JP4122252B2 - High frequency switch module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency switch module that can be used in portable radios such as portable radios and automobile phones in the microwave field.
[0002]
[Prior art]
As an example of this type of high frequency switch module, there is one using a GaAs switch element. FIG. 5 shows a circuit configuration of a dual-band front end module, and the antenna ANT, GSM and DCS are branched or coupled. A demultiplexer DIP, a GaAs switch element SW1 incorporated in a GSM transmission circuit for switching between a GSM transmission signal and a reception signal, and a GaAs switch incorporated in a DCS transmission circuit for switching between a DCS transmission signal and a reception signal. It has element SW2. The duplexer DIP basically includes an inductor element and a capacitor. For example, the GSM GaAs switch element SW1 connects the antenna side terminal and the GSM transmission circuit side Tx during transmission, and connects the antenna side terminal and the GSM reception circuit side Rx during reception. (Refer nonpatent literature 1).
[0003]
Usually, a GaAs switch is mounted on a multilayer substrate, and a diplexer, a low-pass filter, and the like are layered in the multilayer substrate. A pad to which the terminal of the GaAs switch element is connected is provided on the surface of the multilayer substrate, and the pad is an external circuit formed on the side surface or the back surface of the multilayer substrate via a wiring (that is, a routing line) in the multilayer substrate. Connected to the connection terminal.
[0004]
[Non-Patent Document 1]
Magazine IEEE Radio Frequency Integrated Circuits System Vol. 2001 PP213〜216
[0005]
Since the multilayer substrate is mounted on the PCB, the position or location of the external circuit connection terminals formed on the side surface or the back surface of the multilayer substrate is determined by the terminal arrangement of the mounted PCB. By the way, this type of component is generally supplied from a specialized manufacturer and is actually manufactured according to the manufacturer's own standard from the viewpoint of manufacturing cost and design. That is, each terminal of the pad and the external circuit connection terminal formed on the side surface or the back surface of the multilayer substrate often do not correspond in position. Therefore, each terminal of the pad and the external circuit connection terminal are connected using wiring.
[0006]
[Problems to be solved by the invention]
However, as shown in FIG. 6, for example, when the positions of the external circuit connection terminal 900 HzRx and the terminal 900 HzRx of the GaAs switch mounting pad to be connected to the external circuit connection terminal are separated from each other, these terminals are separated by the shortest distance. When connected, the wiring is located below the GaAs switch element, which causes problems such as mutual interference and stray capacitance, which affects the electrical characteristics. Therefore, in the GaAs switch element-mounted high-frequency switch module, the wiring is not located below the GaAs switch element depending on the arrangement of the GaAs switch element terminal or the GaAs switch element mounting pad and the external circuit connection terminal of the high-frequency switch module. As described above, further, a long wiring W is required in the multilayer substrate so as to avoid interference (coupling) with another circuit element that is layered on the multilayer substrate. However, such a long wiring leads to a large transmission loss.
[0007]
Therefore, an object of the present invention is to provide a high-frequency switch module that solves the above-described problems and that can avoid an increase in transmission loss without affecting the electrical characteristics.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a high-frequency switch module according to the present invention provides:
A multilayer substrate;
An external circuit connection terminal formed on the side surface or the back surface of the multilayer substrate;
A GaAs switch element mounting pad formed on the surface of the multilayer substrate;
A GaAs switch element mounted on the multilayer substrate via the GaAs switch element mounting pad;
Another circuit element other than the GaAs switch element formed in the multilayer substrate;
At least two ground electrodes formed in positions spaced apart from each other in the multilayer substrate;
Formed in a region of the multilayer substrate sandwiched between the ground electrodes that are spaced apart in the vertical direction in the multilayer substrate, wiring for electrically connecting the GaAs switch element mounting pad and the external circuit connection terminal;
Have
Sandwiched by the multilayer substrate other than the region in the ground electrode, it is characterized in that a said further circuit elements.
[0009]
Preferably, the wiring for electrically connecting the GaAs switch element mounting pad and the external circuit connection terminal at the shortest distance and the ground electrodes located above and below the wiring can be separated by at least 30 μm or more.
[0010]
More preferably, the another circuit element may be a low-pass filter through which a transmission signal passes.
[0011]
More preferably, the another circuit element may be a branching circuit through which a reception signal or a transmission signal passes.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 schematically shows a high-frequency switch module according to an embodiment of the present invention. The illustrated high-frequency switch module is formed on a multilayer substrate 7 composed of a plurality of dielectric substrates 1, 2, 3, 4, 5, 6. A GaAs switch element mounting pad 8 is formed on the uppermost dielectric substrate 6. Each terminal of the GaAs switch element 9 is electrically connected to the GaAs switch element mounting pad 8. It is installed.
[0013]
Here, an example of the configuration of a switch circuit configured for dual band using a GaAs switch element in a high frequency switch module will be described. As shown in FIG. 2, branching or coupling of an antenna ANT, EGSM, and DCS is performed. The branching filter DIP, the antenna terminal ANT of the multilayer substrate, the transmission circuit terminal Tx1 (EGSM) for EGSM, the reception circuit terminal Rx1 (EGSM), the transmission circuit terminal Tx2 (DCS) for DCS, and the reception circuit terminal Rx2 (DCS) And a GaAs switch element unit 9 connected to (). GaAs switching element is incorporated into EGSM for transmission circuits, a GaAs switching element 9 A for switching between transmit and receive signals of the EGSM, incorporated into the DCS transmission circuit, switches the transmission signal and the reception signal of the DCS And a GaAs switch element portion 9B. The duplexer DIP basically includes an inductor element and a capacitor. The GaAs switch element portions 9A and 9B are configured as single pole double throw type (SPDT) GaAs switch elements.
[0014]
The EGSM GaAs switch element portion 9A is connected to the antenna terminal ANT of the multilayer substrate, the transmission circuit terminal Tx1 (EGSM) for EGSM, and the reception circuit terminal Rx1 (EGSM). During transmission, the antenna side terminal and the transmission circuit terminal for EGSM are used. Tx1 (EGSM) is connected, and at the time of reception, the antenna side terminal and the EGSM receiving circuit terminal Rx1 (EGSM) are connected. The DCS GaAs switch element section 9B is connected to the antenna terminal ANT of the multilayer substrate, the DCS transmission circuit terminal Tx2 (DCS), and the reception circuit terminal Rx2 (DCS). At the time of transmission, the antenna side terminal and the DCS transmission circuit terminal Tx2 (DCS) is connected, and at the time of reception, the antenna side terminal and DCS receiving circuit terminal Rx2 (DCS) are connected.
[0015]
The first terminal 9a of the GaAs switch element portion 9A is connected to the EGSM receiving circuit terminal Rx1 (EGSM) of the multilayer substrate, and the second terminal 9b is connected to the transmitting circuit terminal Tx1 (EGSM) of the multilayer substrate via the low pass filter LPF1. The common terminal 9c of the GaAs switch element portion 9A is connected to the antenna terminal ANT of the multilayer substrate via the duplexer DIP. Further, driving power supply terminals T1 and T2 are connected to the GaAs switch element portion 9A. Similarly, the first terminal 9d of the GaAs switch element 9B is connected to the DCS reception circuit terminal Rx2 (DCS) of the multilayer substrate, and the second terminal 9e is connected to the transmission circuit terminal Tx2 (DCS) of the multilayer substrate via the low-pass filter LPF2. The common terminal 9f of the GaAs switch element portion 9B is connected to the antenna terminal ANT of the multilayer substrate via the duplexer DIP. Further, operation control terminals T3 and T4 are connected to the GaAs switch element portion 9B.
[0016]
As shown in FIG. 3, the GaAs switch element 9 includes a terminal 9a connected to the EGSM reception circuit terminal Rx1 (EGSM) of the multilayer substrate, and a transmission circuit terminal Tx1 (EGSM) of the multilayer substrate via the low-pass filter LPF1. A terminal 9b connected to the antenna terminal ANT of the multilayer board via the duplexer DIP, a terminal 9d connected to the DCS receiving circuit terminal Rx2 (DCS) of the multilayer board, and a low-pass filter LPF2. A terminal 9e connected to the transmission circuit terminal Tx2 (DCS) of the multilayer board via the terminal, a terminal 9f connected to the antenna terminal ANT of the multilayer board via the duplexer DIP, the drive power supply terminals T1 and T2, and the operation Pads for the control terminals T3 and T4 are formed.
[0017]
In the multilayer substrate 7, as shown in FIG. 1, the corresponding terminals of the GaAs switch element mounting pad 8 and the external circuit connection terminal (not shown) formed on the side surface of the multilayer substrate 7 are electrically connected to each other. The wiring 11 to be connected is arranged, and the ground electrodes 12 and 13 are arranged with the wiring 11 sandwiched up and down. That is, the wiring 11 is arranged in a region sandwiched between the ground electrodes 12 and 13. Further, as shown in FIG. 4, the wiring 11 has a substantially straight line between corresponding terminals of the GaAs switch element mounting pad 8 and an external circuit connection terminal (not shown) formed on the side surface of the multilayer substrate 7. They are arranged so as to be connected, that is, the shortest distance. The distance between the wiring 11 and each of the ground electrodes 12 and 13 disposed above and below is configured to be at least 30 μm or more. Reference numerals 14, 15, 16, 17, 18, and 19 schematically show electrode patterns of other circuit elements in the circuit configuration of the high-frequency switch module.
[0018]
As can be seen from FIG. 1, only the wiring 11 is provided in the region sandwiched between the ground electrodes 12 and 13, and the electrode patterns 14, 15, 16, 17, 18, 19 of other circuit elements, that is, a low-pass filter. Alternatively, electrode patterns of other circuit elements constituting the branching circuit are provided in a multilayer substrate other than the region sandwiched between the ground electrodes 12 and 13.
[0019]
【The invention's effect】
As described above, in the high-frequency switch module according to the present invention, the multilayer substrate, the external circuit connection terminal formed on the side surface or the back surface of the multilayer substrate, the GaAs switch element mounting pad formed on the surface of the multilayer substrate, A GaAs switch element mounted on the multilayer substrate via the GaAs switch element mounting pad, formed in the multilayer substrate, another circuit element other than the GaAs switch element, and formed in the multilayer substrate, A wiring for electrically connecting a pad for mounting a GaAs switch element and the external circuit connection terminal, and at least two ground electrodes formed in the multilayer substrate, and in a region sandwiched by at least two ground electrodes Since the wiring is arranged and another circuit element is arranged in the multilayer substrate other than the area sandwiched between the ground electrodes, Interference in the vertical direction between the wiring and another circuit element is avoided, and it becomes possible to electrically connect the GaAs switch element mounting pad and the external circuit connection terminal in the shortest distance, Transmission loss can be reduced.
[0020]
In addition, since the ground electrodes are arranged only above and below the wiring, that is, only the wiring is arranged in the area sandwiched between the ground electrodes, so another circuit pattern is arranged in the multilayer substrate other than the ground electrode. This makes it possible to reduce the size of the high-frequency switch module with less interference with other circuit elements.
[Brief description of the drawings]
FIG. 1 is a schematic longitudinal sectional view of a high-frequency switch module according to an embodiment of the present invention.
FIG. 2 is a schematic block diagram showing a circuit configuration of a high-frequency switch module according to the present invention.
3 is a schematic plan view showing a connection terminal configuration of a GaAs switch element used in the high-frequency switch module shown in FIG. 2;
FIG. 4 is a schematic top view illustrating the arrangement of wirings in the high-frequency switch module of the present invention.
FIG. 5 is a block diagram showing an example of a circuit configuration of a conventional high-frequency switch module.
FIG. 6 is a schematic plan view of a conventional high-frequency switch module.
[Explanation of symbols]
1, 2, 3, 4, 5, 6: Dielectric substrate 7: Multilayer substrate 8: GaAs switch element mounting pad 9: GaAs switch element 11: Electrical connection wiring 12, 13: Ground electrodes 14, 15, 16, 17, 18, 19: Other circuit patterns

Claims (4)

A multilayer substrate;
An external circuit connection terminal formed on the side surface or the back surface of the multilayer substrate;
A GaAs switch element mounting pad formed on the surface of the multilayer substrate;
A GaAs switch element mounted on the multilayer substrate via the GaAs switch element mounting pad;
Another circuit element other than the GaAs switch element formed in the multilayer substrate, and at least two ground electrodes formed in positions spaced apart from each other in the multilayer substrate;
Formed in a region of the multilayer substrate sandwiched between the ground electrodes that are spaced apart in the vertical direction in the multilayer substrate, wiring for electrically connecting the GaAs switch element mounting pad and the external circuit connection terminal;
Have
High-frequency switch module, wherein the sandwiched by the multilayer substrate other than the region by the ground electrodes were placed said other circuit elements.   2. The high frequency switch module according to claim 1, wherein the wiring for electrically connecting the GaAs switch element mounting pad and the external circuit connection terminal and the ground electrode are separated by at least 30 [mu] m or more.   The high frequency switch module according to claim 1, wherein the another circuit element is a low-pass filter through which a transmission signal passes.   The high frequency switch module according to claim 1 or 2, wherein the another circuit element is a branching circuit through which a reception signal or a transmission signal passes.

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