WO2010087304A1

WO2010087304A1 - Duplexer module

Info

Publication number: WO2010087304A1
Application number: PCT/JP2010/050900
Authority: WO
Inventors: 降谷孝治
Original assignee: 株式会社村田製作所
Priority date: 2009-01-28
Filing date: 2010-01-25
Publication date: 2010-08-05

Abstract

Provided is a duplexer module wherein deterioration of isolation between signal lines is suppressed, even when the duplexer module has reduced sizes, and communication performance is improved. A duplexer module (1) has a transmission line (5), a reception line (4) and an antenna line (3) connected therein, and is provided with a transmission filter (Tx), a reception filter (Rx) and a multilayer substrate (2). The transmission filter (Tx) is inserted into the transmission line (5) and passes through transmitting signals. The reception filter (Rx) is inserted into the reception line (4) and passes through receiving signals. In the multilayer substrate (2), a surface electrode (21) having the transmission filter (Tx) mounted thereon is formed on the top surface, and a surface electrode (21) having the reception filter (Rx) mounted thereon is formed on the bottom surface of a recessed section (23).

Description

Duplexer module

The present invention relates to a duplexer module in which a duplexer is provided on a printed board or a multilayer board.

• A duplexer module that separates transmission and reception signals is used in the front-end part of mobile phones and the like. Generally, a duplexer module is mounted on a mounted device by mounting electrodes provided on a mounting surface of a module substrate. Also, the discrete circuit element is mounted on the surface electrode provided on the chip mounting surface facing the mounting surface of the module substrate. A signal line connecting the mounting electrode and the surface electrode is provided with a transmission filter and a reception filter.

A plurality of duplexers having different signal frequency bands may be employed in the multiband front end unit (see, for example, Patent Document 1). In this duplexer module, the transmission filter and the reception filter that constitute each duplexer are configured as an integrated discrete circuit element. The discrete circuit elements of each duplexer are arranged adjacent to each other with the direction in which the surface electrode for input and the surface electrode for output are arranged in the same direction.

JP 2005-123909 A

Due to the progress of miniaturization of duplexer modules, it has become difficult to arrange signal lines such as transmission lines through which transmission signals flow and reception lines through which reception signals flow with sufficient intervals. In particular, in the above-described duplexer module supporting multiband, it may be necessary to arrange the discrete circuit elements of each duplexer in parallel so that signal lines from each of them partially intersect. For this reason, degradation of isolation between signal lines is likely to occur, and communication performance such as reception sensitivity is lowered, which causes a problem.

Therefore, an object of the present invention is to provide a duplexer module having a configuration in which the isolation between signal lines and the deterioration of communication performance are suppressed and the size can be reduced.

The present invention is a duplexer module in which a transmission line, a reception line, and an antenna line are connected, and includes a transmission filter, a reception filter, and a module substrate. The transmission line transmits a transmission signal. The reception line transmits a reception signal. The antenna line transmits a transmission signal and a reception signal. The transmission filter is inserted in the transmission line. The reception filter is inserted in the reception line. The module substrate has a surface electrode on which a transmission filter is mounted on a first main surface, and a surface electrode on which a reception filter is mounted on a second main surface opposite to the first main surface.

In this configuration, the transmission filter and the reception filter are each configured as separate discrete circuit elements and arranged on both main surfaces of the module substrate. As a result, the transmission line and the reception line can be arranged sufficiently apart from each other, the isolation between the transmission line and the reception line can be improved, and communication performance such as reception sensitivity can be improved. Further, since both filters are provided on different main surfaces, the area size of the module substrate can be reduced, and the degree of freedom of the wiring layout of each signal line is improved.

It is preferable that the module substrate includes a ground electrode parallel to the first and second main surfaces, and the ground electrode is disposed between the transmission filter and the reception filter. In this configuration, the ground electrode is interposed at a position partitioning between the transmission filter and the reception filter, and both the filters can be electrically separated by the ground potential. Thereby, the isolation between a transmission line and a receiving line can be improved.

The ground electrode is preferably disposed so as to cover the transmission filter and the reception filter when the module substrate is viewed in plan from the normal direction of the substrate. Thereby, the isolation between the circuit elements mounted on both main surfaces can be improved.

The module substrate is preferably arranged such that the transmission line and the reception line are arranged at different positions in the normal direction of the substrate. In this configuration, since both lines do not directly face each other with the module substrate interposed therebetween, the isolation between the transmission line and the reception line can be improved.

The duplexer module preferably has a power amplifier for amplifying a transmission signal mounted on the first main surface of the module substrate. In this configuration, the power amplifier inserted into the transmission line and the transmission filter of the duplexer are both provided on the first main surface of the module substrate, so that the wiring between both circuit elements can be shortened and wiring is facilitated. To do. In addition, since the power amplifier and the reception filter are mounted on different main surfaces, the isolation between the transmission line and the reception line can be improved.

In the duplexer module, it is preferable that a switch for switching the line connection in the antenna line or the reception line is mounted on the second main surface of the module substrate. In this configuration, by providing both the switch inserted into the antenna line or the reception line and the reception filter of the duplexer on the second main surface of the module substrate, the wiring between the two circuit elements can be shortened. Make it easier. In addition, since the switch and the transmission filter are mounted on different main surfaces, the isolation between the transmission line and the reception line can be improved. Furthermore, the isolation between the power supply voltage of the switch decoder or the like and the transmission signal can be improved, and the occurrence of high frequency distortion can be suppressed.

The duplexer module may have a configuration including a plurality of transmission lines, reception lines, and antenna lines. In this case, it is preferable that the plurality of transmission filters provided in the plurality of transmission lines are configured by one discrete circuit element, and the plurality of reception filters provided in the plurality of reception lines are configured by one discrete circuit element. With this configuration, it is possible to reduce the manufacturing cost and simplify the manufacturing process by suppressing the number of discrete circuit elements mounted on the module substrate.

The module substrate is preferably provided with a discrete circuit element having a recess on the first main surface and / or the second main surface, and a transmission filter or a reception filter formed on the bottom surface of the recess. In this configuration, the discrete circuit element can be prevented from protruding from the main surface of the module substrate provided with the recess.

The ground electrode is preferably arranged so as to cover the bottom surface of the recess when the module substrate is viewed in plan from the substrate normal direction. Thereby, the isolation between the circuit element mounted on one main surface and the circuit element mounted on the recess of the other main surface can be improved.

It is preferable that the module substrate has a built-in matching circuit that performs impedance matching between discrete circuit elements. With this configuration, the degree of freedom of the wiring layout between the matching circuit and the discrete circuit element is improved, and the wiring can be shortened. Therefore, phase adjustment for impedance matching in the matching circuit is facilitated.

According to the present invention, the transmission filter and the reception filter are arranged on both main surfaces of the module substrate as separate circuit elements, respectively, so that the transmission line and the reception line can be easily routed. This makes it possible to arrange both lines sufficiently apart, and even if the duplexer module is downsized, the duplexer module can be reduced by suppressing the degradation of isolation between the transmission line and the reception line and the degradation of communication performance. Can be downsized.

FIG. 3 is a diagram illustrating a configuration example of a duplexer module according to the first embodiment of the present invention. It is a figure explaining the structural example of the duplexer module which concerns on the 2nd Embodiment of this invention. It is a figure explaining the structural example of the duplexer module which concerns on the 3rd Embodiment of this invention.

FIG. 1 is a diagram illustrating a configuration example of a duplexer module according to a first embodiment of the present invention. 1A is a schematic equivalent circuit diagram of the duplexer module 1, and FIG. 1B is a side sectional view of the duplexer module 1.

The equivalent circuit shown in FIG. 1A of the duplexer module 1 includes an antenna line 3, a reception line 4, a transmission line 5, a transmission filter Tx, a reception filter Rx, and

matching circuits

7, 8, and 9.

The antenna line 3, the reception line 4 and the transmission line 5 are connected by a matching circuit 7. The matching circuit 7 performs impedance matching between the lines. The antenna line 3 includes an antenna port ANT as an external connection port, and connects the matching circuit 7 and the antenna port ANT, and transmits a transmission signal and a reception signal. The reception line 4 includes a reception port RX as an external connection port, and connects the matching circuit 7 and the reception port RX. The transmission line 5 includes a transmission port TX as an external connection port, and connects the matching circuit 7 and the transmission port TX. The transmission filter Tx is inserted in the transmission line 5 and passes a transmission signal of a predetermined frequency band. The matching circuit 9 is inserted in the transmission line 5 and matches the impedance of the transmission port TX to 50Ω. The reception filter Rx is inserted in the reception line 4 and passes a reception signal in a predetermined frequency band. The matching circuit 8 is inserted in the reception line 4 and matches the impedance of the reception port RX to 50Ω. The matching

circuits

7, 8 and 9 can also adjust the phase of the transmission filter Tx and the reception filter Rx by changing the line length and line width.

As shown in FIG. 1B, the duplexer module 1 includes a multilayer substrate 2 corresponding to the module substrate of the present invention. The multilayer substrate 2 is formed by laminating a plurality of substrates, and the top surface, which is the first main surface, includes a surface electrode 21 on which a discrete circuit element is mounted. The bottom surface that is the second main surface of the multilayer substrate 2 is a module mounting surface, and includes a plurality of mounting electrodes 22 that serve as external connection ports of the duplexer module 1. A recess 23 is provided on the module mounting surface, and a surface electrode 21 on which a discrete circuit element is mounted is also provided on the bottom surface of the recess 23. The surface electrodes 21 or between the surface electrode 21 and the mounting electrode 22 are connected by a pattern electrode or via electrode provided on the substrate surface of the multilayer substrate 2 or inside the substrate. Between the layers of the multilayer substrate 2, pattern electrodes to be the ground electrode 24 and the

matching circuits

7, 8, 9 are provided.

The transmission filter Tx and the reception filter Rx are discrete components of a filter using surface acoustic wave resonators each provided with an IDT electrode. The transmission filter Tx is mounted on the top surface, which is the first main surface of the multilayer substrate 2. The reception filter Rx is mounted on the bottom surface of the recess 23 which is the second main surface of the multilayer substrate 2. The transmission filter Tx and the reception filter Rx are molded with respect to the multilayer substrate 2 with a molding resin 6. The mold resin 6 may not be provided.

Here, the transmission filter Tx and the reception filter Rx are respectively mounted on both main surfaces of the multilayer substrate 2 as discrete circuit elements. As a result, the transmission line 5 and the reception line 4 can be arranged sufficiently apart from each other, and the area size of the multilayer substrate 2 can be reduced. Therefore, the degree of freedom of the wiring layout of the transmission line 5 and the reception line 4 is improved. Further, the ground electrode 24 is interposed at a position that partitions between the surface electrode 21 on which the transmission filter Tx is mounted and the surface electrode 21 on which the reception filter Rx is mounted. As a result, the transmission filter Tx and the reception filter Rx are separated by the ground potential. Further, as shown in FIG. 1B, the ground electrode 24 is arranged in a larger area than the area where the transmission filter Tx and the reception filter Rx are arranged, so that the transmission line 5 and the reception line 4 are arranged. Isolation can be further improved. Further, the pattern electrode of the matching circuit 8 and the pattern electrode of the matching circuit 9 are arranged so as not to face each other in the normal direction of the substrate. Thereby, both pattern electrodes do not face each other directly across the multilayer substrate 2. Therefore, in the duplexer module 1 of the present embodiment, the isolation between the transmission line 5 and the reception line 4 can be further improved.

In the present embodiment, the configuration example in which the ground electrode 24 is provided between the layers of the multilayer substrate 2 is shown, but the ground electrode 24 and the

matching circuits

8 and 9 are not necessarily required. Isolation can be improved without providing the ground electrode 24 by interposing a pattern electrode such as a matching circuit at a position separating the discrete circuit elements on both main surfaces. The transmission line 5 and the reception line 4 are connected via the matching circuit 7. However, a cutout or an opening may be provided in the ground electrode 24 in order to connect both. With such a structure, the distance between the connecting portions can be shortened, and the module can be miniaturized.

Also, the matching

circuits

7, 8, and 9 need not be built in the duplexer module 1. In that case, it is preferable to provide a circuit equivalent to the

matching circuits

8 and 9 in a transmission circuit, a reception circuit, an antenna and the like connected to the outside of the module.

Further, another circuit element may be inserted into the transmission line or the reception line. In that case, discrete circuit elements inserted into the transmission line are mounted on the top surface side of the multilayer substrate 2, and discrete circuit elements inserted into the reception line are mounted on the bottom surface side of the multilayer substrate 2. It is preferable because deterioration of isolation due to the element can be suppressed.

Alternatively, the discrete circuit element inserted into the transmission line may be arranged on the bottom surface side of the multilayer substrate 2, and the discrete circuit element inserted into the reception line may be arranged on the top surface side of the multilayer substrate 2.

The present invention can be suitably implemented by disposing the discrete circuit element inserted into the transmission line on a substrate main surface different from the discrete circuit element inserted into the reception line or the discrete circuit element inserted into the antenna line.

FIG. 2 is a diagram illustrating a configuration example of a duplexer module according to the second embodiment of the present invention. FIG. 2A is a schematic equivalent circuit diagram of the duplexer module 11 according to the embodiment, and FIG. 2B is a side cross-sectional view of the duplexer module 11. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

2A of the duplexer module 11 includes an antenna line 3, a reception line 4, a transmission line 5, a transmission filter Tx, a reception filter Rx, matching

circuits

7, 8, and 9, and a power amplifier PA. The power amplifier PA is inserted between the transmission port TX in the transmission line 5 and the matching circuit 9 and amplifies the transmission signal. As shown in FIG. 2B, the power amplifier PA is a discrete circuit element and is mounted on the surface electrode 21 provided on the top surface of the multilayer substrate 2.

Here, the power amplifier PA is mounted on the top surface of the same multilayer substrate 2 as the transmission filter Tx as a discrete circuit element. As a result, the discrete circuit element of the power amplifier PA inserted into the transmission line 5 and the discrete circuit element inserted into the reception line 4 can be arranged sufficiently apart. The ground electrode 24 is also interposed at a position that partitions the surface electrode 21 on which the power amplifier PA is mounted and the surface electrode 21 on which the reception filter Rx is mounted. Therefore, in the duplexer module 11 of the present embodiment, the isolation between the transmission line 5 and the reception line 4 can be improved even when the power amplifier PA is provided.

A matching circuit may be separately inserted between the transmission port TX and the power amplifier PA in the transmission line 5, or the duplexer module 11 may be configured by omitting the matching circuit 8 in the reception line 4. good.

FIG. 3 is a diagram illustrating a configuration example of the duplexer module according to the embodiment of the present invention. FIG. 3A is a schematic equivalent circuit diagram of the duplexer module 31 according to the embodiment, and FIG. 3B is a side sectional view of the duplexer module 31.

The duplexer module 31 of this embodiment constitutes a triplexer type duplexer that shares an antenna port ANT with three communication systems having different target frequency bands.

The equivalent circuit shown in FIG. 3A of the duplexer module 31 includes antenna switching lines 3A to 3C, antenna shared lines 3D, reception lines 4A to 4C, transmission lines 5A to 5C, a switch SW, and three duplexers DHU. The antenna common line 3D and the antenna switching lines 3A to 3C are connected by a switch SW. The switch SW selects any one of the antenna switching lines 3A to 3C and connects it to the antenna sharing line 3D. The antenna sharing line 3D includes an antenna port ANT as an external connection port, and transmits transmission signals and reception signals of the three communication systems. The antenna switching lines 3A to 3C transmit a transmission signal and a reception signal of any communication system. The duplexer DHU includes a transmission filter and a reception filter, and separates a transmission signal and a reception signal of a target communication system into reception lines 4A to 4C and transmission lines 5A to 5C. As shown in FIG. 1B, the switch SW is a discrete circuit element and is mounted on the surface electrode 21 formed on the bottom surface of the recess 23. The transmission filters in the three duplexers DHU are configured as a transmission filter chip 3Tx that is an integrated discrete circuit element, and the reception filters in the three duplexers DHU are configured as a reception filter chip 3Rx that is an integrated discrete circuit element.

Here, the switch SW is mounted as a discrete circuit element on the bottom of the same recess 23 as the reception filter chip 3Rx. As a result, the transmission line and the reception line in each duplexer DHU can be arranged sufficiently apart from each other. The ground electrode 24 is also interposed at a position that partitions the surface electrode 21 on which the switch SW is mounted and the surface electrode 21 on which the transmission filter chip 3Tx is mounted. Therefore, in the duplexer module 31 of this embodiment, even if it is the structure provided with switch SW, the isolation between a transmission line and a receiving line can be improved. It is preferable that a matching circuit is appropriately inserted in the signal line.

As long as the present invention is a module that constitutes a duplexer, it is possible to adopt a configuration other than the circuit configuration and cross-sectional configuration shown in each of the above-described embodiments, and at least the transmission filter and the reception filter are arranged separately on both main surfaces of the substrate. By doing so, the isolation of the duplexer can be improved.

DESCRIPTION OF

SYMBOLS

1,11,31 ... Duplexer module 2 ... Multilayer board 3 ... Antenna line 3D ... Antenna common line 3A-3C ... Antenna switching line 4 ... Reception line 5 ... Transmission line 6 ... Mold resin 7 ...

Phase adjustment circuit

8, 9 ... Matching Circuit 21 ... Surface electrode 22 ... Mounting electrode 23 ... Recess 24 ... Ground electrode DHU ... Duplexer PA ... Power amplifier Rx ... Reception filter Tx ... Transmission filter 3Rx ... Reception filter chip 3Tx ... Transmission filter chip SW ... Switch

Claims

A duplexer module connecting a transmission line for transmitting a transmission signal, a reception line for transmitting a reception signal, and an antenna line for transmitting the transmission signal and the reception signal;
A transmission filter inserted in the transmission line;
A reception filter inserted in the reception line;
A module substrate in which a surface electrode for mounting the transmission filter is formed on a first main surface, and a surface electrode for mounting the reception filter is formed on a second main surface opposite to the first main surface;
Duplexer module with
The duplexer module according to claim 1, wherein the module substrate includes a ground electrode parallel to the first and second main surfaces, and the ground electrode is disposed between the transmission filter and the reception filter. .
The duplexer module according to claim 2, wherein the ground electrode is disposed so as to cover the transmission filter and the reception filter when the module substrate is viewed in plan from the normal direction of the substrate.
The duplexer module according to any one of claims 1 to 3, wherein the module substrate is configured such that an electrode serving as the transmission line and an electrode serving as the reception line are arranged at different positions in the normal direction of the substrate.
5. The duplexer module according to claim 1, wherein a power amplifier that amplifies the transmission signal is mounted on the first main surface of the module substrate.
The duplexer module according to any one of claims 1 to 5, wherein a switch for switching a line connection in the antenna line or the reception line is mounted on a second main surface of the module substrate.
A duplexer module comprising a plurality of sets of the transmission line, the reception line, and the antenna line,
The plurality of transmission filters provided in the plurality of transmission lines are configured by one discrete circuit element, and the plurality of reception filters provided in the plurality of reception lines are configured by one discrete circuit element. The duplexer module according to claim 6.
The module substrate includes a recess on the first main surface and / or the second main surface, and a discrete circuit element on which the transmission filter or the reception filter is configured is mounted on a bottom surface of the recess. Item 8. The duplexer module according to any one of Items 1 to 7.
The duplexer module according to claim 8, wherein the ground electrode is disposed so as to cover a bottom surface of the recess when the module substrate is viewed in plan from the normal direction of the substrate.
The duplexer module according to any one of claims 1 to 7, wherein the module substrate includes a matching circuit for impedance matching between the discrete circuit elements.