demultiplexer. Further, the transmission / reception processing unit receives a signal transmitted from another communication device by receiving a signal given from the second signal output unit of the demultiplexer. In the communication device, the attenuation characteristic outside the passing frequency band on the high frequency side of the first filter can be improved, and the isolation characteristic outside the passing frequency band on the high frequency side of the first filter can be improved. Since the device is provided, it is possible to realize a communication device capable of transmitting and receiving a signal having excellent quality without transmitting or receiving an unnecessary signal outside the passing frequency band.

Objectives, features, and advantages of the present invention will become clearer from the detailed description and drawings below.

<figref num="1">It is a figure which shows the structure of the demultiplexer 10 which is 1st Embodiment of this invention.</figref><figref num="2">It is a figure which shows the structure of the 1st and 2nd filters 11 and 12.</figref><figref num="3">It is sectional drawing which shows typically the mounting board 35.</figref><figref num="4">(A) to (G) are diagrams showing the wiring structure of the mounting board 35.</figref><figref num="5">It is a block diagram which shows the structure of the communication apparatus 100 which is one Embodiment of this invention.</figref><figref num="6">(A) to (G) are diagrams showing the wiring structure of the mounting board 90.</figref><figref num="7">It is sectional drawing which shows the wiring structure of the 2nd and 3rd wiring formation layers 37, 38 seen from the cut plane line BB of FIG.</figref><figref num="8">It is a figure which shows typically the SAW element 200.</figref><figref num="9">It is a graph which shows the measurement result of the attenuation characteristic and isolation characteristic of an Example.</figref><figref num="10">It is a graph which shows the measurement result of the attenuation characteristic and the isolation characteristic of the comparative example.</figref><figref num="11">It is a figure which shows the structure of the demultiplexer 1 of the prior art.</figref>

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a demultiplexer 10 according to a first embodiment of the present invention. FIG. 2 is a diagram showing the configurations of the first and second filters 11 and 12. The demultiplexer 10 is provided between an antenna (not shown) and a transmission / reception processing unit (not shown). The demultiplexer 10 includes the first filter 11, the second filter 12, the common terminal 13, the ground terminal 14, the transmission signal terminal 15, the reception signal terminal 16, the first wiring 17, the second wiring 18, the third wiring 19, and the first. It is composed of 4 wiring 20, 5th wiring 21, 6th wiring 22 and ground wiring 23.

The first filter 11 includes a first signal input unit 25, a first signal output unit 26, and a first ground unit 27. The second filter 12 includes a second signal input unit 30, a second signal output unit 31, and a second ground unit 32. The first and second filters 11 and 12 of the present embodiment are configured by a ladder type filter as shown in FIG. In the ladder type filter, a plurality of filter constituent elements are connected alternately in series and in parallel. The basic section II of the ladder type filter is composed of a first filter component F1 forming a series arm and a second filter component F2 forming a parallel arm. In the first and second filters 11 and 12 of the present embodiment, the first and second filter constituent elements F1 and F2 are surface acoustic waves (Surface Acoustic). Wave; Abbreviation: SAW) Realized by a SAW filter composed of resonators. The first and second filters 11 and 12 may be realized by a filter in which the first filter component F1 is composed of a SAW resonator and the second filter component F2 is composed of a capacitor. Further, a line having an inductance element or an inductance component may be connected in series or in parallel with the second filter constituent element F2.

In the present embodiment, the first filter 11 is used as a transmission filter having a predetermined pass frequency band, specifically, a pass frequency band of 824 MHz to 849 MHz, and the second filter 12 is the pass frequency of the first filter 11. It is used as a reception filter having a pass frequency band higher than the band, specifically, a pass frequency band of 869 MHz to 894 MHz. In the following description, the first filter 11 may be referred to as a transmission filter 11 and the second filter 12 may be referred to as a reception filter 12.

The first signal output unit 26 and the second signal input unit 30 are connected to the common connection point CP, and the common terminal 13 which is an antenna terminal is connected to the common connection point CP. The first wiring 17 is connected to the common terminal 13, the first signal output unit 26, and the second signal input unit 30. A matching circuit is formed in a part of the first wiring 17 to reduce the interference between the transmission filter 11 and the reception filter 12 and obtain desired filter characteristics. The second wiring 18 is connected to the first ground portion 27. A ground terminal 14 is connected to the first and second wirings 17, 18 and the second ground portion 32, respectively, and a ground potential is given.

The first wiring 17 and the second wiring 18 are one of the angles formed by the extending direction of a part L1 of the first wiring and the extending direction of a part L2 of the second wiring on a predetermined virtual plane. The angle is selected to be less than 90 degrees, and the direction I1 of the current flowing through a part L1 of the first wiring and the direction I2 of the current flowing through a part L2 of the second wiring are formed to be opposite to each other. In FIG. 1, the angle formed by the extending direction of a part L1 of the first wiring and the extending direction of a part L2 of the second wiring on a virtual plane defined in advance is 0 degrees, that is, a part of the first wiring. The case where the extending direction of L1 and the extending direction of a part of the second wiring L2 are the same is shown. In the present embodiment, by providing the first wiring 17 and the second wiring 18 as described above, a part L1 of the first wiring and a part L2 of the second wiring are electromagnetically coupled.

Here, the direction I1 of the current flowing through the part L1 of the first wiring and the direction I2 of the current flowing through the part L2 of the second wiring are opposite to each other. It means that the directions of the magnetic fluxes surrounding some L2 are opposite. If the directions of the magnetic fluxes surrounding a part L1 of the first wiring and a part L2 of the second wiring are opposite to each other, the magnetic fluxes cancel each other out, so that the inductance of the second wiring 18 becomes apparently small.

Further, an electrode other than the electrode forming the first wiring 17 and the second wiring 18 is not arranged between a part L1 of the first wiring and a part L2 of the second wiring. Further, it is configured so that a part L1 of the first wiring and a part L2 of the second wiring form an opposing portion adjacent to each other on a predetermined virtual plane. As a result, the magnetic flux surrounding a part L1 of the first wiring and a part L2 of the second wiring influence each other, and a part L1 of the first wiring and a part L2 of the second wiring are satisfactorily electromagnetic. It is possible to combine the two.

A part L1 of the first wiring is selected so that the width dimension is, for example, 50 μm or more and less than 150 μm, and the wiring length is, for example, 0.3 mm or more and less than 2 mm. A part of the second wiring L2 is selected so that the width dimension is, for example, 50 μm or more and less than 150 μm, and the wiring length is, for example, 0.2 mm or more and less than 1.5 mm. The coupling coefficient between a part L1 of the first wiring and a part L2 of the second wiring is selected to be, for example, 0.4. The coupling coefficient is preferably 0.1 or more and less than 0.6.

The third wiring 19 connects the transmission signal terminal 15 and the first signal input unit 25. The fourth wiring 20 connects the first signal output unit 26 and the common terminal 13. The fifth wiring 21 has a portion that connects the second signal input unit 30 and the common terminal 13 and connects the common terminal 13 and the common connection point CP in common with the fourth wiring 20. The sixth wiring 22 connects the received signal terminal 16 and the second signal output unit 31. The ground wiring 23 connects the second ground portion 32 and the ground terminal 14. A part of the ground wiring 23 is common to the wiring between the part L1 of the first wiring and the ground terminal 14.

The demultiplexer 10 of the present embodiment is formed by flip-chip mounting a filter device including a transmission filter 11 and a reception filter 12 on a mounting substrate 35.

FIG. 3 is a cross-sectional view schematically showing the mounting board 35. 4A to 4G are diagrams showing the wiring structure of the mounting board 35. FIG. 4A is a plan view seen from the thickness direction of the mounting substrate 35, FIG. 4B is a cross-sectional view showing the first wiring cambium 36 seen from the cut plane line AA of FIG. 3, and FIG. 4C is a cross-sectional view of FIG. It is sectional drawing which shows the 2nd wiring formation layer 37 seen from the cut plane line BB, and FIG. 4D is the sectional view which shows the 2nd wiring formation layer 37 seen from the cut plane line CC of FIG. FIG. 4E is a cross-sectional view showing the third wiring forming layer 38 seen from the cutting plane line DD of FIG. 3, and FIG. 4F is a cross-sectional view showing the third wiring forming layer 38 seen from the cutting plane line EE of FIG. 4G is a bottom view showing the mounting board 35.

The mounting board 35 is a multi-layer wiring board having a multi-layer structure in which three layers are laminated, and is realized by, for example, a low temperature co-fired ceramics (abbreviation: LTCC) substrate. Alumina is used as the main raw material of LTCC, and the relative permittivity is about 6 or more and less than 18. Further, the mounting substrate 35 may be realized by a resin substrate using a resin material such as a glass epoxy resin, an epoxy resin or a polyimide resin, and the relative permittivity of the resin material is about 3 or more and less than 8. The mounting board 35 includes a first wiring forming layer 36, a second wiring forming layer 37, and a third wiring forming layer 38. In the mounting board 35, the first to third wiring forming layers 36 to 38 are laminated in the order of the third wiring forming layer 38, the second wiring forming layer 37, and the first wiring forming layer 36.

The first to third wiring forming layers 36 to 38 are formed in a rectangular shape projected onto a virtual plane perpendicular to the thickness direction thereof. In the following description, the two longitudinal ends of the first to third wiring cambium 36 to 38 are referred to as the first end and the second end, respectively, and the first to third wiring cambium 36 to 38 The two sides in the width direction are called the first side and the second side, respectively, and the two surfaces in the thickness direction of the first to third wiring cambium 36 to 38 are the first surface and the second surface, respectively. It's called a club. On the first surface portion of the first to third wiring forming layers 36 to 38, a plurality of the first and second wirings 17 and 18 described above, and the third to sixth wirings 19 to 22 and the ground wiring 23 described later are formed. Wiring part is formed. Further, a plurality of vias penetrating each wiring forming layer are formed in the first to third wiring forming layers 36 to 38. Further, a common terminal 13, a ground terminal 14, a transmission signal terminal 15, and a reception signal terminal 16 are formed on the bottom surface of the mounting board 35.

The first wiring 17 orbits counterclockwise around a position closer to the first side portion than the central portion in the longitudinal direction and the central portion in the width direction of the second wiring forming layer 37, and is at the second end portion and in the width direction. The first spiral wiring portion 55 formed so as to extend from the central portion to a position closer to the first side portion, and the third wiring forming layer 38 at the central portion in the longitudinal direction and closer to the first side portion than the central portion in the width direction. A second spiral wiring portion 70 formed by rotating clockwise around the position and extending to a position closer to the first side portion than the central portion in the width direction at the first end portion, and a third wiring forming layer 38. The third ground wiring portion 74 formed in connection with the first and second end portions and the second side portion, the tenth via 65 and the eleventh via 66 penetrating the second wiring forming layer 37, and the third wiring. It includes a third grounding via 79 that penetrates the forming layer 38. The matching circuit formed in a part of the first wiring 17 is composed of the first spiral wiring portion 55, the second spiral wiring portion 70, and the tenth via 65 of the first wiring 17. The end of the first spiral wiring portion 55 formed at the center of the second wiring forming layer 37 in the longitudinal direction and closer to the first side than the central portion in the width direction, and the longitudinal direction of the third wiring forming layer 38. The end portion of the second spiral wiring portion 70 formed at the central portion and at a position closer to the first side portion than the central portion in the width direction is connected via the tenth via 65. The first wiring 17 is connected to the third grounded wiring portion 74 via the eleventh via 66 penetrating the second wiring forming layer 37.

The second wiring 18 has a first wiring portion 40 formed closer to the first end portion than the central portion in the longitudinal direction of the first wiring forming layer 36 and in the central portion in the width direction, and the width direction of the second wiring forming layer 37. A sixth wiring portion 56 formed near the center and closer to the first end than the central portion in the longitudinal direction so as to extend substantially in the longitudinal direction, and a central portion in the longitudinal direction of the third wiring forming layer 38. The tenth wiring portion 71 formed at a position closer to the second end portion and closer to the second side portion than the central portion in the width direction, the first via 46 penetrating the first wiring forming layer 36, and the first 2 The sixth via 61 penetrating the wiring forming layer 37 and the twelfth via 75 penetrating the third wiring forming layer 38 are included. The first wiring portion 40 and the first end portion of the sixth wiring portion 56 in the extending direction are connected via the first via 46. The second end portion of the sixth wiring portion 56 in the extending direction and the tenth wiring portion 71 are connected via the sixth via 61. The second wiring 18 is formed on the ground terminal 14 formed at the center of the bottom surface of the mounting board 35 in the longitudinal direction and on the first side, and on the first and second ends and excluding the second side. Be connected.

The third wiring 19 includes a second wiring portion 41 formed at a position closer to the first end portion than the central portion in the longitudinal direction and closer to the second side portion than the central portion in the width direction of the first wiring forming layer 36. The seventh wiring portion 57 and the third wiring forming layer 38 formed at a position closer to the first end portion than the central portion in the longitudinal direction and closer to the second side portion than the central portion in the width direction of the second wiring forming layer 37. The eleventh wiring portion 72 formed at a position closer to the first end portion than the central portion in the longitudinal direction and closer to the second side portion than the central portion in the width direction, and the second via penetrating the first wiring forming layer 36. It is composed of 47, an eighth via 63 penetrating the second wiring forming layer 37, and a thirteenth via 76 penetrating the third wiring forming layer 38.

The fourth wiring 20 includes a third wiring portion 42 formed at a position closer to the first end portion than the central portion in the longitudinal direction and closer to the first side portion than the central portion in the width direction of the first wiring forming layer 36. The eighth wiring portion 58 formed in the central portion in the longitudinal direction and the first side portion of the second wiring forming layer 37, the second spiral wiring portion 70 formed in the third wiring forming layer 38, and the first wiring forming. It is composed of a third via 48 penetrating the layer 36, a seventh via 62 penetrating the second wiring forming layer 37, and a 14th via 77 penetrating the third wiring forming layer 38.

The fifth wiring 21 includes a fourth wiring portion 43 formed at a position closer to the second end portion than the central portion in the longitudinal direction and closer to the first side portion than the central portion in the width direction of the first wiring forming layer 36. The eighth wiring portion 58 formed in the second wiring forming layer 37, the second spiral wiring portion 70 formed in the third wiring forming layer 38, and the fourth via 49 penetrating the first wiring forming layer 36. It is composed of a seventh via 62 penetrating the second wiring forming layer 37 and a 14th via 77 penetrating the third wiring forming layer 38.

The sixth wiring 22 includes a fifth wiring portion 44 formed at a position closer to the second end portion than the central portion in the longitudinal direction and closer to the second side portion than the central portion in the width direction of the first wiring forming layer 36. The ninth wiring portion 59 and the third wiring forming layer 38 formed at a position closer to the second end portion than the central portion in the longitudinal direction and closer to the second side portion than the central portion in the width direction of the second wiring forming layer 37. The twelfth wiring portion 73 formed at a position closer to the second end portion than the central portion in the longitudinal direction and closer to the second side portion than the central portion in the width direction, and the fifth via penetrating the first wiring forming layer 36. It is composed of 50, a ninth via 64 penetrating the second wiring forming layer 37, and a fifteenth via 78 penetrating the third wiring forming layer 38.

The ground wiring 23 includes a first ground wiring portion 45 formed over the entire circumference of the first wiring forming layer 36 when viewed from the thickness direction of the first wiring forming layer 36, and the first and second ends and the second side of the second wiring forming layer 37. The second ground wiring portion 60 formed in the portion, the third ground wiring portion 74 formed in the third wiring forming layer 38, the first ground via 51 penetrating the first wiring forming layer 36, and the second It is composed of a second grounding via 67 penetrating the wiring forming layer 37 and a third grounding via 79 penetrating the third wiring forming layer 38.

Transmission input to the transmission signal terminal 15 formed on the first end of the two longitudinal ends of the bottom surface of the mounting board 35 and on the second side of the two widthwise sides. The signal passes through the third wiring 19 and is input to the first signal input unit 25 of the transmission filter 11. The signal output from the first signal output unit 26 of the transmission filter 11 passes through the fourth wiring 20 and is the first of the two side portions in the longitudinal direction and the width direction on the bottom surface portion of the mounting board 35. It is output from the common terminal 13 formed on one side.

Further, the received signal input to the common terminal 13 passes through the fifth wiring 21 and is input to the second signal input unit 30 of the receiving filter 12. The signal output from the second signal output unit 31 of the reception filter 12 passes through the sixth wiring 22 and is the second end of the two longitudinal ends on the bottom surface of the mounting board 35. It is output from the reception signal terminal 16 formed on the two sides.

In the present embodiment, a part L1 of the first wiring and a part L2 of the second wiring are formed on the same layer of the mounting board 35. Specifically, a part of the first spiral wiring part 55 corresponding to a part L1 of the first wiring and a part of the sixth wiring part 56 corresponding to a part L2 of the second wiring are second. It is formed on the first surface portion of the wiring forming layer 37. Hereinafter, "a part of the first spiral wiring portion 55" will be referred to with a reference reference numeral "L1", and "a part of the sixth wiring portion 56" will be referred to with a reference reference numeral "L2".

Furthermore, in the first surface portion of the second wiring forming layer 37, the angle formed by the extending direction of a part L1 of the first spiral wiring portion 55 and the extending direction of a part L2 of the sixth wiring portion 56 is The direction of the current flowing through a part L1 of the first spiral wiring portion 55 and the direction of the current flowing through a part L2 of the sixth wiring portion 56 are opposite to each other so that the degree is less than 90 degrees and 0 degrees in the present embodiment. The first spiral wiring portion 55 and the sixth wiring portion 56 are formed on the first surface portion of the second wiring forming layer 37 so as to be. In other words, the extending direction of a part L1 of the first spiral wiring part 55 and the extending direction of a part L2 of the sixth wiring part 56 are the same, and a part of the first spiral wiring part 55. The first spiral wiring portion 55 and the sixth wiring portion 56 are placed on the second wiring forming layer 37 so that the direction of the current flowing through L1 and the direction of the current flowing through a part of the sixth wiring portion 56 L2 are opposite to each other. It is formed on the first surface. As a result, a part L1 of the first spiral wiring part 55 and a part L2 of the sixth wiring part 56 are electromagnetically coupled.

Here, the direction of the current flowing through a part L1 of the first spiral wiring portion 55 and the direction of the current flowing through a part L2 of the sixth wiring portion 56 are opposite to each other, that is, a part of the first spiral wiring portion 55. It means that the directions of the magnetic fluxes surrounding L1 and a part L2 of the sixth wiring portion 56 are opposite to each other.

In the present embodiment, a part L1 of the first spiral wiring part 55 and a part L2 of the sixth wiring part 56 are designed to have a coupling coefficient of 0.3 and are electromagnetically coupled.

In the present embodiment, the first surface portion of the second wiring forming layer 37 is provided so that a part L1 of the first spiral wiring portion 55 and a part L2 of the sixth wiring portion 56 can be electromagnetically coupled to each other. 1 No other wiring is formed between a part L1 of the spiral wiring part 55 and a part L2 of the sixth wiring part 56.

As described above, according to the demultiplexer 10 of the present embodiment, the first spiral wiring portion 55 and the sixth wiring portion 56 are the extending direction of a part L1 of the first spiral wiring portion 55 and the sixth wiring portion. It is formed so that the angle formed by the extending direction of a part of 56 L2 on a predetermined virtual plane is 0 degree. In other words, in the first spiral wiring portion 55 and the sixth wiring portion 56, the extending direction of a part L1 of the first spiral wiring portion 55 and the extending direction of a part L2 of the sixth wiring portion 56 are the same. Is formed to be. Further, in the first spiral wiring portion 55 and the sixth wiring portion 56, the direction of the current flowing through a part L1 of the first spiral wiring portion 55 and the direction of the current flowing through a part L2 of the sixth wiring portion 56 are opposite to each other. It is formed so as to become.

When a part L1 of the first spiral wiring part 55 and a part L2 of the sixth wiring part 56 are brought close to each other, the mutual induction coupling becomes large, and the direction of the current flowing through the part L1 of the first spiral wiring part 55 and the first 6 The direction of the current flowing through part L2 of the wiring part 56 is opposite, in other words, the direction of the magnetic flux surrounding part L1 of the first spiral wiring part 55 and part L2 of the sixth wiring part 56 is opposite. Therefore, the magnetic fluxes cancel each other out, and the inductance of the sixth wiring portion 56 becomes apparently small.

A series resonant circuit is formed by the mutual inductance formed by the capacitor of the transmission filter 11, a part L1 of the first spiral wiring part 55 and a part L2 of the sixth wiring part 56, and the inductance of the sixth wiring part 56. Will be done. When the mutual inductance formed by a part L1 of the first spiral wiring part 55 and a part L2 of the sixth wiring part 56 becomes large, the mutual induction coupling becomes large, and the current flowing through a part L1 of the first spiral wiring part 55 becomes large. Since the direction of is opposite to the direction of the current flowing through a part L2 of the sixth wiring portion 56, the resonance frequency of the series resonant circuit rises.

As described above, the extending direction of a part L1 of the first spiral wiring part 55 and the extending direction of a part L2 of the sixth wiring part 56 should be the same, and a part of the first spiral wiring part 55. The reception filter 12 is formed by forming the first spiral wiring portion 55 and the sixth wiring portion 56 so that the direction of the current flowing through L1 and the direction of the current flowing through a part of the sixth wiring portion 56 L2 are opposite to each other. The series resonant circuit can be resonated outside the passing frequency band on the high frequency side of the transmission filter 11 having a passing frequency band lower than the passing frequency band of the above, and the attenuation pole can be provided relatively easily. As a result, the amount of attenuation outside the passing frequency band on the high frequency side of the transmission filter 11, in other words, in the attenuation region on the high frequency side, can be increased, and the attenuation characteristics can be improved.

Further, since the amount of attenuation outside the passing frequency band on the high frequency side of the transmission filter 11 can be increased, the leakage of the signal from the transmission filter 11 to the reception filter 12 can be reduced as much as possible, and the transmission filter 11 can be reduced. It is possible to improve the isolation characteristics outside the passing frequency band on the high frequency side.

Further, according to the demultiplexer 10 of the present embodiment, a part L1 of the first spiral wiring part 55 and a part L2 of the sixth wiring part 56 are the same layer of the mounting board 35, specifically, the second. It is formed on the wiring forming layer 37. Therefore, the number of laminated mounting boards 35 can be reduced as compared with the case where a part L1 of the first spiral wiring part 55 and a part L2 of the sixth wiring part 56 are formed in different layers of the mounting board 35, respectively. , It is possible to reduce the size of the mounting substrate 35 in the thickness direction.

FIG. 5 is a block diagram showing a configuration of a communication device 100 according to an embodiment of the present invention. The communication device 100 is realized by, for example, a mobile phone. The communication device 100 includes a transmission / reception unit 101, a control unit 102, a microphone 103, a speaker 104, and an operation unit 105. The transmission / reception unit 101 includes an antenna 110, a demultiplexer 10, and a transmission / reception processing unit 111. The transmission / reception processing unit 111 includes a digital signal processor (abbreviation: DSP) 115, a modulator 116, a first mixer unit 117, a local oscillator 118, and a first bandpass filter (hereinafter referred to as first BPF) 119. , Power amplifier 120, low noise amplifier 121, second bandpass filter (hereinafter referred to as "second BPF") 122, second mixer unit 123, lowpass filter (hereinafter referred to as "LPF") 124, and demodulator 125. The control unit 102 is connected to the transmission / reception unit 101. The microphone 103, the speaker 104, and the operation unit 105 are connected to the control unit 102.

The operation unit 105 has a plurality of operation pieces such as operation keys operated by the operator. When each operation piece is operated, the operation unit 105 generates a signal representing information corresponding to the operation, such as numerical information, character information, and predetermined information such as instruction information to the communication device main body, and the control unit 102. Give to. Therefore, the operator can operate each operation piece of the operation unit 105 to give information to the communication device main body. The control unit 102 is realized including, for example, a central processing unit (abbreviation: CPU), and based on a control program stored in the control unit 102, a transmission / reception unit 101, a microphone 103, a speaker 104, and an operation unit 105. Is controlled comprehensively.

The operation unit 105 is operated by the operator, and the sound input to the microphone 103 is converted from an analog signal to a digital signal by the analog / digital (abbreviation: A / D) conversion process by the control unit 102 and given to the DSP 115. .. The DSP115 compresses the audio signal given by the control unit 102, synchronizes the audio signal based on the Time Division Multiple Access (TDMA) method, and then shapes the waveform to generate a baseband signal. To do. The modulator 116 converts the baseband signal into an analog signal by digital / analog (abbreviation: D / A) conversion processing, and generates a modulated wave based on a predetermined modulation method of the mobile phone. In the first mixer unit 117, the oscillation signal of the predetermined oscillation frequency generated by the local oscillator 118 is multiplied by the modulated wave given by the modulator 116 to perform frequency conversion. In the first BPF 119, the unnecessary signal contained in the frequency-converted signal is attenuated by the first mixer unit 117, then the signal is amplified to a desired signal strength by the power amplifier 120, and the signal is amplified from the antenna 110 through the demultiplexer 10 to the others. Send to the communication device of.

Further, the signal received by the antenna 110 is given to the low noise amplifier 121 through the demultiplexer 10 and amplified, and then the unnecessary signal included in the signal is attenuated by the second BPF 122 and given to the second mixer unit 123. The second mixer unit 123 multiplies the oscillation signal of the predetermined oscillation frequency generated by the local oscillator 118 with the signal given from the second BPF 122 to perform frequency conversion. The LPF124 removes a signal having an unnecessary frequency from the frequency-converted signal, passes a signal in a frequency band below a predetermined cutoff frequency, and gives the signal to the demodulator 125. The demodulator 125 demodulates the signal given from the LPF 124 into an audio signal, converts the demodulated audio signal into a digital signal by A / D conversion processing, and gives it to the DSP 115. In the DSP 115, after the digital signal given from the demodulator 125 is decompressed and compressed, the DSP 115 is converted into an analog signal by the D / A conversion process, and the sound is output from the speaker 104.

As described above, according to the communication device 100 of the present embodiment, the transmission / reception processing unit 111 connects the antenna 110 to the common terminal 13 by giving a signal to the first signal input unit 25 of the demultiplexer 10. A signal can be transmitted to another communication device via the device. Further, the transmission / reception processing unit 111 can receive a signal transmitted from another communication device by receiving a signal given from the second signal output unit 31 of the demultiplexer 10. The communication device 100 can improve the attenuation characteristic of the transmission filter 11 outside the high frequency side passing frequency band, and can also improve the isolation characteristic of the transmission filter 11 outside the high frequency side passing frequency band. Since the demultiplexer 10 of the above is provided, it is possible to realize a communication device 100 capable of transmitting and receiving excellent quality signals without transmitting or receiving unnecessary signals outside the passing frequency band. Can be done.

Next, the demultiplexer of the second embodiment of the present invention will be described. 6A to 6G are diagrams showing the wiring structure of the mounting board 90. FIG. 6A is a plan view seen from the thickness direction of the mounting substrate 90, FIG. 6B is a cross-sectional view showing the first wiring cambium 36 seen from the cut plane line AA of FIG. 3, and FIG. 6C is a cross-sectional view of FIG. It is sectional drawing which shows the 2nd wiring formation layer 37 seen from the cut plane line BB, and FIG. 6D is the sectional view which shows the 2nd wiring formation layer 37 seen from the cut plane line CC of FIG. FIG. 6E is a cross-sectional view showing the third wiring forming layer 38 seen from the cutting plane line DD of FIG. 3, and FIG. 6F is a cross-sectional view showing the third wiring forming layer 38 seen from the cutting plane line EE of FIG. FIG. 6G is a bottom view showing the mounting board 90. FIG. 7 is a cross-sectional view showing the wiring structures of the second and third wiring cambium 37, 38 as seen from the cut plane line BB of FIG. In FIG. 7, the third wiring forming layer 38 is shown by a solid line, and the second wiring forming layer 37 is shown by a two-dot chain line.

Since the demultiplexer of the present embodiment is similar to the demultiplexer 10 of the first embodiment described above, only the different parts will be described, and the parts corresponding to the first embodiment are the same. The common description is omitted in order to avoid duplication.

In the mounting board 90, similarly to the mounting board 35, the first to third wiring forming layers 36 to 38 are laminated in the order of the third wiring forming layer 38, the second wiring forming layer 37, and the first wiring forming layer 36. It is a multi-layer wiring board with a multi-layer structure, and is realized by, for example, an LTCC substrate.

The second wiring 18 of the present embodiment is the same as that of the first embodiment, that is, the first wiring portion 40, the sixth wiring portion 56, the tenth wiring portion 71, the first via 46, and the sixth. The via 61 and the twelfth via 75 are included, but the formation positions are different. The first wiring portion 40 of the present embodiment is formed closer to the first end portion than the central portion in the longitudinal direction of the first wiring forming layer 36 and at the central portion in the width direction. The sixth wiring portion 56 is formed at a position closer to the first end portion than the central portion in the longitudinal direction of the second wiring forming layer 37 and closer to the second side portion than the central portion in the width direction. The tenth wiring portion 71 is formed at a position closer to the second side portion than the central portion in the longitudinal direction and the central portion in the width direction of the third wiring forming layer 38. The sixth via 61 of the present embodiment is formed at a position closer to the second side than the sixth via 61 of the first embodiment. The twelfth via 75 of the present embodiment is formed at a position closer to the second side and closer to the first end than the twelfth via of the first embodiment.

In the present embodiment, a part L1 of the first wiring and a part L2 of the second wiring are formed in different layers of the mounting board 35. Specifically, a part of the second spiral wiring part 70 corresponding to a part L1 of the first wiring is formed on the third wiring forming layer 38, and a sixth wiring part corresponding to a part L2 of the second wiring is formed. A part of 56 is formed in the second wiring forming layer 37. Hereinafter, "a part of the second spiral wiring portion 70" will be described with a reference code "L1", and "a part of the sixth wiring portion 56" will be described with a reference code "L2".

Furthermore, when the second wiring forming layer 37 is laminated on the third wiring forming layer 38, as shown in section XI of FIG. 7, when viewed from the thickness direction of the second and third wiring forming layers 37 and 38, The second spiral wiring portion 70 is formed on the third wiring forming layer 38 so that a part L1 of the second spiral wiring portion 70 and a part L2 of the sixth wiring portion 56 overlap, and the sixth wiring portion 56 is formed on the third wiring portion 56. 2 It is formed on the wiring formation layer 37.

Furthermore, on a virtual one plane orthogonal to the thickness direction of the second and third wiring forming layers 37 and 38, the extending direction of a part L1 of the second spiral wiring part 70 and a part of the sixth wiring part 56. The angle formed by the extending direction of L2 is less than 90 degrees, so that it is 0 degrees in this embodiment, and the direction of the current flowing through a part L1 of the second spiral wiring part 70 and one of the sixth wiring parts 56. The second spiral wiring portion 70 is formed in the third wiring forming layer 38, and the sixth wiring portion 56 is formed in the second wiring forming layer 37 so that the direction of the current flowing through the portion L2 is opposite. In other words, the extending direction of a part L1 of the second spiral wiring part 70 and the extending direction of a part L2 of the sixth wiring part 56 are the same, and a part of the second spiral wiring part 70. The second spiral wiring portion 70 is formed in the third wiring forming layer 38 so that the direction of the current flowing through L1 and the direction of the current flowing through a part of the sixth wiring portion 56 L2 are opposite to each other, and the sixth wiring portion is formed. 56 is formed in the second wiring forming layer 37. As a result, a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 shown in section XI of FIG. 7 are electromagnetically coupled.

Here, the direction of the current flowing through a part L1 of the second spiral wiring part 70 and the direction of the current flowing through a part L2 of the sixth wiring part 56 are opposite to each other, that is, a part of the second spiral wiring part 70. It means that the directions of the magnetic flux surrounding L1 and a part L2 of the sixth wiring portion 56 are opposite to each other.

In the present embodiment, a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 are designed to have a coupling coefficient of 0.4 and are electromagnetically coupled.

In the present embodiment, the thicknesses of the second and third wiring forming layers 37 and 38 so that a part L1 of the second spiral wiring portion 70 and a part L2 of the sixth wiring portion 56 can be electromagnetically coupled to each other. No other wiring is formed between a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 in the direction.

As described above, according to the demultiplexer of the present embodiment, the second spiral wiring portion 70 and the sixth wiring portion 56 are the extending direction of a part L1 of the second spiral wiring portion 70 and the sixth wiring portion 56. It is formed so that the angle formed by the extending direction of a part of L2 on a virtual plane defined in advance is 0 degree. In other words, in the second spiral wiring portion 70 and the sixth wiring portion 56, the extending direction of a part L1 of the second spiral wiring portion 70 and the extending direction of a part L2 of the sixth wiring portion 56 are the same. Is formed to be. The part L1 of the second spiral wiring part 70 and the part L2 of the sixth wiring part 56 are the direction of the current flowing through the part L1 of the second spiral wiring part 70 and the part L2 of the sixth wiring part 56. It is formed so that the direction of the current flowing through it is opposite to that of the current.

When a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 are brought close to each other, the mutual induction coupling becomes large, and the direction of the current flowing through the part L1 of the second spiral wiring part 70 and the second 6 The direction of the current flowing through part L2 of the wiring part 56 is opposite, in other words, the direction of the magnetic flux surrounding part L1 of the second spiral wiring part 70 and part L2 of the sixth wiring part 56 is opposite. Therefore, the magnetic fluxes cancel each other out, and the inductance of the sixth wiring portion 56 becomes apparently small.

A series resonant circuit is formed by the mutual inductance formed by the capacitor of the transmission filter 11, a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56, and the inductance of the sixth wiring part 56. Will be done. When the mutual inductance formed by a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 becomes large, the mutual induction coupling becomes large, and the current flowing through a part L1 of the second spiral wiring part 70 becomes large. Since the direction of is opposite to the direction of the current flowing through a part L2 of the sixth wiring portion 56, the resonance frequency of the series resonant circuit increases.

As described above, the extending direction of a part L1 of the second spiral wiring part 70 and the extending direction of a part L2 of the sixth wiring part 56 should be the same, and a part of the second spiral wiring part 70. The reception filter 12 is formed by forming the second spiral wiring portion 70 and the sixth wiring portion 56 so that the direction of the current flowing through L1 and the direction of the current flowing through a part of the sixth wiring portion 56 L2 are opposite to each other. The series resonant circuit can be resonated outside the passing frequency band on the high frequency side of the transmission filter 11 having a passing frequency band lower than the passing frequency band of the above, and the attenuation pole can be provided relatively easily. As a result, the amount of attenuation outside the passing frequency band on the high frequency side of the transmission filter 11 can be increased, and the attenuation characteristics can be improved.

Further, since the amount of attenuation outside the passing frequency band on the high frequency side of the transmission filter 11 can be increased, the leakage of the signal from the transmission filter 11 to the reception filter 12 can be reduced as much as possible, and the transmission filter 11 can be reduced. It is possible to improve the isolation characteristics outside the passing frequency band on the high frequency side.

In the present embodiment, as shown in FIG. 7, the second spiral wiring portion 70 is viewed from the thickness direction of the second and third wiring cambium 37, 38 (hereinafter, referred to as layer thickness direction). The second spiral wiring portion 70 is formed on the third wiring forming layer 38 and the sixth wiring portion 56 is formed on the second wiring forming layer 37 so that a part L1 and a part L2 of the sixth wiring portion 56 overlap. are doing. In other words, a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 are formed at a predetermined interval in the thickness direction of the layer. As a result, a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 are viewed from the facing area, in other words, the thickness direction of the layer, as compared with the case where they are formed in the same layer. The area where a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 overlap can be increased.

In order to increase the coupling between a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56, the facing area is increased so that one of the second spiral wiring parts 70 in the thickness direction of the layer The distance between the part L1 and a part L2 of the sixth wiring part 56 may be reduced. Further, in order to obtain the same degree of coupling between a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56, the second spiral wiring part in the thickness direction of the layer increases as the facing area increases. It is necessary to widen the distance between a part L1 of 70 and a part L2 of the sixth wiring part 56.

Since the facing area can be increased in the present embodiment, the coupling between the partial L1 of the second spiral wiring portion 70 and the partial L2 of the sixth wiring portion 56 is more than that of the first embodiment described above. It can be made even larger, and the inductance due to mutual induction coupling can be easily adjusted.

Further, according to the demultiplexer of the present embodiment, a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 are different layers of the mounting board 35, specifically, the third wiring. It is formed on the forming layer 38 and the second wiring forming layer 37. Therefore, a part L1 of the second spiral wiring part 70 is formed as compared with the case where a part L1 of the second spiral wiring part 70 and a part L2 of the sixth wiring part 56 are formed on the same layer of the mounting board 35. The area of the first surface portion of the second wiring forming layer 37 on which a part L2 of the third wiring forming layer 38 and the sixth wiring portion 56 is formed can be reduced. As a result, it is possible to reduce the size of the mounting substrate 35 in the direction orthogonal to the thickness direction.

In the first embodiment described above, the communication device 100 including the demultiplexer 10 has been described, but instead of the demultiplexer 10, the communication device 100 including the demultiplexer of the present embodiment is provided. In the same manner as in the first embodiment described above, a signal having excellent quality may be transmitted and received without transmitting or receiving an unnecessary signal outside the passing frequency band. It is possible to realize a communication device 100 capable of performing.

(Example) Examples and comparative examples of the demultiplexer 10 will be described below. As the material of the mounting substrate 35 constituting the demultiplexer 10, LTCC having a three-layer structure was used. LTCC uses alumina as the main raw material and has a relative permittivity of 9.4. The thickness dimension per layer of LTCC is 0.125 mm, the surface of each layer is formed of silver electrodes, and the minimum width dimension of the electrodes is 0.075 mm. Further, the diameter dimension of the via for connecting the electrodes formed on the surface of each layer is 0.1 mm, and the inside is filled with silver.

Further, in order to form a demultiplexer in the 800 MHz band, a filter having a pass frequency band of 824 MHz to 849 MHz was used as a transmission filter, and a filter having a pass frequency band of 869 MHz to 894 MHz was used as a reception filter.

In this example, the SAW element was formed using a thin film process. As the piezoelectric substrate 201, lithium tantalate (LiTaO)₃) A single crystal was used. A titanium (Ti) thin film having a thickness dimension of 6 nm is formed on the main surface of the piezoelectric substrate 201 in the thickness direction (hereinafter, may be simply referred to as main surface), and the surface of the Ti thin film in the thickness direction is formed. An aluminum-copper (Al-Cu) thin film having a thickness of 130 nm was formed, and three layers of each were alternately laminated to form a total of six Ti / Al-Cu laminated films.

Next, the photoresist was applied by a resist coating apparatus so that the thickness dimension was about 0.5 μm. Next, a photoresist pattern was formed by a reduced projection exposure apparatus. Next, the photoresist of the unnecessary portion was dissolved with an alkaline developer by a developing device, and an electrode pattern was formed by a reactive ion etching (abbreviation: RIE) device. Next, a protective film was formed in a predetermined region of the electrode pattern. Specifically, silica (SiO) with a thickness dimension of about 0.02 μm is used on the electrode pattern and the main surface of the piezoelectric substrate by a thermochemical vapor deposition (abbreviation: CVD) device.₂) A film was formed.

Next, the photoresist was patterned by photolithography, and the protective film of the electrode portion for the flip chip was etched by a RIE apparatus or the like. Next, a laminated electrode composed of chromium (Cr), nickel (Ni) and gold (Au) was formed using a sputtering apparatus. The thickness dimension of the laminated electrode formed was about 1 μm. Next, the photoresist and the laminated electrodes at unnecessary portions were simultaneously removed by the lift-off method to form a pad for connecting the bumps for flip chips. Next, the piezoelectric substrate 201 was diced along the dicing wire, and each chip of the SAW element was divided.

FIG. 8 is a diagram schematically showing the SAW element 200. The SAW element 200 includes a transmission filter 11 and a reception filter 12. The transmission filter 11 is a ladder type filter composed of series resonators 203a, 203b, 203c, 203d forming series arms and parallel resonators 204a, 204b forming parallel arms. The reception filter 12 is a ladder type filter composed of series resonators 205a, 205b, 205c, 205d forming series arms and parallel resonators 206a, 206b, 206c, 206d forming parallel arms.

Next, an electrode pattern made of solder was printed on the surface of the mounting substrate 35 made of LTCC in the thickness direction. Next, using a flip-chip mounting device, the electrode forming surface of each chip of the SAW element 200 faces the surface on which the electrode pattern is printed on the LTCC substrate, and the mounting substrate 35 composed of each chip and the LTCC is temporarily mounted. It was glued. Next, nitrogen gas (N₂) The chips and the LTCC substrate were adhered by baking in an atmosphere and melting the solder. Next, a resin is applied to the LTCC substrate to which the chips are adhered, and N₂Baking was performed in an atmosphere, and each of the chips was resin-sealed. Next, the mounting substrate 35 was diced along the dicing line and divided into a plurality of parts to produce the demultiplexer 10 of the present invention.

Part L1 of the first wiring connected to the first signal output unit 26 of the transmission filter 11, the second signal input unit 30 of the reception filter 12, and the ground terminal 14, and the first ground unit 27 and the ground terminal of the transmission filter 11. Part of the second wiring L2 connected to 14 is 0.075 so that the extending direction of part L1 of the first wiring 17 and the extending direction of part L2 of the second wiring 18 are the same. It is arranged with an interval of mm. The matching circuit formed in a part of the first wiring 17 is composed of the first spiral wiring portion 55, the second spiral wiring portion 70 and the tenth via 65 of the first wiring 17, and the length dimension thereof is 10.37 mm. , The inductance is 7.9nH. Further, the length dimension of a part L1 of the first wiring is 0.5 mm, and the inductance is 0.25 nH.

The second wiring 18 includes the first wiring portion 40, the sixth wiring portion 56, the tenth wiring portion 71, the first via 46, the sixth via 61, and the twelfth via 75, and the length dimension thereof is It is 1.0 mm and has an inductance of 0.69 nH. The length of part L2 of the second wiring is 0.55 mm, and the inductance is 0.33 nH.

Further, in the part L1 of the first wiring and the part L2 of the second wiring, the direction of the current flowing through the part L1 of the first wiring and the direction of the current flowing through the part L2 of the second wiring are opposite to each other. It is arranged so as to be. The distance between a part L1 of the first wiring and a part L2 of the second wiring is 0.075 mm, the mutual inductance is 0.12 nH, and the coupling coefficient is 0.4. Here, the values of each inductance and coupling coefficient are obtained using "Q3D Extractor", which is simulation software manufactured by Unsoft.

The attenuation characteristics and isolation characteristics were measured using a demultiplexer 10 manufactured by flip-chip mounting the SAW element 200 on the mounting substrate 35 having the above-mentioned configurations shown in FIGS. 4A to 4G. The isolation characteristic is the characteristic of the signal leaked from one filter to the other filter. In this embodiment, the RF signal is applied to the first signal input unit 25 of the transmission filter 11, and the signal from the second signal output unit 31 of the reception filter 12 is measured to obtain the first signal input unit 25 and the second signal input unit 25. The isolation characteristics with the signal output unit 31 were evaluated.

The measurement results of the damping characteristics and the isolation characteristics of the examples are shown in FIG. The horizontal axis of the graph shown in FIG. 9 represents frequency (unit: MHz), and the vertical axis represents attenuation and isolation (unit: dB). In FIG. 9, the attenuation characteristics of the transmission filter 11 are shown by a thick solid line, the attenuation characteristics of the reception filter 12 are shown by a thin solid line, and the isolation characteristics are shown by a broken line.

From the measurement results shown in FIG. 9, the demultiplexer of this embodiment is described later in the transmission frequency band outside the transmission filter 11 and in the transmission frequency band of the reception filter 12, in other words, in the attenuation region on the high frequency side of the transmission filter 11. It can be seen that it has better attenuation characteristics and isolation characteristics than the demultiplexer of the comparative example.

(Comparison example) In the comparative example, a part L1 of the first wiring connected to the first signal output unit 26 of the transmission filter 11, the second signal input unit 30 of the reception filter 12, and the ground terminal 14, and the first ground portion of the transmission filter 11 Part of the second wiring L2 connected to 27 and the ground terminal 14 is at a position where the extending direction of part L1 of the first wiring and the extending direction of part L2 of the second wiring do not face each other. Arranged at intervals of 0.2 mm. Further, in the part L1 of the first wiring and the part L2 of the second wiring, the direction of the current flowing through the part L1 of the first wiring and the direction of the current flowing through the part L2 of the second wiring are different. Arranged in opposite directions. The coupling coefficient between a part L1 of the first wiring and a part L2 of the second wiring is less than 0.1. The structure of the mounting board 35 and the pass frequency bands of the transmission filter 11 and the reception filter 12 are the same as those in the embodiment.

Figure 10 shows the measurement results of the damping characteristics and isolation characteristics of the comparative example. The horizontal axis of the graph shown in FIG. 10 represents frequency (unit: MHz), and the vertical axis represents attenuation and isolation (unit: dB). In FIG. 10, the attenuation characteristics of the transmission filter 11 are shown by a thick solid line, the attenuation characteristics of the reception filter 12 are shown by a thin solid line, and the isolation characteristics are shown by a broken line.

From the measurement results shown in FIG. 10, the demultiplexer of the comparative example is carried out as described above in the transmission frequency band outside the transmission filter 11 and in the pass frequency band of the reception filter 12, in other words, in the attenuation region on the high frequency side of the transmission filter 11. It can be seen that the attenuation characteristics and isolation characteristics are inferior to those of the example demultiplexer.

Table 1 shows the measurement results of the attenuation and isolation at 894 MHz in the attenuation region on the high frequency side of the transmission filter 11.

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As shown in Table 1, the attenuation of the comparative example at 894 MHz, which is the attenuation region on the high frequency side of the transmission filter 11, is -35.3 dB, and the isolation of the comparative example is -36.2 dB. On the other hand, the attenuation of the embodiment at 894 MHz, which is the attenuation region on the high frequency side of the transmission filter 11, is -48.3 dB, and the isolation is -46.3 dB. Therefore, the damping characteristics and isolation characteristics of the examples were improved as compared with the damping characteristics and isolation characteristics of the comparative examples.

Further, by implementing the present invention, improvement of the attenuation characteristic and isolation characteristic outside the pass frequency band of the reception filter 12, that is, the pass frequency band on the high frequency side of the transmission filter 11, which has been difficult in the past, and demultiplexing. It was possible to reduce the size of the vessel 10 at the same time. The length dimension in the longitudinal direction, the length dimension in the width direction, and the length dimension in the thickness direction of the demultiplexer 10 of the present invention are 2.5 mm, 2.0 mm, and 0.8 mm, respectively.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in each of the above-described embodiments, the case where a ladder type filter is used as the filter has been described, but a DMS (Double Mode SAW) type filter and an IIDT (Interdigitated Interdigital Transducer) type filter are used as a part of the filter. You may. That is, the expression of the present invention is conditional on having parallel arms, and the configuration of the filter is not particularly limited as long as it has parallel arms. Further, in each of the above-described embodiments, the case where the SAW filter is used has been described, but a piezoelectric thin film resonator (Film Bulk Acoustic Resonator; abbreviation: FBAR) filter may be used. Even when such a DMS type and IIDT type filter and an FBAR filter are used, the same effect as that of each of the above-described embodiments can be achieved.

The present invention can be practiced in various other forms without departing from its spirit or key features. Therefore, the above-described embodiment is merely an example in all respects, and the scope of the present invention is shown in the claims and is not bound by the text of the specification. Furthermore, all modifications and modifications that fall within the scope of the claims are within the scope of the present invention.