JP4276512B2 - Antenna duplexer and wireless terminal using the same - Google Patents

Description

    The present invention relates to a structure of an antenna duplexer equipped with a transmission surface acoustic wave filter and a reception surface acoustic wave filter or a transmission FBAR (Film Bulk Acoustic Resonator) filter and a reception FBAR filter, and more particularly, a code division multiple access CDMA (Code Division Multiple Access). The present invention relates to an antenna duplexer suitable for an Access system and a wireless terminal using the antenna duplexer.

 Mobile communication systems have progressed from the first generation of analog systems to the second generation of digital systems, but in recent years, multimedia services with high-speed, high-quality transmission that handle diverse contents such as voice, data, and moving images in the mobile environment. Is progressing. In addition to such voices, expansion of communication capacity and improvement of communication quality are required to support multimedia services that provide large-capacity data, still images, and moving images.

 Therefore, CDMA systems that have been put to practical use in Japan, the United States, South Korea, etc. are attracting attention, and accordingly, development of high-performance antenna duplexers for CDMA installed in mobile phones is required.

    As for the antenna duplexer, for example, the following Patent Documents 1 and 2 can be cited.

JP 2000-68785 A JP-A-9-270604

 The CDMA system, like the FDMA (Frequency Division Multiple Access) system, is a system in which transmission and reception are performed simultaneously. FIG. 9 is a schematic configuration diagram for explaining the CDMA system. In the figure, reference numeral 100 denotes an antenna, to which an antenna duplexer 101 is connected, and to this antenna duplexer 101, a reception circuit 102 and a transmission circuit 103 are directly connected.

 This CDMA method is a multiple access method in which a large number of stations in a single repeater band divide the band so that the spectrum does not overlap each other. Compared with the TDMA system, the CDMA system has features such as simplification of an antenna, a large power amplifier, a modem, and the like. In the CDMA system in which transmission and reception are performed simultaneously, sufficient suppression of each frequency band is essential between the antenna and transmission in the antenna duplexer and between the antenna and reception. Furthermore, since transmission power does not leak into reception, it is necessary to ensure sufficient isolation between transmission and reception.

    The antenna duplexer disclosed in Patent Document 1 separately provides a ground potential pattern for each of a transmission system matching circuit and a reception system matching circuit, thereby providing a surface acoustic wave filter for transmission and an elasticity for reception. It is said that the deterioration of the frequency characteristics of the surface acoustic wave filter due to mutual interference with the surface wave filter can be suppressed.

 FIG. 8 is a top view of the multilayer package substrate 36 disclosed in Patent Document 1. In FIG. In the figure, 37 is a chip mounting area, 38 is a transmission system ground potential pattern, 39 is a reception system ground potential pattern, 40 to 43 are terminals, 44 is a transmission system ground terminal, and 45 is a reception system ground terminal.

 However, this antenna duplexer has the following problems. That is, by separately providing the ground potential patterns 38 and 39 for each of the transmission system matching circuit and the reception system matching circuit, it is possible to suppress deterioration in frequency characteristics due to mutual interference between transmission and reception. However, since the ground potentials of the antenna and the transmission system and the antenna and the reception system are the same, it is not possible to suppress signal leakage between the antenna and the transmission system and between the antenna and the reception system.

 The object of the present invention is to eliminate such disadvantages of the prior art, to prevent deterioration of the frequency characteristics due to mutual interference between the antenna, the transmission system, and the reception system, and to achieve high isolation between the transmission system and the reception system. An object of the present invention is to provide an antenna duplexer capable of obtaining characteristics and a wireless terminal using the antenna duplexer.

In order to achieve the above object, the first means of the present invention includes an antenna end matching circuit, a reception surface acoustic wave filter or reception FBAR filter connected to the reception side of the antenna end matching circuit, and a reception surface acoustic wave thereof. A reception system matching circuit connected to a filter or a reception FBAR filter, a transmission surface acoustic wave filter or transmission FBAR filter connected to the transmission side of the antenna end matching circuit, and a connection to the transmission surface acoustic wave filter or transmission FBAR filter In an antenna duplexer equipped with a transmission system matching circuit,
A circuit element constituting the matching circuit is mounted on the uppermost surface of the multilayer substrate, and an element sealing conductive cap is installed on the upper surface of the substrate so as to cover the circuit element.
Except for the uppermost substrate of the multilayer substrate, a part of the other multilayer substrate is notched to form a space, and the surface acoustic wave filter or the reception FBAR filter and the transmission elasticity are formed on the exposed portion of the uppermost substrate. Surface wave filter or transmission FBAR filter is fixed,
Covering the space containing the filter with a conductive cap for sealing the filter,
The mounting surface of the conductive cap for sealing the filter is connected to the ground pattern for the conductive cap installed on the uppermost surface of the multilayer substrate within the multilayer substrate,
An antenna end matching circuit ground pattern connected to the antenna end matching circuit, a transmission system and reception system matching circuit ground pattern connected to the transmission system matching circuit and the reception system matching circuit, and the element sealing conductive The conductive cap and the ground pattern for the conductive cap connected to the conductive cap for sealing the filter are formed separately on the same substrate of the multilayer substrate.

The second means of the present invention is connected to the antenna end matching circuit, the reception surface acoustic wave filter or reception FBAR filter connected to the reception side of the antenna end matching circuit, and the reception surface acoustic wave filter or reception FBAR filter. A reception surface matching circuit, a transmission surface acoustic wave filter or transmission FBAR filter connected to the transmission side of the antenna end matching circuit, and a transmission system matching circuit connected to the transmission surface acoustic wave filter or transmission FBAR filter, In an antenna duplexer equipped with
A circuit element constituting the matching circuit is mounted on the uppermost surface of the multilayer substrate, and an element sealing conductive cap is installed on the upper surface of the substrate so as to cover the circuit element.
Except for the uppermost substrate of the multilayer substrate, a part of the other multilayer substrate is notched to form a space, and the surface acoustic wave filter or the reception FBAR filter and the transmission elasticity are formed on the exposed portion of the uppermost substrate. Surface wave filter or transmission FBAR filter is fixed,
Covering the space containing the filter with a conductive cap for sealing the filter,
The mounting surface of the conductive cap for sealing the filter is connected to the ground pattern for the conductive cap installed on the uppermost surface of the multilayer substrate in the multilayer substrate,
An antenna end matching circuit ground pattern connected to the antenna end matching circuit, a reception system matching circuit ground pattern connected to the reception system matching circuit, and a transmission system matching circuit connected to the transmission system matching circuit Four patterns, a ground pattern, and a conductive cap ground pattern connected to the element sealing conductive cap and the filter sealing conductive cap, are formed separately on the same substrate of the multilayer substrate. It is characterized by being.

According to a third means of the present invention, in the first means or the second means, the antenna end matching circuit ground pattern, the reception system matching circuit ground pattern, the transmission system matching circuit ground pattern, and the conductive cap ground pattern are provided. Or four patterns of the antenna end matching circuit ground pattern, the reception system matching circuit ground pattern, the transmission system matching circuit ground pattern, and the conductive cap ground pattern on each of the plurality of layers of the multilayer substrate. It is formed .

The fourth means of the present invention includes an antenna, an antenna duplexer connected to the antenna, a reception circuit connected to the reception side of the antenna duplexer, and a transmission connected to the transmission side of the antenna duplexer. In the wireless terminal comprising a circuit, the antenna duplexer is the antenna duplexer of the first to third means .

Fifth means of the present invention, in the fourth means, is characterized in that the wireless terminal is a code division multiple access terminal that allows transmission and reception at the same time.

 The present invention is configured as described above, and by separately providing grounding portions, it is possible to prevent deterioration in frequency characteristics due to mutual interference between the antenna, the transmission system, and the reception system. High isolation characteristics can be obtained between the receiving systems.

 Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a circuit block diagram of an antenna duplexer according to the present invention. First, the connection relationship in the package of the antenna duplexer 1 will be described.

 A reception-side phase shift circuit 5 and a reception input-side matching circuit 6-1 are formed between the antenna terminal 3 connected to the antenna 2 and the reception surface acoustic wave filter or reception FBAR filter 9, and the antenna A transmission side phase shift circuit 7 and a transmission output side matching circuit 8-1 are formed between the transmission terminal 3 and the surface acoustic wave filter for transmission or FBAR filter 10 for transmission, and the transmission system and the reception system are connected in parallel. The points 4 are connected in parallel.

 As described above, the antenna duplexer 1 is used at a different frequency when transmitting a transmission signal using a single antenna 2 and when receiving a reception signal, and the transmission system and the reception system are connected to the antenna 2. Connected directly. Therefore, in the case of parallel connection, by maximizing the impedance of the transmission system in the reception frequency band viewed from the parallel connection point 4, and by maximizing the impedance of the reception system in the transmission frequency band viewed from the parallel connection point 4. , It is necessary to control the leakage of each signal.

 Here, the phase shift circuits 5 and 7 have a function of setting an optimum condition in which the impedance of the transmission system becomes a maximum value in the reception frequency band, or an optimum condition in which the impedance of the reception system becomes a maximum value in the transmission frequency band.

 The antenna end matching circuit 13 includes a reception side phase shift circuit 5, a reception input side matching circuit 6-1, a transmission side phase shift circuit 7, and a transmission output side matching circuit 8-1. Are connected to the same grounding pattern via the antenna terminal matching circuit grounding terminal 16.

 A transmission-side phase shift circuit 7 and a transmission output-side matching circuit 8-1 are installed between the antenna terminal 3 and the surface acoustic wave filter for transmission or FBAR filter 10 for transmission. The filter or transmission FBAR filter 10 may have a function that maximizes the impedance of the reception system and a matching circuit function in the transmission frequency band viewed from the parallel connection point 4. In this case, the transmission side phase shift circuit 7 and The transmission output side matching circuit 8-1 may not be provided.

 A reception-side phase shift circuit 5 and a reception input-side matching circuit 6-1 are installed between the antenna terminal 3 and the reception surface acoustic wave filter or reception FBAR filter 9. The filter or the reception FBAR filter 9 may have a matching circuit function in the reception frequency band viewed from the parallel connection point 4, and in this case, the reception input side matching circuit 6-1 may not be provided.

    A reception output side matching circuit 6-2 is connected between the reception system terminal 11 and the reception surface acoustic wave filter or reception FBAR filter 9. The ground of the receiving system matching circuit 14 including the receiving output side matching circuit 6-2 is connected to a pattern provided independently via the receiving system matching circuit ground terminal 17.

    A transmission input side matching circuit 8-2 is connected between the transmission system terminal 12 and the surface acoustic wave filter for transmission or the FBAR filter 10 for transmission. The ground of the transmission system matching circuit 15 including the transmission input side matching circuit 8-2 is connected to a pattern provided independently via the transmission system matching circuit ground terminal 18.

 Next, the structure of a package using a ceramic multilayer substrate will be described. 2A is a top view of the package, FIG. 2B is a cross-sectional view along the line AA ′ in FIG. 2A, and FIG. 2C is along the line BB ′ in FIG. FIG. 2D is a bottom view of the package with the sealing cap removed. In addition, top views of the B layer, the D layer, and the E layer described in the cross-sectional views of FIGS. 2B and 2C are respectively shown in FIGS. 3A, 3B, and 3C. c).

In this embodiment, a multilayer substrate in which five ceramic substrates 48a to 48e are overlapped is used. As shown in FIG. 2 (b), except for the uppermost ceramic substrate 48a among the ceramic substrates 48a to 48e, the substantially central part of the other ceramic substrates 48b to 48e is cut away to expose a part of the ceramic substrate 48a. and, on the substrate surface in a non-conductive adhesive 22 such as the transmitting SAW filter or transmit FBAR filter 10 and the receiving surface acoustic wave filter or the reception FBAR filter 9, for example an epoxy resin on the exposed portion Fix it. The signal pattern and ground pattern on the surface acoustic wave filter or FBAR filter chip are electrically connected to the signal pattern and ground pattern formed on the substrate surface by the bonding wire 26 [FIG. , (D)].

 The surface acoustic wave filter for reception or the FBAR filter for reception 9 and the surface acoustic wave filter for transmission or the FBAR filter for transmission 10 are fixed to the substrate surface with an adhesive 22, so that the surface acoustic wave filter or FBAR filter and its substrate surface are fixed. This has the effect of reducing the capacity with the grounding pattern provided in the circuit, and is effective in reducing loss.

 As shown in FIG. 2B, the sealing cap 29 of the surface acoustic wave filter or FBAR filter 9 or 10 is made of metal or ceramic, and the surface acoustic wave filter or FBAR filter 9 or 10 provided on the multilayer substrate is used. The space 35 to be stored is covered. A mounting surface 34 (see FIG. 2B) of the sealing cap 29 is connected to a metal cap ground pattern 33 provided on the uppermost surface of a multilayer substrate, which will be described later, by a through hole 21 and a castellation 24. [See FIG. 2 (b)].

 As shown in FIG. 2 (c), a lumped constant circuit element 19 (chip capacitor, chip inductor, air core coil, etc.) constituting a phase shift circuit and a matching circuit is mounted on the uppermost surface of the multilayer substrate, and each lumped constant circuit is mounted. The element 19 is connected to the circuit pattern via the soldering land 20. A signal terminal and a ground terminal 25 are provided on the lowermost surface of the multilayer substrate, and are connected to a signal pattern or a ground pattern on the external substrate.

 The top surface circuit pattern of the multilayer substrate, the surface acoustic wave filter for reception or the FBAR filter 9 for reception, the surface acoustic wave filter for transmission or the FBAR filter 10 for transmission, and the terminal 25 on the bottom surface of the multilayer substrate are the through hole 21 and The castellations 24 are electrically connected.

 In the conventional antenna duplexer shown in FIG. 8, a piezoelectric substrate on which a surface acoustic wave filter for transmission and a surface acoustic wave filter for reception are formed is mounted on the chip mounting region 37. The ground potential electrode pad in the transmitting antenna end matching circuit on the uppermost substrate of this package is connected to the terminal 42, and the ground potential electrode pad in the transmission system matching circuit on the uppermost substrate is connected to the terminal 43.

 These terminals 42 and 43 are provided in a transmission system ground potential pattern 38 connected to the ground potential via the transmission system ground terminal 44. The ground potential electrode pad in the receiving antenna end matching circuit on the uppermost substrate is connected to the terminal 40, and the ground potential electrode pad in the receiving system matching circuit on the uppermost substrate is connected to the terminal 41. These terminals 40 and 41 are provided in a reception system ground potential pattern 39 connected to the ground potential via a reception system ground terminal 45.

 In this conventional package, the ground pattern for the transmission system matching circuit and the ground pattern for the reception system matching circuit are separated from each other, and the deterioration of the frequency characteristics due to mutual interference between the transmission system and the reception system in the antenna duplexer is prevented. However, since the ground potentials of the antenna and the transmission system and the antenna and the reception system are the same, sufficient isolation cannot be ensured due to leakage of signals between the antenna and the transmission system and between the antenna and the reception system.

 In this respect, the present invention separates the grounding pattern for each of the antenna end matching circuit, the transmission system matching circuit, and the reception system matching circuit in the pattern of each layer of the multilayer substrate, so that the antenna, the transmission system, and the reception system Degradation of frequency characteristics due to interference can be prevented, and high isolation characteristics can be obtained between the antenna and the transmission and reception systems.

 That is, in each of the B layer (see FIG. 3 (a)), D layer (see FIG. 3 (b)), and E layer (see FIG. 3 (c)) of the multilayer substrate, the antenna end matching circuit ground pattern 30 and The reception system matching circuit ground pattern 31 and the transmission system matching circuit ground pattern 32 are formed separately.

 Further, in order to seal the upper portion of the lumped constant circuit element 19 mounted on the uppermost surface of the multilayer substrate, it is covered with a metallic cap 27 as shown in FIG. As a result, the lumped constant circuit element 19 and the circuit pattern mounted on the uppermost surface of the multilayer substrate can be protected, and grounding of the antenna duplexer is strengthened and the influence of surrounding electromagnetic waves is blocked.

As shown in FIG. 2A, the antenna end matching circuit ground pattern 30, the reception system matching circuit ground pattern 31, and the transmission system matching circuit ground pattern 32 are separately formed on the uppermost surface of the multilayer substrate. As shown in FIG. 2C, the metallic cap 27 is connected to the grounding pattern 33 provided on the uppermost surface of the multilayer substrate by the metallic cap solder 28. Here, the ground pattern 33 for the metallic cap provided on the uppermost surface of the multilayer substrate is separated from the ground pattern 30 for the antenna end matching circuit, the ground pattern 31 for the reception system matching circuit, and the ground pattern 32 for the transmission system matching circuit. And grounded via the mounting surface 34 of the surface acoustic wave filter or FBAR filter sealing cap 29.

 FIG. 4 is a cross-sectional view of a package when surface acoustic wave filters or FBAR filters 9 and 10 are mounted by means of bumps 23 using flip-chip bonding, and the clearance required for bonding wire connection can be eliminated. , It is effective for thinning the package.

 Embodiments relating to the grounding pattern of other antenna duplexers are shown in FIGS.

 FIG. 5 is divided into the antenna end matching circuit ground pattern 30 and the transmission system and reception system matching circuit ground pattern 47. The transmission system and reception system matching circuit ground pattern 47 includes the transmission input side and reception output side matching circuit. The antenna duplexer is characterized in that it is connected to the ground potential via the ground terminal 46, and is effective with respect to the isolation characteristics between the antenna and the transmission system and between the antenna and the reception system.

 FIG. 6 shows an antenna duplexer in which ground patterns 30 for an antenna end matching circuit, a ground pattern 31 for a transmission system matching circuit, and a ground pattern 32 for a reception system matching circuit are separately provided. It is effective with respect to the isolation characteristics of the antenna, transmission system, and reception system.

 7 is separated into a ground pattern 30 for an antenna end matching circuit and a ground pattern 47 for a transmission system and a reception system matching circuit. The ground pattern 47 for a transmission system and a reception system matching circuit is divided into a transmission input side and a reception output side matching circuit. It is connected to the ground potential via the ground terminal 46 for use.

 Further, the ground pattern 33 for the metallic cap that covers the uppermost surface of the multilayer substrate is provided separately from the ground pattern 30 for the antenna end matching circuit and the ground pattern 47 for the transmission system and the reception system matching circuit. The antenna duplexer is characterized in that it is grounded via the mounting surface 34 of the filter sealing cap, and is effective in preventing a signal from leaking through the metallic cap 27.

    In the present invention, the realization of high isolation characteristics is particularly advantageous for application to a CDMA antenna duplexer.

 In the above embodiment, a metallic cap is used as the conductive cap. However, the present invention is not limited to this. For example, a cap made of a molded product of a conductive resin, or a molded product of a synthetic resin subjected to metal plating. It is also possible to use a cap made of or the like.

It is a circuit block diagram of the antenna sharing device which concerns on the Example of this invention. It is a top view of the package used for the Example of this invention. It is sectional drawing on the A-A 'line of Fig.2 (a). It is a top view of the package. It is sectional drawing on the B-B 'line of Fig.2 (a). It is a top view of B layer, D layer, and E layer of a package substrate used for the package. It is sectional drawing of the package which mounts the surface acoustic wave filter or FBAR filter which shows the other example of this invention by bump. It is a top view of a package substrate showing still another example of the present invention. It is a top view of a package substrate showing still another example of the present invention. It is a top view of a package substrate showing still another example of the present invention. It is a top view of the package board | substrate of the antenna sharing device proposed conventionally. It is a block diagram for demonstrating a CDMA system.

Explanation of symbols

1 ... Antenna duplexer, 2 ... Antenna, 3 ... Antenna terminal, 4 ... Parallel connection point, 5 ... Reception phase shift circuit, 6-1 ... Reception input side matching Circuit, 6-2 ... Reception output side matching circuit, 7 ... Transmission side phase shift circuit, 8-1 ... Transmission output side matching circuit, 8-2 ... Transmission input side matching circuit, ..Surface acoustic wave filter for reception or FBAR filter for reception, 10 ... surface acoustic wave filter for transmission or FBAR filter for transmission, 11 ... reception system terminal, 12 ... transmission system terminal, 13 ... Antenna end matching circuit, 14 ... Receiving system matching circuit, 15 ... Transmitting system matching circuit, 16 ... Ground terminal for antenna end matching circuit, 17 ... Ground terminal for receiving system matching circuit, 18 ...・ Ground terminal for transmitter matching circuit, 19 ... Lumped constant circuit element, 20 ... Soldering land, 21 ... Through hole, 22 ... Non-conductive Adhesive, 23 ... Bump, 24 ... Castellation, 25 ... Ground terminal, 26 ... Bonding wire, 27 ... Metal cap, 28 ... Solder for metal cap, 29・ ・ ・ Surface acoustic wave filter or FBAR filter sealing cap, 30 ・ ・ ・ Grounding pattern for antenna end matching circuit, 31 ・ ・ ・ Grounding pattern for receiving system matching circuit, 32 ・ ・ ・ Grounding pattern for transmission system matching circuit , 33 ... Ground pattern for metallic cap, 34 ... Mounting surface of the surface acoustic wave filter or FBAR filter sealing cap, 35 ... Cavity for storing surface acoustic wave filter or FBAR filter, 36 ... Multilayer package substrate, 37 ... chip mounting area, 38 ... transmitting system ground potential pattern, 39 ... receiving system ground potential pattern, 40 to 43 ... terminal, 44 ... transmitting system ground terminal, 45 ... Receiving system ground terminal, 46 And transmitting the input side and the receiving output matching circuit ground terminal, the ground pattern 47 ... transmitting and receiving systems matching circuit, 48a - 48e ... ceramic substrate.

Claims (5)

An antenna end matching circuit, a reception surface acoustic wave filter or reception FBAR filter connected to the reception side of the antenna end matching circuit, a reception system matching circuit connected to the reception surface acoustic wave filter or reception FBAR filter, and In an antenna duplexer comprising a transmission surface acoustic wave filter or transmission FBAR filter connected to the transmission side of an antenna end matching circuit, and a transmission system matching circuit connected to the transmission surface acoustic wave filter or transmission FBAR filter,
A circuit element constituting the matching circuit is mounted on the uppermost surface of the multilayer substrate, and an element sealing conductive cap is installed on the upper surface of the substrate so as to cover the circuit element.
Except for the uppermost substrate of the multilayer substrate, a part of the other multilayer substrate is notched to form a space, and the surface acoustic wave filter or the reception FBAR filter and the transmission elasticity are formed on the exposed portion of the uppermost substrate. Surface wave filter or transmission FBAR filter is fixed,
Covering the space containing the filter with a conductive cap for sealing the filter,
The mounting surface of the conductive cap for sealing the filter is connected to the ground pattern for the conductive cap installed on the uppermost surface of the multilayer substrate within the multilayer substrate,
An antenna end matching circuit ground pattern connected to the antenna end matching circuit, a transmission system and reception system matching circuit ground pattern connected to the transmission system matching circuit and the reception system matching circuit, and the element sealing conductive An antenna duplexer, wherein three patterns of a conductive cap and a ground pattern for a conductive cap connected to a conductive cap for sealing a filter are formed separately on the same substrate of the multilayer substrate. An antenna end matching circuit, a reception surface acoustic wave filter or reception FBAR filter connected to the reception side of the antenna end matching circuit, a reception system matching circuit connected to the reception surface acoustic wave filter or reception FBAR filter, and In an antenna duplexer comprising a transmission surface acoustic wave filter or transmission FBAR filter connected to the transmitting side of an antenna end matching circuit, and a transmission system matching circuit connected to the transmission surface acoustic wave filter or transmission FBAR filter,
A circuit element constituting the matching circuit is mounted on the uppermost surface of the multilayer substrate, and an element sealing conductive cap is installed on the upper surface of the substrate so as to cover the circuit element.
Except for the uppermost substrate of the multilayer substrate, a part of the other multilayer substrate is notched to form a space, and the surface acoustic wave filter or the reception FBAR filter and the transmission elasticity are formed on the exposed portion of the uppermost substrate. Surface wave filter or transmission FBAR filter is fixed,
Covering the space containing the filter with a conductive cap for sealing the filter,
The mounting surface of the conductive cap for sealing the filter is connected to the ground pattern for the conductive cap installed on the uppermost surface of the multilayer substrate within the multilayer substrate,
An antenna end matching circuit ground pattern connected to the antenna end matching circuit, a reception system matching circuit ground pattern connected to the reception system matching circuit, and a transmission system matching circuit connected to the transmission system matching circuit Four patterns, a ground pattern, and a conductive cap ground pattern connected to the element sealing conductive cap and the filter sealing conductive cap, are formed separately on the same substrate of the multilayer substrate. An antenna duplexer characterized by having The antenna duplexer according to claim 1 or 2,
The antenna end matching circuit ground pattern, the receiving system matching circuit ground pattern and the transmission system matching circuit ground pattern and the conductive cap ground pattern, or the antenna end matching circuit ground pattern and the receiving system matching circuit ground pattern. And an antenna duplexer in which four patterns of a transmission system matching circuit ground pattern and a conductive cap ground pattern are formed on a plurality of layers of the multilayer substrate, respectively . In a wireless terminal comprising an antenna, an antenna duplexer connected to the antenna, a reception circuit connected to the reception side of the antenna duplexer, and a transmission circuit connected to the transmission side of the antenna duplexer, 4. The wireless terminal according to claim 1, wherein the antenna duplexer is the antenna duplexer according to claim 1. 5. The wireless terminal according to claim 4, wherein the wireless terminal is a code division multiple access terminal capable of transmitting and receiving simultaneously.

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