High frequency module and communication device using same

The present invention relates to a wireless communication system that transmits and receives signals of two or more different frequencies by sharing one antenna, and configures a demultiplexing circuit, a switch circuit, a low-pass filter circuit, a coupler circuit, and a high-frequency amplifier circuit on one laminated substrate. The present invention relates to a high-frequency module for multi-band and a communication device using the same.

For mobile wireless systems, for example, the EGSM (Extended Global System for Mobile Communications) system and DCS (Digital Cellular System) system, which are popular in Europe, the PCS (Personal Communication Service) system, which is popular in the United States, are used in Japan. PDC (Personal Digital Cellular) There are various systems that use time division multiple access (TDMA) such as the) method. With the rapid spread of mobile phones in recent years, especially in major metropolitan areas of developed countries, the frequency band assigned to each system cannot cover system users, making it difficult to connect or connecting in the middle of a call. Has a problem such as disconnection. Therefore, it has been proposed to allow users to use a plurality of systems, substantially increase the usable frequencies, expand the service area, and effectively utilize the communication infrastructure of each system. Conventionally, Patent Document 1 discloses a dual-band compatible high-frequency switch module used in a mobile communication device compatible with, for example, two systems, EGSM and DCS, as a compact and lightweight high-frequency circuit component compatible with a plurality of systems. Further, Patent Document 2 proposes a triple band compatible high frequency switch module used in a mobile communication device compatible with three systems of EGSM, DCS, and PCS.

Figure 6 shows an example of the block configuration of the triple band high frequency switch module. EGSM frequency band signal and DCS / PCS frequency band signal by demultiplexing circuit Dip (hereinafter, sometimes referred to as demultiplexer or diplexer, but equivalent) connected to the shared antenna ANT terminal. (Synthesized in the reverse direction, but demultiplexed in this specification), the first high-frequency switch SW1 switches between the EGSM transmission terminal Tx and the EGSM reception terminal Rx, and the second high-frequency switch SW2 Switches between the DCS / PCS transmission terminal Tx, the DCS reception terminal Rx, and the PCS reception terminal Rx. The low-pass filters LPF1 and LPF2 are inserted in the transmission path to reduce the amount of harmonic distortion generated by the power amplifier. Coupler circuits Coupler1 and Coupler2 detect and monitor the output of the power amplifier to enable stable operation. The bandpass filters SAW1, SAW2, and SAW3 remove unnecessary frequency components from the received signal from the antenna ANT, and send only the necessary components to the low noise amplifier. Therefore, power amplifiers HPA1 and HPA2 are provided in front of the EGSM transmission terminal Tx and DCS / PCS transmission terminal Tx, and low noise amplifiers LNA1 and LNA2 are provided in the rear stages of the EGSM reception terminal Rx and DCS reception terminal Rx and PCS reception terminal Rx. LNA3 is provided.

In a mobile wireless system, a control signal (power control signal) is sent from a base station to a mobile terminal (mobile phone) so that the transmission power is the minimum output required for communication in order to avoid interference with others. .. The APC (Automatic Power Control) circuit that operates based on this control signal controls the output of the high-frequency power amplifier in the transmission side output stage, and controls the gate voltage so that it becomes the output required for a call. Therefore, a circuit for detecting the power of the power amplifier unit is required. Normally, a coupler circuit is used to detect the output of a high-frequency power amplifier, which can be done by incorporating a single coupler circuit as an external component or by using a λ / 4 line on a dielectric substrate that forms a high-frequency power amplifier. A structure is adopted in which the electrode pattern is directly formed by using.

The demand for smaller and lighter mobile communication devices is still strong, and sharing of parts and modularization of integrated functions are being promoted. For example, in the circuit component surrounded by the dotted line in FIG. 6, a transmission line or a capacitor is formed by an electrode pattern in a laminated body in which dielectric sheets such as LTCC (Low Temperature Co-fired Ceramics) are stacked in multiple layers, and a diode or the like is formed. It is realized as a multi-band antenna switch module ASM mounted on a laminate (see the above patent gazette). In addition, modularization of the range surrounded by the alternate long and short dash line is also realized by mounting a discrete SAW filter on the laminate.

On the other hand, on the transmitting side of a mobile communication device, a power amplifier (high frequency amplifier, high power amplifier, etc.) of about several watts is used in order to output a signal of relatively high power. Since mobile phones and the like need to be small and have low power consumption, power amplifiers that consume most of DC power must have high DC-RF power conversion efficiency (also called power addition efficiency) and are small. Desired. Especially in mobile phones, etc., because the equipment is small and the length of talk time per battery charge is an important selling point of the product, the power amplifier can be made smaller and more efficient. Required.

Patent Document 3 discloses an example of a high-frequency module in which these high-frequency amplifiers, an antenna switch module, and a coupler are configured on one laminated substrate. In this example, the coupler was provided with a low-pass filter function, and an interference prevention grounding pattern was provided between the power amplifier, the switch circuit, and the coupler, respectively. However, this has a problem that a new resonance mode is generated between the coupler and the switch circuit, and a predetermined attenuation characteristic cannot be obtained. Further, it does not refer to the output fluctuation of the coupler circuit or the isolation of the transmission signal, and does not give consideration to the arrangement of the electrode patterns of the main line and the sub line constituting the coupler circuit.

Further, Patent Document 4 discloses a high-frequency module in which a coupler for monitoring the output power of a high-frequency amplifier is integrated and the line widths of the main line and the sub line are different from each other. However, the coupler circuit of this example is a so-called overlapping coupler circuit in which a part of the main line and the sub line are arranged side by side and overlapped with each other for a predetermined length. The electrode pattern of the lap coupler circuit has a problem that it is difficult to miniaturize because the arrangement on the dielectric layer is restricted and a large space is required.

<patcit num="1"><text>Japanese Unexamined Patent Publication No. 11-225088</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2000-165288</text></patcit><patcit num="3"><text>Japanese Unexamined Patent Publication No. 2003-8470</text></patcit><patcit num="4"><text>Japanese Unexamined Patent Publication No. 2002-43813</text></patcit>

<p>Conventionally, it has been a permanent issue to further reduce the size of the high frequency module, reduce the insertion loss, and improve the harmonic attenuation characteristics. Although there are examples of modularizing a multi-band antenna switch circuit, a high-frequency amplifier circuit, and a coupler circuit on a single laminated board, both Patent Document 3 and Patent Document 4 are provided between the coupler circuit and the switch circuit, especially in the transmission path. No improvement in isolation with the lowpass filter has been shown. In order to improve the attenuation characteristics of the low-pass filter, it is necessary to avoid output fluctuations in the coupler circuit and mutual interference of transmitted signals.</p><p>In view of these problems, the present invention is a high-frequency module in which an antenna switch circuit, a low-pass filter circuit, a coupler circuit, and a high-frequency amplifier circuit are integrally modularized in a laminated substrate, and mainly has an arrangement configuration of electrode patterns of the coupler circuit. By reviewing, it provides a small high frequency module. Further, the present invention provides a communication device such as a mobile phone using this high frequency module.</p>

<p>The present invention uses an antenna switch circuit, a low-pass filter circuit, a coupler circuit, and a circuit element configured by an electrode pattern in a laminated substrate formed by laminating a plurality of dielectric layers and a circuit element mounted on the laminated substrate. In a high-frequency module in which a high-frequency amplifier circuit is integrated, the coupler circuit has a function of monitoring the output of the high-frequency amplifier circuit, is arranged between the switch circuit and the high-frequency amplifier circuit, and is arranged between the switch circuit and the high-frequency amplifier circuit. Has a main line and a sub line, the main line and the sub line are composed of an electrode pattern in the laminated substrate, and the electrode pattern for the main line and the electrode pattern for the sub line are different in the laminated body. The high frequency module is provided on the dielectric layer, and the electrode pattern for the main line and the electrode pattern for the sub line are separately arranged in the vertical direction in the stacking direction.</p><p>Looking at the arrangement of the electrode patterns constituting the main line and the sub line of the coupler circuit of the present invention, the dielectric layer forming the sub line and the dielectric layer forming the main line are separated in the vertical direction and collectively. Since it is configured, the line lengths of the main line and the sub line can be independently changed and optimized, and the coupling amount can be easily set. Further, it can be applied to perform phase control by lengthening only the main line length.</p><p>In the high-frequency module of the present invention, the sub-line of the coupler is formed in a coil shape over two or more different dielectric layers, and two main lines of the coupler are formed under the plurality of dielectric layers constituting the sub-line. It is desirable to form over the above different dielectric layers. It is also desirable that the main line be formed in a coil shape. In this way, by using a so-called coil-type directional coupler, space can be effectively used and miniaturization can be achieved. Then, the directions of the currents are the same, and the magnetic fields between the adjacent transmission lines are strengthened to increase the coupling rate, the line length can be shortened in a small space, and the loss of the signal passing through the main line can be reduced.</p><p>In the high frequency module of the present invention, the line width of either the main line or the sub line of the coupler formed on at least one dielectric layer is different from the line width of the other line formed on the other dielectric layer. It is desirable to do so. This is carried out, for example, by making the line width of one of the plurality of dielectric layers forming the sub-line wider than the line width of the main line provided in the other dielectric layer. By adjusting the line width in this way, the impedance between the elements can be adjusted, and impedance matching can be easily performed. In addition, by forming the line width of either the sub line or the main line to be large, even if the main line and the sub line are misaligned in the plane direction, the degree of overlap between the main line and the sub line is the line. Since it is alleviated by the difference in width, the variation in the coupling amount can be reduced to a practical level.</p><p>In the high frequency module of the present invention, shield electrodes leading to the ground are formed above and below the electrode patterns constituting the main line and the sub line of the coupler circuit, and the electrode pattern constituting the main line and the sub line of the coupler circuit is formed. A through-hole electrode leading to the ground between the and the switch circuit portion in the laminated substrate, and between the electrode pattern constituting the main line and the sub line of the coupler circuit and the high frequency amplifier circuit portion in the laminated substrate. It is desirable to provide. In this way, shield electrodes having substantially the same effect as the ground electrodes are arranged in the vertical direction of the sub line and the main line, and a column leading to the ground between the switch circuit portion and the high frequency amplifier circuit portion in the laminated substrate. Since the through-hole electrodes are arranged, the magnetic field lines from the main line and the sub line of the coupler are prevented from propagating to the peripheral circuits, and at the same time, the propagation of unnecessary noise from the peripheral circuits is also prevented, so that isolation is performed. And stabilization of the coupling characteristics can be realized at the same time. In addition, mutual interference between the antenna switch circuit and the high frequency amplifier circuit is also prevented.</p><p>The high-frequency module of the present invention is provided with two high-frequency amplifier circuits and two coupler circuits, and the two coupler circuits are arranged separately in separate regions in the horizontal direction of the dielectric layer, and the above-mentioned It is desirable that each main line or sub line is arranged substantially symmetrically with respect to the center line of the dielectric layer. First, by providing a horizontal region for each of the different frequency bands, the main line and the sub line of the different frequency bands do not overlap in the vertical direction (projected from the top of the board) of the laminated board, and mutual interference occurs. It doesn't happen. Further, the main line or sub line of the coupler, which is divided into different regions in the horizontal direction of the dielectric layer for each different transmission system, is arranged substantially symmetrically with respect to the (horizontal) center line of the dielectric layer. As a result, the isolation between different transmission paths is improved, and as a result, the amount of harmonics generated from the antenna terminal of the module can be reduced. Further, the electrode arrangement in the dielectric substrate is symmetrical with respect to the in-plane, and the electrode density inside the dielectric can be made uniform. Generally, in the manufacturing process of a co-fired ceramic substrate, the dielectric substrate shrinks at a certain ratio before and after the firing process. Since this ratio changes depending on the density of the ceramic material and the electrode material of the substrate, it is possible to accurately control the substrate size after firing by making the electrode density inside the dielectric uniform.</p><p>In the high frequency module of the present invention, the electrode pattern constituting the main line of the coupler circuit is formed in a dielectric layer different from the dielectric layer in which the electrode pattern for the transmission line of the low-pass filter circuit is formed. Is desirable. In this way, the transmission line of the low-pass filter is formed in a layer different from the main line through which the transmission signal passes, so that interference of the transmission signal is suppressed, isolation is improved, and the attenuation characteristic level of the low-pass filter is improved. As a result, the amount of harmonics generated from the antenna terminal of the module can be reduced.</p><p>In the high frequency module of the present invention, it is desirable that the electrode pattern constituting the main line of the coupler circuit is arranged on the lower layer side than the electrode pattern forming the sub line. By locating the main line below the laminated substrate rather than the sub line in this way, the main line can be easily arranged close to the shield electrode (ground electrode). As a result, the leakage magnetic field from the main line is reduced, and the amount of harmonics generated can be further reduced. In addition, it is necessary to terminate one end of the sub line with a 50Ω resistor, but by arranging the sub line on the upper part of the laminated board, it is possible to minimize the routing to the 50Ω, and further miniaturization is possible. It will be possible.</p><p>In the high-frequency module of the present invention, the sub-line of the coupler circuit, the transmission line of the low-pass filter circuit, and the transmission line constituting the matching circuit of the output stage of the high-frequency amplifier circuit are layered on the laminated substrate in the thickness direction. It is desirable to form it on the side (upper layer side than 1/3 of the thickness). It is desirable that the impedance of the transmission line of the low-pass filter and the transmission line constituting the matching circuit of the output stage of the high-frequency amplifier module unit be as large as possible, and it is necessary to set the distance between the transmission line and the ground as large as possible. For this reason, the auxiliary line of the coupler, the transmission line of the low-pass filter, and the transmission line constituting the matching circuit of the output stage of the high-frequency amplifier module section are placed on the upper layer side in the dielectric substrate thickness direction, and the dielectric substrate thickness is generally abbreviated. It is formed on the upper layer side than 1/3. This makes it possible to improve the passage loss characteristic and the attenuation characteristic of the module.</p><p>In the laminated substrate used for the high frequency module of the present invention, two or more different dielectrics have a coiled electrode pattern constituting a sub line of the coupler and at least a coiled electrode pattern forming a transmission line of the low pass filter. Two or more different dielectrics having an upper layer mainly composed of an electrode pattern of a transmission line formed over the layers, a coiled electrode pattern constituting the main line of the coupler, and an electrode pattern constituting at least the capacitance of the low-pass filter. The main layer is a central layer mainly composed of capacitive electrodes provided over the layers, and a transmission line mainly provided with coiled electrode patterns constituting the transmission lines of the demultiplexing circuit and the switch circuit over two or more different dielectric layers. It is composed of a lower layer, and each of the upper layer, the middle layer, and the lower layer may be provided with a shield electrode leading to the ground. In this way, each electrode pattern is collectively formed in the vertical region of the laminated substrate, and these are separated by the ground electrode, so that interference between the upper and lower elements is suppressed. Further, in the high frequency module of the present invention, a 50Ω termination can be connected to one end of the sub line of the coupler, and the other end can be connected to an external electrode as a coupling port. This provides a high frequency module with multiple independent coupling ports for different transmission systems. Further, in the high frequency module of the present invention, a plurality of sub-lines corresponding to different transmission systems can be connected in series in a laminated substrate, one end is terminated with 50Ω, and the other end is connected to an external electrode as a coupling port. it can. This makes it possible to provide a high frequency module having a single coupling port corresponding to different transmission systems.</p>

<p>According to the present invention, it is a high-frequency module in which an antenna switch circuit, a low-pass filter circuit, a coupler circuit, and a high-frequency amplifier circuit are integrally modularized in a laminated substrate, and mainly by reviewing the arrangement configuration of the electrode pattern of the coupler circuit. A small high frequency module can be obtained. This coupler circuit can be optimized by independently changing the line lengths of the main line and the sub line, respectively, and it is easy to set the coupling amount. Further, it can also be applied to perform phase control by lengthening only the main line length. In addition, by forming the main line on a layer different from the transmission line of the low-pass filter, the isolation between the low-pass filter and the coupler can be improved, and the high-frequency module with improved attenuation characteristics of the low-pass filter can be obtained. Can be done. Further, since the coupler is composed of a coil type directional coupler, the coupling length can be easily set, the size can be reduced, and the loss can be reduced. According to the present invention, by mounting the above-mentioned high-frequency module, it is possible to make a communication device that is compact and lightweight and has high power addition efficiency.</p>

Hereinafter, an embodiment of the high frequency module of the present invention will be described with reference to the drawings, taking a mobile phone system as an example. First, in general, in a mobile phone system, in order to avoid interference with surrounding mobile phones, a control signal (power control signal) is used so that the outgoing output is the minimum power required for communication from the base station to the mobile phone. Has been sent. APC (Automatic Power) that operates based on this control signal The control) circuit controls the gate voltage of the high-frequency amplifier in the transmission side output stage so that the transmission output becomes the output required for the call. This is controlled by comparing the detection signal obtained by monitoring the power actually output from the high frequency amplifier with the coupler and the power control signal from the base station. In this way, the mobile phone communication system is constructed so that interference with other mobile phones is less likely to occur and the call quality can be maintained stably by making a call by varying the output so as to adapt to the surrounding environment. Has been done. In the European digital mobile phone system, the output detection circuit of the high frequency amplifier is roughly divided into two methods. One is to attach a coupler circuit to the output terminal of the high frequency amplifier to detect the output power, and the other is to attach a resistor of about 1 to 10Ω to the high frequency amplifier and obtain the power consumption from the voltage drop to obtain the high frequency power. There are two methods to convert to. Generally, the former is realized by forming a circuit on a laminated body, and the latter has various kinds of derivation means. For example, it can be realized by integrating circuits on mounted parts and semiconductor chips. The present invention is a case where the output power is monitored by a coupler by the former method.

An example is the range shown by the solid line in FIG. 6, that is, the EGSM, DCS, PCS triple band system, which is a demultiplexing circuit (Dip), a switch circuit (SW1, SW2), a low-pass filter circuit (LPF1, LPF2), and a coupler. This is a multi-band high-frequency module in which circuits (Coupler1, Coupler2) and high-frequency amplifier circuits (HPA1, HPA2) are configured on a single laminated substrate. Figure 1 shows an example of the equivalent circuit of the antenna switch module. Figure 2 shows an example of the equivalent circuit of the high frequency amplifier module section. FIG. 3 shows a developed view of the dielectric sheet constituting the laminated substrate. FIG. 4 shows a schematic cross-sectional view of the main part of the laminated substrate.

In FIG. 1, the demultiplexer (hereinafter referred to as diplexer) Dip is composed of transmission lines Lf1 to Lf3 and capacitances Cf1 to Cf4. The transmission line Lf2 and the capacitance Cf1 form a series resonant circuit in the DCS band (transmission frequency: 1710 to 1785MHz, reception frequency: 1805 to 1880MHz) and PCS band (transmission frequency: 1850 to 1910MHz, reception frequency: 1930 to 1990MHz). Designed to have a resonant frequency. In this example, the attenuation pole is adjusted to 1.8 GHz. In addition, the transmission line Lf3 and the capacitance Cf3 form a series resonance circuit, and are designed to have a resonance frequency in the EGSM band (transmission frequency: 880 to 915MHz, reception frequency: 925 to 960MHz). In this example, the attenuation pole is adjusted to 0.9 GHz. This circuit makes it possible to demultiplex and synthesize the EGSM system signal and the DCS / PCS system signal. The transmission line Lf1 is preferably set to a certain length so as to have high impedance for the frequency of the DCS / PCS system signal. This makes it difficult for DCS / PCS signals to be transmitted to the EGSM path. On the other hand, the capacitances Cf2 and Cf4 are preferably set to relatively small capacitance values so as to have high impedance for the frequency of the EGSM system signal. This makes it difficult for the EGSM system signal to be transmitted to the DCS / PCS system path. In addition, an inductor Lf with one end grounded between the antenna ANT and the diplexer Dip is inserted as a countermeasure against static electricity destruction. This is because when a charged charge on the human body or the like is applied from the antenna terminal, the PIN diode or GaAs semiconductor may be destroyed by the voltage surge, and the inductor Lf works to release this voltage surge to GND.

The first switch circuit SW1 is composed of capacitances Cf, Cg4, transmission lines Lg2, Lg3, PIN diodes Dg1, Dg2, and a resistor Rg. For the transmission lines Lg2 and Lg3, set the length of the transmission line so that it becomes a λ / 4 resonator in the transmission frequency band of EGSM. However, the transmission line Lg2 can be replaced with a choke coil whose ground level seems to be open (high impedance state) at the transmission frequency of EGSM. The resistor Rg determines the current flowing through the first and second diodes Dg1 and Dg2 when the control power supply VC1 is in the High state. Capacities Cf and Cg4 are required for DC cut of the control power supply. When the control power supply VC1 is High, the PIN diode Dg2 has a parasitic inductance such as a connecting wire, so that it resonates in series with the capacitance Cg4 so as to cancel this.

As described above, when the control power supply VC1 is High, both the first and second diodes Dg1 and Dg2 are turned on, the connection point between the second diode Dg2 and the transmission line Lg3 becomes the ground level, and the transmission is a λ / 4 resonator. The impedance on the opposite side of the line Lg3 becomes infinite. Therefore, when the control power supply VC1 is High, the signal cannot pass through the route between the diplexer Dip and EGSM Rx, and the signal easily passes through the route between the diplexer Dip and EGSM Tx. On the other hand, when the control power supply VC1 is Low, the first diode Dg1 is also OFF and no signal can pass through the path between the diplexer Dip and EGSM Tx, and the second diode Dg2 is also OFF. The signal easily passes through the route of. With the above configuration, it is possible to switch between transmission and reception of the EGSM signal.

The second switch circuit SW2 is composed of capacitances Cp, Cd4, Cp2, Cp4, transmission lines Ld2, Ld3, Lp2, Lp3, PIN diodes Dd1, Dd2, Dp1, Dp2 and resistors Rd and Rp. Transmission line Ld2, Ld3, Lp2, Lp3 set the length of the transmission line so that it becomes a λ / 4 resonator at the signal frequency of DCS / PCS. However, the transmission line Ld2 can be substituted with a choke coil at the DCS transmission frequency, and Lp2 can be replaced with a choke coil whose ground level appears to be open (high impedance state) at the PCS transmission frequency. The resistor Rd determines the current flowing through the third and fourth diodes Dd1 and Dd2 when the control power supply VC2 is in the High state. The resistor Rp determines the current flowing through the 5th and 6th diodes Dp1 and Dp2 when the control power supply VC3 is in the High state. Capacities Cd4, Cp, Cp4 are required for DC cut of the control power supply. When the control power supply VC2 is High, the PIN diode Dd2 has a parasitic inductance such as a connecting wire, so the capacitance value of the capacitance Cd4 is set so as to resonate in series with the capacitance Cd4.

As described above, when the control power supply VC2 is High, both the third and fourth diodes Dd1 and Dd2 are turned on, the connection point between the fourth diode Dd2 and the transmission line Ld3 is at the ground level, and the transmission is a λ / 4 resonator. The impedance on the opposite side of the line Ld3 becomes infinite. Therefore, when the control power supply VC2 is High, the signal cannot pass through the route between the diplexer Dip to PCS Rx and the diplexer Dip to DCS Rx, and the signal easily passes through the route between the diplexer Dip to DCS / PCS Tx. On the other hand, when the control terminal VC2 is Low, the third diode Dd1 is also OFF and the signal cannot pass through the path between the diplexer Dip ~ DCS / PCS Tx, and the fourth diode Dd2 is also OFF, so the diplexer Dip ~ PCS Rx And the path between the diode Dip and DCS Rx makes it easier for the signal to pass.

When the control terminal VC3 is High, the PIN diode Dp2 has a parasitic inductance such as a connecting wire, so the capacitance value of the capacitance Cp4 is set so as to resonate in series with the capacitance Cp4. As a result, when the control terminal VC3 is High, both the 5th and 6th diodes Dp1 and Dp2 are turned on, the connection point between the 6th diode Dp2 and the transmission line Lp3 becomes the ground level, and the transmission is a λ / 4 resonator. The impedance on the opposite side of the line Lp3 becomes infinite. Therefore, when the control terminal VC3 is High, the signal cannot pass through the path between DCS Rx, and the signal easily passes through the path between PCS Rx. Conversely, when the control terminal VC3 is Low, the fifth diode Dp1 is also OFF, the signal cannot pass through the path between PCS Rx, and the sixth diode Dp2 is also OFF, so the signal is off in the path between DCS Rx. It will be easier to pass. With the above configuration, when the control terminal VC2 is High, it goes to DCS / PCS Tx, and when the control terminals VC2 and VC3 are Low and High, respectively, it goes to PCS. Switching to Rx is possible when the control terminal VC2 and control terminal VC3 are Low, switching to DCS Rx.

The control logic in Table 1 is also separate from the control logic of the antenna switch module described above. In this case, VC3 was set to High in EGSM TX mode and DCS / PCS TX mode. This is for the purpose of reducing the amount of harmonics generated from the 5th and 6th diodes Dp1 and Dp2. By setting VC3 to High in the transmission mode, Dp1 and Dp2 are turned on, and the amount of harmonics generated can be reduced.

<tables num="1"><img file="JP2006191663A_D0001.tif" /></tables>

Next, the first low-pass filter LPF1 is a π-type low-pass filter composed of a transmission line Lg1 and capacitances Cg1, Cg2, and Cg3. Here, the transmission line Lg1 and the capacitance Cg1 form a parallel resonance circuit, and the resonance frequency is set to a frequency twice or three times the transmission frequency of the EGSM. In this example, it was set to 2.7 GHz, which is three times higher. With the above configuration, harmonic distortion included in the transmission signal on the EGSM side input from the power amplifier can be removed.

The second low-pass filter LPF2 is a π-type low-pass filter composed of a transmission line Ld1 and capacitances Cd1, Cd2, and Cd3. Here, the transmission line Ld1 and the capacitance Cd1 form a parallel resonance circuit, and the resonance frequency is set to a frequency twice or three times the DCS / PCS transmission frequency. In this example, it was doubled to 3.6 GHz. With the above configuration, harmonic distortion contained in the transmission signal on the DCS / PCS side input from the power amplifier can be removed.

The first coupler circuit Coupler 1 is composed of a main line Lcg1, a sub line Lcg2, and a terminating resistor Rcg. Here, one end of the transmission line constituting the main line Lcg1 is connected to the transmission line Lg1 of the first low-pass filter LPF1, and the other end is connected to the terminal port of the high-frequency amplifier HPA1. The transmission line constituting the sub line Lcg2 is arranged so as to be coupled with the main line Lcg1, and one end is grounded via a terminating resistor Rcg which is almost equal to the characteristic impedance (50Ω). The other end is connected to the monitor terminal CP1. Therefore, a part of the transmission signal of the EGSM is taken out, the power of the transmission signal coming from the transmission circuit is detected, and the detection signal is sent to the APC circuit via the detector for feedback control. Ideally, the electrical length of the main line should be about λ / 4 of the EGSM transmission frequency, but as in this embodiment, the main line and sub line are formed in a coil shape, and the width of the sub line is greater than that of the main line. When the length is increased, a sufficient amount of coupling and isolation can be secured even if the length of the main line is about λ / 8. Since the length of the main line can be shortened in the present invention, the module size can be reduced and the loss can be reduced.

The second coupler circuit Coupler 2 is composed of a main line Lcd1, a sub line Lcd2, and a terminating resistor Rcd. Here, one end of the transmission line constituting the main line Lcd1 is connected to the transmission line Ld1 of the second low-pass filter LPF2, and the other end is connected to the terminal port of the high-frequency amplifier HPA2. The transmission lines that make up the sub line Lcd2 are arranged so as to couple with the main line Lcd1 and one end is grounded via a terminating resistor Rcd that is approximately equal to the characteristic impedance (50Ω). The other end is connected to the monitor terminal CP2. Therefore, a part of the DCS / PCS transmission signal is taken out, the power of the transmission signal coming from the transmission circuit is detected, and the detection signal is sent to the APC circuit via the detector for feedback control. Ideally, the electrical length of the main line should be about λ / 4 of the DCS / CPS transmission frequency, but as in this embodiment, the main line and sub line are formed in a coil shape, and the width of the sub line is the main. When it is made larger than the line, a sufficient amount of coupling and isolation can be secured even if the length of the main line is about λ / 8. Since the length of the main line can be shortened in the present invention, the module size can be reduced and the loss can be reduced.

Next, the high frequency amplifier side will be described. FIG. 2 shows a circuit diagram of the high frequency amplifier of this embodiment. The output terminal EGSM Po at the end of the matching circuit on the high-frequency amplifier side is connected to the transmission terminal EGSM Tx in Fig. 1 and plays the role of sending the amplified transmission signal to the antenna switch side. One end of the transmission line lm1 is connected to the output terminal EGSM P0 via the DC cut capacitor ca4. Capacitors ca13, ca14, and ca15 whose ends are grounded are connected to the transmission line lm1 to form an output matching circuit. The other end of the transmission line lm1 is connected to the collector of the bipolar transistor GQ3.

The connection point between the other end of the transmission line lm1 and the collector of GQ3 is grounded via a series circuit of the inductor lm2 consisting of a λ / 4 strip line and the capacitor ca10, and the connection point between the inductor lm2 and the capacitor ca10 is the drive power supply. It is connected to Vcc2. Further, the gate of GQ3 and the collector of GQ2 are connected via the capacitor Ca3, and the bias voltage Vb3 is supplied from the power amplifier control circuit to the base side of CQ2.

The connection point of the collector of the capacitor ca3 and GQ2 is grounded via a series circuit of the inductor lm3 consisting of a λ / 4 strip line and the capacitor ca9, and the connection point of the inductor lm3 and the capacitor ca9 is connected to the drive power supply Vcc1. ing. Further, the gate of GQ2 and the collector of GQ1 are connected via the capacitor Ca2, and the bias voltage Vb2 is supplied from the power amplifier control circuit to the base side of CQ2.

The connection point of the collector of the capacitor ca2 and GQ1 is grounded via a series circuit of the inductor lm4 consisting of a λ / 4 strip line and the capacitor ca9, and the connection point of the inductor lm4 and the capacitor c9 is connected to the drive power supply Vcc1. ing. Further, the gate of GQ1 and the input terminal Gin are connected via the capacitor Ca1, and the bias voltage Vb1 is supplied from the power amplifier control circuit to the base side of CQ1.

Similarly, the output terminal DCS / PCS Po at the end of the matching circuit is connected to the transmission terminal DCS / PCS Tx in Fig. 1 and plays the role of sending the amplified transmission signal to the antenna switch side. The output terminal DCS / PCS P0, via a DC cut capacitor ca8 to one end of the transmission line lm5 is connected. Capacitors ca16, ca17, and ca18 whose ends are grounded are connected to the transmission line lm5 to form an output matching circuit. The other end of the transmission line lm5 is connected to the collector of the bipolar transistor DQ3.

The connection point between the other end of the transmission line lm5 and the collector of DQ3 is grounded via a series circuit of the inductor lm6 consisting of a λ / 4 strip line and the capacitor ca12, and the connection point between the inductor lm6 and the capacitor ca12 is the drive power supply. It is connected to Vcc4. Further, the gate of DQ3 and the collector of DQ2 are connected via the capacitor Ca7, and the bias voltage Vb6 is supplied from the power amplifier control circuit to the base side of DQ2.

The connection point of the collector of the capacitor ca7 and DQ2 is grounded via a series circuit of the inductor lm7 consisting of a λ / 4 strip line and the capacitor ca11, and the connection point of the inductor lm7 and the capacitor ca11 is connected to the drive power supply Vcc3. ing. Further, the gate of DQ2 and the collector of DQ1 are connected via the capacitor Ca6, and the bias voltage Vb5 is supplied from the power amplifier control circuit to the base side of DQ2.

The connection point of the collector of the capacitor ca6 and DQ1 is grounded via a series circuit of the inductor lm8 consisting of a λ / 4 strip line and the capacitor ca11, and the connection point of the inductor lm8 and the capacitor ca11 is connected to the drive power supply Vcc3. ing. Further, the gate of DQ1 and the input terminal Din are connected via the capacitor Ca5, and the bias voltage Vb4 is supplied from the power amplifier control circuit to the base side of DQ1.

The power amplifier control circuit adjusts the bias voltages Vb1 to 6 according to the band select voltage Vbs and the APC control voltage Vapc. This makes it possible to amplify the input signals Gin and Din and input the signal whose impedance has been converted to 50Ω by the matching circuit to the antenna switch circuit side.

Although the transmission line and the inductor are often composed of strip lines in the equivalent circuits of FIGS. 1 and 2, they may be composed of microstrip lines, coplanar guidelines, or the like. Further, on the amplifier circuit side, in this embodiment, a three-stage amplifier circuit of GQ1 to CQ3 and DQ1 to DQ3 is used, but the number of stages can be changed depending on the case. Although GQ1 to 3 and DQ1 to 3 show examples of bipolar transistors, other types of transistors may be used. For example, Si-MOSFET, GaAsFET, Si bipolar transistor, GaAsHBT (heterojunction bipolar transistor), HEMT (high electron mobility transistor) and the like can be mentioned. Of course, an MMIC (monolithic microwave integrated circuit) in which a number of transistors are integrated may be used.

Further, in the above embodiment, the EGSM system can be further divided into GSM850 (transmission frequency: 824 to 849 MHz, reception frequency: 869 to 894 MHz) and EGSM to support quad band. In this case, a common terminal can be used for the transmission system, and the reception system can be configured by connecting a switch for switching between GSM850 and EGSM to the EGSM reception terminal portion of the triple band compatible antenna switch. It can also be realized by using a transmission line which is a λ / 4 resonator in the GSM850 and EGSM bands instead of the switch and separating the frequencies between the two.

Next, the structure of the laminated substrate will be described. FIG. 3 shows a developed view of a dielectric layer (hereinafter referred to as a green sheet). FIG. 4 is a schematic cross-sectional view for explaining a main part of the present invention of a laminated substrate. By the way, in this embodiment, the transmission line of the demultiplexing circuit (Dip), the switch circuit (SW1, SW2) and a part of the capacitance, the transmission line of the low pass filter circuit (LPF1, LPF2), the coupler circuit (Coupler1, Coupler2), The transmission line of the high-frequency amplifier circuit (HPA1, HPA2) and a part of the capacitance are composed of an electrode pattern on the dielectric layer, and in Fig. 1, chip elements such as diodes, high-capacity chip capacitors, chip inductors and semiconductor elements are laminated. It is mounted on a substrate and thus constitutes a one-chip high-frequency module.

The green sheet constituting the laminated substrate is made of an LTCC material that can be co-fired at a low temperature of 950 ° C or lower. For example, Al, Si, Sr, Ti of 10 to 60% by mass in terms of Al2O3, 25 to 60% by mass in terms of SiO2, 7.5 to 50% by mass in terms of SrO, and 20% by mass or less in terms of TiO2, and 0.1 in terms of Bi2O3. ~ 10% by mass, 0.1 to 5% by mass in Na2O conversion, 0.1 to 5% by mass in K2O conversion, 0.01 to 5% by mass in CuO conversion, 0.01 to 5% by mass in MnO2 conversion Bi, Na, K, Cu, Mn A dielectric composition containing each of these is used.

The laminated substrate is made by printing a silver-based conductive paste on a green sheet having a sheet thickness of 40 to 200 μm and printing a predetermined electrode pattern constituting a transmission line and a capacitor capacity, and appropriately providing through holes to form a circuit. The sheets are laminated and crimped in sequence and fired at 950 ° C to integrate them. The size is about 8 mm in width × 8 mm in length × 1.5 mm in height, and a diode, a transistor, a chip inductor, and a chip capacitor are mounted on the upper surface, and a metal case is put on it to make a finished product. However, a resin-sealed package may be used instead of the metal case.

The laminated board constitutes a high-frequency amplifier module portion in the left side region and a switch module portion in the right side region. The electrode pattern of the high frequency amplifier module section on the left side is omitted, and the switch module section will be described below. First, a shield electrode SG that communicates with the ground on the back surface of the lowermost layer is provided between the left and right regions of the laminated substrate via a through-hole electrode. It is desirable to install shield electrodes on all green sheets if there is room in the dimensional arrangement, but in many cases this is not possible, so as shown in green sheets 3, 9, etc., strip-shaped shield electrodes SG2 and SG6 are used. In the same way, the through-hole electrodes HG1 to HG4, which are connected to the ground electrode on the back surface, are intermittently arranged in a row and provided in a bamboo blind shape to act as a shield electrode. By providing such shield electrodes SG and HG, the arrangement design of each electrode pattern can be simplified and mutual interference between high-frequency components can be suppressed. Unstable operation such as oscillation of high frequency amplifier can be prevented. Further, it is possible to suppress the generation of spurious between the required signal (transmission signal) and the unnecessary signal, and it is possible to prevent the deterioration of the passing characteristics.

The laminated substrate of the embodiment is composed of 10 layers, and the upper layer (1 to 3 layers) is mainly provided with the electrode patterns of the transmission lines constituting one of the diplexers and the sub lines of the low-pass filter and the coupler, respectively, and the middle layer. The transmission line and diplexer that make up the main line of the coupler and the electrode pattern that makes up the capacitor capacity of the switch circuit and low-pass filter are mainly provided in (4 to 8 layers), and the other side of the diplexer and the switch are provided in the lower layer (9 to 10 layers). The electrode patterns of the transmission lines that make up the circuit are mainly formed. In the following description, the laminated pattern of the portion related to the present invention will be mainly described, and the detailed description of the other laminated patterns will be omitted.

The green sheet 1 on the uppermost layer is formed with a shield electrode SG1, a land electrode for connecting a chip element to be mounted, and transmission lines lm1 and lm5 of a matching circuit of a power amplifier. The green sheet 2 has a shield electrode HG1 in which through-hole electrodes are arranged in a row, a sub line Lcg2 of a coupler 1 and a sub line Lcd2 of a coupler 2, transmission lines lm1 and lm5 of a matching circuit of a power amplifier, and a low-pass filter LPF1. The coiled electrode patterns constituting the transmission line Lg1 of the transmission line Lg1 and the transmission line Ld1 of the low-pass filter LPF2 are also provided in the same layer. At this time, the coupler sub-lines Lcg2 and Lcd2 are arranged between the transmission lines lm1 and lm5 of the matching circuit of the power amplifier and the transmission lines Lg1 and Ld1 of the low-pass filter, and the sub-lines Lcg2 of the coupler 1 and the sub-lines of the coupler 2 are arranged. A coil-shaped electrode pattern is provided in a region different from that of the Lcd2, and has a substantially target position and shape with respect to the horizontal center line CL of the sheet.

A band-shaped shield electrode SG2 is formed on the green sheet 3, and a coil-shaped electrode pattern following the sub-lines Lcg2 and Lcd2, a coil-shaped electrode pattern following the low-pass filters Lg1 and Ld1, and a matching circuit of the power amplifier are transmitted. Lines lm1 and lm5 are provided. However, the line widths of the sub lines Lcg2 and Lcd2 in this layer are made wider than the line widths of the main lines described below, and the variation in the coupling amount due to impedance matching and the positional deviation between the sheets is reduced. In addition, the transmission line Lg3 of the switch circuit SW1 is provided. The transmission lines Lf1 and Lf2 that make up the low-frequency side pass filter of the diplexer Dip are also formed on the green sheets 1 to 3.

Shield electrodes SG3, SG4, SG5 are arranged on the green sheets 4, 6 and 8 at 2/5 to 3/5 of the dielectric substrate thickness, and the area from the green sheet 1 to 5 and the area from the green sheet 6 to the back surface. It is possible to electromagnetically shield the area. As a result, the pattern arrangement can be laid out without worrying about the vertical isolation of the shield electrodes SG3, SG4, and SG5, and the module size can be reduced.

The grounding capacitances CG2 and Cd2 of the low-pass filter section, the grounding capacitances ca13 to 18 of the matching circuit, and the like are formed on the green sheet 5. Then, a coil-shaped electrode pattern constituting the main line Lcg1 of the coupler 1 and the main line Lcd2 of the coupler 2 is formed from this layer to the green sheet 6.

In addition to the shield electrode SG4, the green sheet 6 is mainly provided with main lines Lcg1 and Lcd2 and counter electrodes CG2 that continue from the upper layer. The main lines Lcg1 and Lcd2 of this layer are not clearly coiled, but it can be said that they form a coiled coupler circuit as a whole. In this way, the coiled electrode patterns that make up the main lines Lcg1 and Lcd1 are arranged near the counter electrodes CG1 and CG2 that lead to the ground, so parasitic capacitance is likely to occur, and as a result, the capacitances Cg3 and Cd3 The electrodes can be made smaller.

The green sheet 7 is formed with an electrode pattern that forms the remaining capacitance of the switch circuit, low-pass filter circuit, and diplexer circuit. As described above, the shield electrode SG5 is formed on the green sheet 8. All of the sub-lines Lcg2 and Lcd2 and the main lines Lcg1 and Lcd1 of the coupler provided on each green sheet are arranged so as to be sandwiched between the shield electrodes SG1 and SG5 when viewed from above.

The green sheets 9 and 10 are provided with an electrode pattern of a transmission line on the high-pass filter side of the diplexer and a transmission line constituting a switch circuit, a shield electrode SG6, and a columnar through-hole electrode HG4. A ground electrode GND is formed in the center of the back of the green sheet 10, and on the outer periphery, ANT terminal, receiving terminal GRx, DRx, PRx terminal, power amplifier input terminal Gin, Din, antenna switch control terminal VC1, VC2, VC3, coupler output terminals CP1, CP2, band select terminal BS, APC control terminal, power amplifier power supply terminal VCC1, VCC2, VCC3, VCC4 and GND terminals are arranged.

Figure 4 shows the sub line lcd2 and main line lcd1 of the coupler on the DCS / PCS side, the transmission line ld1 of the low-pass filter, the capacitance cd2, cd3, the transmission line lm5 of the matching circuit of the power amplifier, the capacitance ca16, ca17, ca18, and the shield electrode. It is sectional drawing which shows the arrangement structure such as. In this way, the sub line lcd2 of the coupler, the transmission line ld1 of the low-pass filter, and the transmission line lm5 of the matching circuit are formed in the same layer at the top. The main line lcd1 of the coupler is formed in a coil shape under the sub line lcd2, and is shielded by through-hole electrodes HG1, HG2, HG3 and shield electrodes SG3, SG4, SG5. This greatly improves the isolation between the transmission line lm5 of the matching circuit and the main line lcd1 and the isolation between the main line lcd1 and the transmission line ld1 of the low-pass filter. In addition, the matching circuit and the low-pass filter are separated by the shield electrodes SG1 and SG3 that include the main line and sub line of the coupler, and at the same time, the effect of electromagnetic shielding by the ground electrode is synergized. Therefore, the isolation between the functional blocks is also improved. The vertical relationship between the main line lcd1 and the sub line lcd2 of the coupler may be reversed, and the same applies to the present invention.

The characteristics of the high frequency module of the present invention are as follows. Conventionally, when transmitting GSM, the efficiency was 42%, 2nd harmonic -35dBm, 3rd harmonic -40dBm, but according to this example, the efficiency is 45%, 2nd harmonic -50dBm or less, 3 times. Harmonics -55 dBm or less and characteristic improvement was seen. On the other hand, in the DCS / PCS band, the efficiency was 33%, 2nd harmonic -35dBm, 3rd harmonic -35dBm, but according to this example, the efficiency was 35% or more, 2nd harmonic -45dBm or less. 3rd harmonic -50dBm or less was achieved. Due to the above improvement in characteristics, when this high-frequency module is used in a mobile phone, it is possible to improve the efficiency by about 5 to 10% as compared with the case where parts are mounted separately as in the conventional case. This reduces power consumption during transmission, improves battery life, and enables long-term calls with a talk time of about 5 to 10% per charge. Therefore, it is possible to meet the needs for miniaturization and weight reduction by mounting it on a communication device such as a mobile phone or a small information terminal such as a PDA.

The equivalent circuit of the antenna switch shown in Fig. 1 and the equivalent circuit of the high-frequency amplifier shown in Fig. 2 are examples. For example, the switch circuit shows an example using a PIN diode, but the switch circuit can also be configured by using an SPnT type GaAs switch such as SPDT (Single Pole Dual Throw) or SP3T. In this case, if the PIN diode switch is simply replaced with the SPDT GaAs switch, the λ / 4 line required for the PIN diode switch becomes unnecessary, so that there is a margin in the laminated body. Therefore, it is advantageous for further miniaturization and high integration by reducing this space or forming a new functional element. Further, a SAW filter may be inserted into the receiving system path for integration.

Further, in the above-described embodiment, the circuit has output terminals CP1 and CP2 for each transmission band as a coupling port, but as shown in FIG. 5, one end of the sub line lcc2 is one end of another sub line lcd2. A circuit connected to can also be adopted. According to this circuit, the output power of both the EGSM and DCS / PCS bands can be monitored by a common coupling port, and the number of parts of the detector connected to the subsequent stage can be reduced.

In addition to the above, the transmission / reception system used in the present invention includes PDC800 band (810 to 960MHz), GPS band (1575.42MHz), PHS band (1895 to 1920MHz), Bluetooth band (2400 to 2484MHz), and Wireless LAN 2. Similar effects can be expected for multi-band compatible antenna switch circuits that combine 5G and 5G bands, CDMA2000, which is expected to become popular in the United States, and TD-SCDMA, which is expected to become popular in China. Using the circuits in these cases, a multi-mode multi-band antenna switch circuit such as dual band, 3-band, 4-band, and 5-band can be obtained.

The high frequency module of the present invention can be used for communication devices such as information terminals such as mobile phones and PDAs.

<figref num="1">It is an equivalent circuit diagram on the antenna switch module side which shows one Example of the high frequency module of this invention.</figref><figref num="2">It is an equivalent circuit diagram on the high frequency amplifier side which shows one Example of the high frequency module of this invention.</figref><figref num="3">It is a green sheet development view of the laminated substrate which shows one Example of the high frequency module of this invention.</figref><figref num="4">It is a schematic cross-sectional view of the main part of a laminated substrate.</figref><figref num="5">It is an equivalent circuit diagram on the antenna switch module side which shows one Example of the high frequency module of this invention.</figref><figref num="6">It is a block diagram explaining the form of the high frequency module of this invention.</figref>

Code description

ASM: Antenna switch module HPA: High power amplifier Dip: Diodexer (demultiplexer, demultiplexer circuit) SW: Switch circuit LPF: Low-pass filter circuit Coupler: Coupler circuit SAW: Elastic surface wave filter lf1 ~ lf3, lg1 ~ lg3, ld1 ~ ld3, lp1 ~ lp3, lm1 ~ lm8, Lf, Ld: Inductor, Transmission line cf1 ~ cf4, cg1 ~ cg4, cd1 ~ cd4, cp1 ~ cp4, ca1 ~ ca18, Cd, Cp: Capacitor GQ1 ~ GQ3, DQ1 ~ DQ3: Transistors Dg1, Dg2, Dd1, Dd2, Dp1, Dp2: PIN diode SG, SG1 ~ SG7: Ground electrode HG, HG1 ~ HG4: Ground electrode with through hole