antenna coupler

0001The invention relates to an antenna coupler for testing Transmitters and / or receivers, especially mobile phones or devices that operate on the Blue Tooth standard.

0002From DE 197 32 639 C1 an antenna coupler for testing known from mobile phones. In the known Antenna, a receiving element for a mobile telephone mounted on a circuit board. is on the board formed in stripline technology a rod antenna, the acts in particular as a dipole antenna. An essential Property of the antenna coupler is the coupling factor, wherein the ratio of the received power with respect to the total power radiated indicates. Since the known Arrangement extremely sensitive to changes in position of the antenna of the mobile phone responds, is the coupling factor for each fixed to the receiving element type mobile phone differently.

0003The object of the invention is therefore, to an antenna create the opposite situation changes the antenna Transmitter and / or receiver is independent and which adopting a common coupling factor for testing variety of transmitters and / or receivers suitable.

0004The object is achieved by an antenna with the Features of claim 1. advantageous Further developments of the invention are defined in the subclaims indicated.

0005According to the invention the antenna element is spatially as in substantially closed loop formed. This next to the electric component of the mobile telephone of radiated field also detects the magnetic component. Conversely, the transmission to the mobile telephone improved. The term mobile phone is here, and Below treated as a possible application. Instead of the mobile phone, the invention is also for any other transmitter and / or receiver, z. B. those which operate according to the Blue-Tooth principle. Thereby is the coupling factor of the invention Antenna coupler largely independent of the exact Positioning the mobile phone relative to the Antenna element. Therefore, a mobile phone can be tested are, in which at least from the outside the exact position of Antenna is not known without special adaptations in terms of spatial orientation and location required are.

0006It is advantageous that the loop substantially in arranged a planes to parallel a Reflector plate is oriented. This reverse ratio is the forward / the antenna coupler crucial improved.

0007It is furthermore advantageous in that a further antenna element is provided which is designed so that in order to Transmission of the same frequency as that of a antenna element is suitable, and in that the feed point of the another antenna element with respect to the feeding point of the an antenna element at least substantially by 90 ° is offset. Thereby, the antenna coupler on the receiving antenna and simultaneously via the Send another antenna, wherein a maximum dephasing is achieved in order to avoid mutual interference.

0008The invention is described with reference to the Drawing explained. In the drawings:<dl tsize="6"><dt>Fig. 1</dt><dd>a first embodiment of a Antenna coupler in a top view;</dd><dt>FIG. 2</dt><dd>a section along the in FIG. 1 II Section line designated; </dd><dt>Fig. 3</dt><dd>a schematic view of the antenna element together with a measuring arrangement according to the first Embodiment;</dd><dt>Fig. 4</dt><dd>a schematic view of two antenna elements according to a second embodiment;</dd><dt>Fig. 5</dt><dd>a schematic representation of two Antenna elements according to a third Embodiment of the invention; and</dd><dt>Fig. 6</dt><dd>building a crossover between two Antenna elements and a measuring arrangement in accordance with the third embodiment of the invention may be connected.</dd></dl>

0009Fig. 1 shows an antenna 1 according to a first Embodiment of the invention in a plan view. Of the Antenna 1 is used for testing a mobile phone. 2 For this purpose, the mobile phone 2 by means of a on a Reflector plate 3 fixed receiving element 4 of the Antenna coupler positioned over an antenna element. 5 By the receiving element 4 is in this case a defined predetermined position, and a displacement of the mobile phone 2 during the measurements carried out prevented. to secure attachment of the mobile phone 2 comprises Receiving element 4 this particular multiple Locking members. 6

0010The antenna 7 of the mobile phone 2, that of the inside is the mobile phone 2 shown as a broken line, is through the attachment above the antenna element 5 arranged. Since the exact position of the antenna 7 from the outside can not be assessed readily, is also a exactly centered arrangement of the antenna 7 via the Antenna element 5 is difficult, that is, only by means of a consuming adjustment, possible. This is particularly the Situation, if mobile phones 2 are used in which the antenna 7 entirely within the housing 8 of the Mobile telephone 2 is housed. in addition it is awkward when for various mobile phones 2 a precise spatial adjustment must be carried out since then the receiving element 4 would be displaced. The This invention avoids the aforementioned problems by the coupling factor between the antenna element 5 and the antenna 7 is largely independent of the precise geometric arrangement of the antenna 7 of the mobile phone 2 is relative to the antenna element. 5

0011The antenna element 5 has an interrupted in FIG. 1 Inner conductor shown 9 and the inner conductor 5 surrounding outer conductor 10, the outer conductor 10 the Inner conductor 9 shields. Between the two conductors 9, 10 may be provided a dielectric. Preferably surrounds the outer conductor 10 the inner conductor 9 peripherally in the form of a cylinder jacket-shaped shield. The Antenna element 5 is as spatially substantially formed closed loop, between the one Feed point 11 and the one end 12 of the antenna element 5 lowest possible spacing exists. At the end of 12 Antenna element 5 is the inner conductor 9 of the outer conductor 10 brought out. The lead-out inner conductor 9 is in Section 13 of the feeding point 11 to the outer conductor 10 out to provide electrical contact between the two produce. The region 13 is preferably located in near the feed point 11th

0012The antenna element 5 is arranged in a plane 14 which is shown in FIG. 2. For this purpose, eg. From B. Teflon existing holders 15 used, the Antenna element 5 stop opposite the feed point 11th

0013Since the formed as a closed loop Antenna element 5, both oriented in the y-direction electrical component and the perpendicular to the plane 14 oriented magnetic component of the from the antenna 7 radiated electric field is measured, there is a degree of independence in the x- and y-direction at the Positioning of the mobile phone 2 or the antenna 7 of the Mobile phone 2. This also applies to transmission from the antenna element 5 to the antenna 7 of the mobile phone 2nd

0014The periphery of the arranged annularly in Fig. 1 Antenna element 5 corresponds essentially to the middle Wavelength λ, which is radiated from the antenna element 5 or is received to an advantageous emission and to reach reception characteristic. By mounting the Antenna element 5 over designed as a reflector Reflector plate 3 also results in an excellent Up / down ratio. The arrangement consists of four dipoles, the half loop at the Feed point a first λ / 2 dipole and the half loop relative to the feeding a second λ / 2 dipole represents and two additional λ / 2 dipoles by Reflector plate 3 are mirrored virtual.

0015The section shown in Fig. 2 along the in Fig. 1 marked II section line in addition, the height H, in which the antenna element 5 via the reflector plate 3 is arranged, are removed. Here, the height H equal to one eighth of the wavelength λ to which the tuned antenna element. 5 For a center frequency 2.45 GHz this results in a developed length of The antenna element 5 of about 12 cm and a height H of approximately 1.5 cm.

0016By reaching homogeneous field behavior in the z direction is Thus a z. B. structurally related height variation of Antenna 7 largely for the coupling factor achieved without influence.

0017Fig. 3 shows an antenna together with a Measuring arrangement in a schematic diagram according to the first Embodiment. The to a substantially closed circular loop bent Antenna element 5 has the outer conductor 10 and the Inner conductor 9, between which a dielectric 16 is provided. At the end 12 of the antenna element 5 is the Inner conductor 9 to the feed point 11 closest lying section 17 of the outer conductor 10 led to a electrical contact between these produce. About the Connector 18 is the antenna element 5 with a Measuring device 19 is connected, the connecting piece 18 as shown in of FIG. 2, the antenna element 5 in the region of the Feeding point 11 relative to the reflector plate 3 supported.

0018Fig. 4 shows the basic structure of a second Embodiment of the invention. Congruent Elements are in this and all other figures in matching numerals, thereby repeated description is not necessary.

0019According to the second embodiment, a first Antenna element 5 provided that the antenna element 5 of the first embodiment corresponds. In addition, a second antenna element 25 is provided that in principle the has same structure as the first antenna element fifth The second antenna element 25 therefore has an outer conductor 26, an inner conductor 27 and an open end 28. Accordingly, the antenna element 5, the inner conductor 27 in the Area of ​​the feeding point 29 of the antenna element 25 the outer conductor 26 for making electrical Contact out. In addition, a joint 30 provided that the antenna element 25 along with two not shown holders that match the holders 15, supported on a common reflector plate. 3

0020In the second embodiment of the invention is the Antenna element 25 apart from the polarization in about the same emission characteristic as the antenna element 5 exhibit. To save space, the antenna element 25 However positioned within the antenna element 5, so that its unwound length shorter than that of is the antenna element. 5 To nevertheless a good Emission of the two antenna elements 5, 25 to reach, starting from a central wavelength the antenna element 5 has a slightly larger scale and Antenna element 25 has a slightly smaller circumference have, so that an acceptable with regard to the vote Compromise results. On the other hand, the antenna element 25 also formed the same bulk as the antenna element 5 are, with this then in the z-direction (see Fig. 2) above or to arrange below the other element. to the Up / down ratio, through the reflector plate 3 is achieved, maintain, it is advantageous, when the arrangement of the two antenna elements 5, 25 something above and is carried out below the height H = λ /. 8

0021The feed point 29 of the other antenna element 25 is relative to the feeding 11 of the antenna element 5 to 90 ° offset, so that a maximum decoupling between the two antennas regarding receiving and simultaneous transmission is achieved. If both Antnennenelemente 5, 25 as a transmission antenna or as Receiving antenna are used, can be with this achieve arrangement also, that any in a Angle to the x- and y-axis of the stationary antenna Mobile phone, at least against one of the antenna elements 5, 25 is a good coupling factor has.

0022FIG. 5 shows a third embodiment, in which the antenna element 5 and another antenna element 35 are provided. The antenna element 5 is like the Antenna elements 5 of the first and second constructed embodiment. The additional antenna element 35 corresponds in its basic construction also the antenna element 5, ie an Outer conductor 36, an inner conductor 37, the lead-out of the Inner conductor 37 from the end 38 and the corresponding Connection with the outer conductor 36 in the region of the Entry point 39 and a connector 40. The corresponding developed length of the antenna element 35 However, only about half the length of the unwound The antenna element 5, so that it for transmission on the double center frequency is tuned. With the Antenna element 35 can therefore be the next fashion receive and transmit the transmission signal. The Connectors 18 and 40 of the two antenna elements 5, 35 are rotated by 180 ° to each other. By two antenna elements 5, 35 according to the third Embodiment, a broadband transmission by d it reaches the antenna coupler. 1

0023For the connection of the two antenna elements 5, 35 using the connectors 18, 40 with the meter 19 is a Crossover required between the Antenna elements 5, 35 and the measuring device 19 is switched.

0024Such a crossover is shown in Fig. 6. Around to simplify the illustration, are used for the Freuqenzweiche 50 provided for components in FIG. 6 with concrete values ​​called. However, this is only the Explanation of the preferred embodiment and provides also with regard to the frequency separation achieved no Limiting the invention since. The crossover 50 has a connection point 51, a connection point 52 for a lower frequency branch and a connection point 53 for a upper frequency branch on. The point of connection 51 is with a Node 54 is connected, via a capacitor C4 and a Coil L4 is grounded 55th Via the coil L1 is the Node 54 connected to the node 56th The node 56 is placed over the coil L3 and the capacitor C5 to ground, around the upper frequency range of on the side Connection point 53 is to terminate. In addition, the Node 56 via the coil L2 to the connection point 52 connected.

0025The node 54 is connected to node 58 via capacitor C2 connected. The node 58 is connected via the coil L5 and the Capacitor C3 connected to ground 59 to the lower Frequency range transmitted over the connection point 52 is to lock. The node 58 is also connected via the Capacitor C1 connected to the connection point 53rd

0026Preferably, the values ​​of the components are in accordance with the third embodiment: C1 = 6.8 pF, C2 = 1.5 pF, C3 = 6.8 pF, C4 = 0.8 pF, C5 = 3.9 pF, L1 = 10 nH, L2 = 3.9 nH, L3 = 1 nH, L4 = 12 nH and L5 = 3.9 nH. With these values, a frequency allocation of 0.8 GHz to 1 GHz lower frequency branch through the terminal point 52 is transmitted, and 1.7 GHz to 2 GHz in the upper Frequency branch transferred over the connection point 53 is achieved.

0027In the context of the invention are also other values ​​for the Components and / or a different frequency division possible.

0028In the described embodiments, the Inner conductor 9 of the respective antenna element to form an open antenna to the feeding point electrically performed closest portion of the outer conductor. in the Scope of the invention can, however, also the inner conductor directly attributed to the outer conductor surrounding will. The inner conductor of the respective antenna element then guided to the portion of the outer conductor of the Inner conductor spatially located closest.

0029The invention is not limited to the Embodiments limited. Particularly suitable the antenna coupler for testing any sender and / or receivers or transmitting and / or receiving devices, a preferred application in testing Mobile phones (mobile phones) is. In the Described embodiments, the mobile phone 2 on a support surface 20 of the receiving element 4 of the Antenna coupler 1 launched. The bearing surface 20 may Attending designed as a housing top, whereby it is not absolutely necessary, an additional Receiving element 4 fixed to the holding of the mobile phone 2 provide, as the coupling factor reached in significantly is independent of displacements in the y and x direction. It is more advantageous, however, nevertheless, a defined Position of the mobile phone 2 by the procedure described provide female member. 4 The housing is preferably conductive only in the area of ​​the reflector plate z. B. metal and in the other regions to avoid reflections from a non-conductive material, if necessary in the Side regions with an absorbent coating executed.