JPH11313003A - High frequency switch module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a device in a dual band portable telephone, etc., by allowing 1st and 2nd switches provided in 1st and 2nd transmitting and receiving systems to have 1st-3rd voltage terminals and to share a voltage terminal that controls 1st and 2nd receiving systems with one terminal among them. SOLUTION: A 1st switch circuit switches transmission TX and receiving RX of a GSM system of a 1st transmitting and receiving system and connects a voltage terminal VC1 for diode control to a transmission line LG2. A 2nd switch circuit switches transmission TX and receiving RX of a DCS system of a 2nd transmitting and receiving system and connects a voltage terminal VC2 for diode control to a transmission line LP2. Also, a transmission line LG1 of the 1st switch circuit and a transmission line LP1 of the 2nd switch circuit are subjected to ground connection by a capacitor CGP and also are connected to a voltage terminal VC3 for diode control which is to be shared. When receiving of the GSM and DCS systems is valid, a prescribed voltage is applied to the terminal VC3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency composite component and, more particularly, to a high-frequency switch module which handles two transmission / reception systems.

[0002]

2. Description of the Related Art In a digital portable telephone or the like, a high-frequency switch is used to switch a connection between an antenna ANT and a transmission circuit TX and a connection between an antenna ANT and a reception circuit RX. As this high frequency switch,
There is one disclosed in JP-A-6-197040.

This conventional high-frequency switch includes a first diode having an anode connected to a transmitting circuit and a cathode connected to an antenna, a strip line connected between the antenna and the receiving circuit, and a strip line connected to the receiving circuit. The strip line includes a second diode connected to the anode and the cathode connected to the ground side, the strip line is built in the multilayer substrate, and the first diode and the second diode are mounted on the multilayer substrate.

[0004]

The spread of mobile phones in recent years has been remarkable, and the functions and services of mobile phones have been improved. As this new mobile phone,
Proposals for dual band mobile phones have been made. This dual-band mobile phone handles two transmission / reception systems while a normal mobile phone handles only one transmission / reception system. As a result, the user can select and use a convenient transmission / reception system.

[0005] In this dual-band mobile phone, if a dedicated circuit is configured for each transmission / reception system,
This leads to larger equipment and higher costs. It is advantageous to use a common part as much as possible for the common part to reduce the size and cost of the device.

The present invention provides a high-frequency switch module having a common antenna and switching between a transmission circuit and a reception circuit of a first transmission / reception system and a transmission circuit and a reception circuit of a second transmission / reception system. It is an object of the present invention to constitute a high-frequency switch module with one chip.

[0007]

The present invention is a high-frequency switch module for handling a first transmitting / receiving system (low-frequency side) and a second transmitting / receiving system (high-frequency side). A common terminal of two transmission / reception systems, a demultiplexing circuit connected to the common terminal for demultiplexing the two transmission / reception systems, and a first switch circuit provided in the demultiplexed first transmission / reception system. A first transmission system and a first reception system are separated, and a second switch circuit is provided in the split second transmission / reception system;
A high-frequency switch module for separating a second transmission system and a second reception system, wherein the first switch circuit and the second switch circuit use diodes, and apply a predetermined voltage to a voltage terminal that controls the diodes. A first voltage terminal for controlling the first transmission system, a second voltage terminal for controlling the second transmission system, and a first reception system. A high-frequency switch having a third voltage terminal for controlling the second reception system, wherein one terminal shares the voltage terminal for controlling the first reception system and the second reception system. Module.

The present invention is also a high-frequency switch module for connecting a common terminal of a first transmission / reception system and a second transmission / reception system of the branching circuit to an antenna.

Further, the present invention is a high-frequency switch module having a low-pass filter function from the branching circuit to the first transmission system and from the branching circuit to the second transmission system.

[0010] The present invention is also a high-frequency switch module which is composed of a laminate of dielectric green sheets on which an electrode pattern is formed, and a chip element arranged on the laminate, and which is made into one chip.

Further, the present invention is a high-frequency switch module in which the transmission line constituting the first switch circuit, the transmission line constituting the second switch circuit, and the branching circuit are constituted by an electrode pattern in a laminate. .

In the present invention, various configurations can be adopted as the branching circuit. In addition, the following is conceivable as a circuit configuration for giving each transmission system a low-pass filter function.

The demultiplexing circuit comprises a low-pass filter circuit for a first transmission / reception system, a notch filter circuit for a second transmission / reception system, and connects the low-pass filter circuit to the second transmission system. The low-pass filter circuit for the first transmission / reception system of the branching circuit has a low-pass filter function of the first transmission system.

The demultiplexing circuit comprises a low-pass filter circuit for the first transmission / reception system, a high-pass filter circuit for the second transmission / reception system, and connects the low-pass filter circuit to the second transmission system. The low-pass filter circuit for the first transmission / reception system of the branching circuit has a low-pass filter function of the first transmission system.

The demultiplexing circuit comprises a notch filter circuit for a first transmission / reception system and a band-pass filter circuit for a second transmission / reception system, and a low-pass filter circuit is connected to the first transmission system. The band-pass filter circuit for the second transmission / reception system of the branching circuit has a low-pass filter function of the second transmission system.

The demultiplexing circuit comprises a low-pass filter circuit for a first transmission / reception system and a band-pass filter circuit for a second transmission / reception system. The first transmission / reception system low-pass filter circuit of the demultiplexing circuit has a low-pass filter function of the first transmission system, and the second transmission / reception system band-pass filter circuit of the demultiplexer circuit is used for the second transmission system. It has a low-pass filter function.

The demultiplexing circuit comprises a notch filter circuit for a first transmission / reception system, a notch filter circuit for a second transmission / reception system, a low-pass filter circuit for a first transmission system, and a second transmission system. To the low pass filter circuit.

The demultiplexing circuit comprises a notch filter circuit for a first transmission / reception system, a high-pass filter circuit for a second transmission / reception system, a low-pass filter circuit for a first transmission system, and a second transmission system. To the low pass filter circuit.

The demultiplexing circuit comprises a band-pass filter circuit for a first transmission / reception system and a band-pass filter circuit for a second transmission / reception system. The first transmission / reception system band-pass filter circuit of the branching circuit has a low-pass filter function of the first transmission system, and the second transmission / reception system band-pass filter circuit of the branching circuit is connected to the second transmission system. Has a low-pass filter function.

The demultiplexing circuit comprises a band-pass filter circuit for a first transmission / reception system, a notch filter circuit for a second transmission / reception system, and connects a low-pass filter circuit to the second transmission system. The band-pass filter circuit for the first transmission / reception system of the branching circuit has a low-pass filter function of the first transmission system.

The demultiplexing circuit comprises a band-pass filter circuit for a first transmission / reception system, a high-pass filter circuit for a second transmission / reception system, and connects a low-pass filter circuit to the second transmission system. The band-pass filter circuit for the first transmission / reception system of the branching circuit has a low-pass filter function of the first transmission system.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, a first branching circuit is provided.
The common terminal of the transmission / reception system and the second transmission / reception system is connected to an antenna, and can be used as, for example, a high-frequency switch module for switching between an antenna of a dual-band mobile phone and transmission / reception circuits of the respective transmission / reception systems.

According to the present invention, the power supply circuit can be easily configured by sharing the voltage terminals for controlling the two switch circuits.

Further, the present invention comprises a laminated body obtained by appropriately laminating and integrally firing dielectric green sheets on which electrode patterns are formed, and chip elements such as diodes and chip capacitors disposed on the laminated body. One-chip integration can be achieved.

Further, according to the present invention, a transmission line constituting the first switch circuit, a transmission line constituting the second switch circuit, the demultiplexing circuit and / or the low-pass filter circuit are formed in a laminate by an electrode pattern. Can be configured. This electrode pattern can be formed on the dielectric green sheet by screen printing a conductive paste mainly composed of Ag. Of course, it is not limited only to Ag.

FIG. 1 is a circuit block diagram of a first embodiment according to the present invention. In the first embodiment, the branching circuit is constituted by two notch filters. In the first transmission / reception system, transmission TX and reception RX are switched by a switch circuit SW, and a low-pass filter circuit is provided in the transmission system. In the second transmission / reception system, the switch circuit SW
, The transmission TX and the reception RX are switched, and a low-pass filter circuit is provided in the transmission system.

The branching circuit of the present invention can be configured by combining a notch filter circuit, a low-pass filter circuit, a high-pass filter circuit, and a band-pass filter circuit. These circuits can be configured by a combination of an inductor component and a capacitor component. The same applies to a low-pass filter circuit that is appropriately added. These filter circuits are formed, for example, on a green sheet made of a ceramic dielectric material that can be fired at a low temperature.
The conductive paste containing g as a main component is printed to form a desired electrode pattern, which is appropriately laminated and fired integrally to form a laminated structure.

The switch circuit SW of the present invention is composed of a combination of a diode, a transmission line, a capacitor and the like.
Can be configured. This switch circuit SW also has a transmission line formed in a laminate, similarly to the above-described various filter circuits,
It is possible to mount and configure a diode on the laminate. Further, the capacitor can be configured in a laminate, or can be mounted on the laminate.

The high-frequency switch module according to the present invention comprises a laminated body obtained by appropriately laminating and integrally firing dielectric green sheets on which electrode patterns are formed, and chip elements such as diodes and chip capacitors disposed on the laminated body. And one chip can be achieved.
At this time, the transmission lines of the filter circuit and the switch circuit are formed in the laminate. By making this one chip, switch circuit, low-pass filter circuit,
In the case where each circuit element of the demultiplexing circuit is mounted on a substrate and connected, a matching circuit between the elements is not required, and the number of parts and the number of steps can be reduced.

FIG. 2 shows an example of an equivalent circuit diagram for constituting the first embodiment according to the present invention. The equivalent circuit diagram of this embodiment uses GSM as the first transmission / reception system and DCS as the second transmission / reception system. The antenna switch module connects the antenna with the two systems of GSM and DCS. The main part of the duplexer connected to the antenna ANT is two notch circuits. That is, the inductor LF1 and the capacitor C
F1 forms one notch circuit, and inductor LF2 and capacitor CF2 form another notch circuit. The capacitor CF3 connected to the ground is connected to one notch circuit. This capacitor CF3 is connected for the purpose of improving the low-pass filter characteristics of the demultiplexing characteristics. Further, another notch circuit has an inductor LF3 connected to the ground and a capacitor CF4 connected in series. This inductor LF
The capacitor 3 and the capacitor CF4 are connected for the purpose of improving the high-pass filter characteristic of the demultiplexing characteristic. This demultiplexing circuit can be configured with only two notch circuits.

Next, the first switch circuit will be described. The first switch circuit is a switch circuit on the upper side of FIG. 2 and switches between GSM transmission TX and reception RX. This switch circuit SW has two diodes D
G1 and DG2 and two transmission lines LG1 and LG2 are main components. The diode DG1 has an anode connected to the antenna ANT side, a cathode connected to the transmission TX side, and a transmission line LG1 connected to the ground at the cathode side. Is connected. A transmission line LG2 is connected between the antenna side and the reception RX, and a diode DG2 having a cathode connected to the reception side is connected to the diode DG2.
A capacitor CG6 is connected between the anode and the anode, and a series circuit of a resistor RG and an inductor LG is connected between the capacitor CG6 and the diode CG6, which serves as a diode control voltage terminal VC1.

The low-pass filter circuit inserted into the transmission system (transmission TX circuit side) includes an inductor LG3,
It is composed of capacitors CG3, CG4 and CG7, and is inserted between the diode DG1 of the switch circuit SW and the transmission line LG1.

Next, the second switch circuit will be described. The second switch circuit is a switch circuit on the lower side in FIG. 2 and switches between DCS transmission TX and reception RX. This switch circuit SW has two diodes D
P1 and DP2 and two transmission lines LP1 and LP2 are main components. The diode DP1 has an anode connected to the antenna ANT side, a cathode connected to the transmission TX side, and a transmission line LP1 connected to the ground at the cathode side. Is connected. A transmission line LP2 is connected between the antenna side and the reception RX, and a diode DP2 having a cathode connected to the reception side is connected to the diode DP2.
A capacitor CP6 is connected between the anode and the anode, and a series circuit of a resistor RP and an inductor LP is connected between the anode and the anode to serve as a diode control voltage terminal VC2.

The low-pass filter circuit inserted into the transmission system (transmission TX circuit side) includes an inductor LP3,
It is composed of capacitors CP3, CP4 and CP7 and is inserted between the diode DP1 of the switch circuit SW and the transmission line LP1.

The transmission line LG1 of the first switch circuit
And the transmission line LP1 of the second switch circuit are connected and grounded by a capacitor CGP, and are also connected to a diode control voltage terminal VC3.

The operation of this switch module is based on the GSM
To enable transmission of the system, a predetermined voltage is applied to the voltage terminal VC1. Similarly, when DCS transmission is enabled, a predetermined voltage is applied to the voltage terminal VC2. And G
When the reception of the SM system and the DCS system is enabled, the voltage terminal V
Apply a predetermined voltage to C3. Table 1 shows this relationship.

[0037]

[Table 1]

Next, FIG. 3 is a plan view of an embodiment for constructing the equivalent circuit diagram shown in FIG. 2, FIG. 4 is a perspective view of a laminate portion of the embodiment, and FIG. Shown in In this embodiment, the transmission lines of the demultiplexing circuit, the low-pass filter circuit, and the switch circuit are configured in a laminated body, and a diode and a chip capacitor are mounted on the laminated body to form a one-chip high-frequency switch module. Things.

The internal structure of the laminate will be described.
In this laminate, a green sheet made of a ceramic dielectric material that can be fired at a low temperature is prepared, and a conductive paste mainly composed of Ag is printed on the green sheet to form a desired electrode pattern. It is configured by laminating and integrally firing.

The internal structure will be described in the order of lamination.
First, the ground electrode 3 is placed on the lower green sheet 11.
1 is formed on almost the entire surface. Then, terminal electrodes 81, 83, 85, 87, 89, 91, 9 formed on the side surfaces
Connection portions for connection to the third and the third 95 are provided. The earth electrode 31 has a hole 9 formed therein.

Next, a dummy green sheet 12 on which no electrode pattern is printed is laminated. On the green sheet 13 thereon, three line electrodes 41, 42, 43
Are formed, and four line electrodes 44, 45, 46, 47 are formed on the green sheet 14 thereon.
A green sheet 15 on which two through-hole electrodes (the cross-marked circle is a through-hole electrode in the figure) is formed thereon, and a ground electrode 3 is formed thereon.
The green sheets 16 on which the sheets 2 are formed are stacked. The ground electrode 32 is shaped to avoid the through-hole electrode.

The line electrodes formed in the region sandwiched between the two ground electrodes 31 and 32 are appropriately connected to form a transmission line for the first and second switch circuits SW. The line electrodes 42 and 46 are connected by through-hole electrodes to form a transmission line LG1 of an equivalent circuit.
1 and 45 are connected by through-hole electrodes to form a transmission line LG2 of an equivalent circuit; line electrodes 43 and 47 are connected by through-hole electrodes to form a transmission line LP1 of an equivalent circuit; Of the transmission line LP2.

The green sheet 17 laminated on the green sheet 16 has electrodes 61 and 62 for capacitors,
63, 64, 65 and 66 are formed. The green sheet 18 laminated thereon also has the capacitor electrode 6
7, 68, 69 and 70 are formed. On the green sheet 19 laminated thereon, a capacitor electrode 71 is formed.

A green sheet 20 on which line electrodes 48 and 49 are formed is further laminated thereon.
Green sheets 21 on which line electrodes 50, 51, 52, 53, 54, 55 are formed are stacked. Further, a wiring pattern is formed on the green sheet 22 thereon, and a land for mounting element connection is formed on the uppermost green sheet 23.

The capacitor electrodes 61, 62, 63, 64, 65 of the green sheet 17 laminated on the green sheet 16 on which the upper earth electrode 32 is formed form a capacitance with the earth electrode 32. The capacitor electrode 61 is connected to the CG4 of the equivalent circuit by the capacitor electrode 62.
Is the equivalent circuit CG3, the capacitor electrode 63 is the equivalent circuit CP4, the capacitor electrode 64 is the equivalent circuit CP3, and the capacitor electrode 65 is the equivalent circuit CF3.
3.

The capacitor electrodes formed on the green sheets 17, 18, and 19 form a capacitance between each other, and constitute an equivalent circuit CF4 between the capacitor electrodes 66 and 70. 69, an equivalent circuit CP7 is formed, and between the capacitor electrodes 62 and 67,
The CG 7 of the equivalent circuit is formed, and the capacitor electrodes 70 and 71
, An equivalent circuit CF2 is formed, and the capacitor electrode 6
8 and 71 constitute an equivalent circuit CF1.

In the green sheets 20 and 21, the line electrodes 48 and 55 constitute the equivalent circuit LF1, the line electrodes 54 and 56 constitute the equivalent circuit LF2, and the line electrodes 49 and 53 constitute the equivalent circuit LF3. The line electrode 50 constitutes an equivalent circuit LG3, and the line electrode 52 constitutes an equivalent circuit LP3. The line electrode 51
Is a DC line.

These green sheets were pressed and fired integrally to obtain a laminate. A terminal electrode 8 is provided on the side surface of the laminate.
1, 82, 83, 84, 85, 86, 87, 88, 8
9, 90, 91, 92, 93, 94, 95, 96 were formed.

The diodes DG1, D
G2, DP1, DP2, chip capacitors CG1, CG
6, CP6 and CGP. The chip inductor LP4 and chip capacitor CP8 are mounted,
This LC series circuit need not be mounted. FIG. 3 is a plan view showing a state where the mounting element is mounted.
FIG. 2 also shows each terminal structure of the high-frequency switch module. A metal case is placed over the diode, chip capacitor, and chip inductor.

According to this embodiment, when the transmission lines of the first and second switch circuits are formed in the laminate, they are arranged in the region sandwiched between the ground electrodes. This prevents interference between the switch circuit, the demultiplexing circuit, and the low-pass filter circuit. The region sandwiched between the ground electrodes is arranged at the lower part of the laminate so that a ground potential can be easily obtained. Then, an electrode constituting a capacitor connected to the ground is formed so as to face the upper ground electrode.

Further, by arranging this transmission line portion below the laminate, the ground electrode can be arranged below the laminate, and the influence of the mounting substrate can be reduced. Furthermore, by disposing a capacitor electrode for forming a capacitor facing the ground electrode next thereto, and arranging the inductance components of the low-pass filter circuit and the branching circuit on the upper part, the inductance component can be separated from the ground electrode, and the short-circuit can be achieved. The required inductance value can be obtained by the transmission line length. Thus, the size of the high-frequency switch module can be reduced.

In the terminal electrodes formed on the side surfaces of the laminate of this embodiment, the GSM transmission TX terminal, the reception RX terminal, and the DCS , A transmission TX terminal and a reception RX terminal are formed. Since the high-frequency switch module is disposed between the antenna and the transmission / reception circuit, this terminal arrangement allows the antenna and the high-frequency switch module and the transmission / reception circuit and the high-frequency switch module to be connected with the shortest line, and an extra loss Can be prevented.

Further, on the opposite side, a GSM transmission TX terminal and a DCS transmission TX
A terminal is formed, and a GSM receiving R
An X terminal and a reception RX terminal of the DCS system are formed. 2
Since the two transmission circuits and the two reception circuits are arranged as a group, the transmission terminals and the reception terminals of the high-frequency switch module are arranged close to each other, making it possible to connect via the shortest path and prevent extra loss. it can.

In the laminated body of this embodiment, the antenna ANT terminal formed on the side surface, the GSM transmission TX terminal, the reception RX terminal, the DCS transmission TX terminal, and the reception RX
Each of the terminals and the voltage terminals VC1, VC2, and VC3 has a ground terminal formed between the terminals when viewed in the circumferential direction of the side surface, and each terminal is sandwiched between the ground terminals. Each input / output terminal (RF terminal) is arranged between the ground terminals. As a result, signal leakage between the terminals is blocked, interference is eliminated, and isolation between the signal terminals is ensured.

Further, there is a ground terminal on each side, so that the structure has a low loss.

The embodiment of the above-mentioned laminated structure corresponds to the circuit block diagram of the first embodiment shown in FIG. 1, but it is easy to configure another circuit within the scope of the present invention. be able to. For example, it is possible to change the electrode pattern of the inductor component and the capacitor component and change the connection method.

According to the embodiment of the present invention, for example, in a dual band mobile phone, it can be used for a portion connecting two systems and one antenna, and a plurality of circuit configurations can be configured on one chip. . For this reason,
Compared to a method of separately mounting and connecting a plurality of circuit elements, there are advantages such as a reduction in the number of components, a reduction in man-hours, and a reduction in size.

[0058]

According to the present invention, it is possible to provide a high-frequency switch module which is extremely useful in a dual-band portable telephone or the like. According to the present invention, the high-frequency switch module can be made compact and one-chip by using a laminated structure. As a result, in a dual-band mobile phone or the like, it is effective for downsizing the device.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a first embodiment according to the present invention.

FIG. 2 is an equivalent circuit diagram of an example of a circuit block diagram of the first embodiment according to the present invention.

FIG. 3 is a plan view of one embodiment for forming the equivalent circuit diagram shown in FIG. 2;

FIG. 4 is a perspective view of a laminate portion of one embodiment for forming the equivalent circuit diagram shown in FIG. 2;

FIG. 5 is an internal structural diagram of a laminated body according to one embodiment for forming the equivalent circuit diagram shown in FIG. 2;

[Explanation of symbols]

11, 12, 13, 14, 15, 1, 17, 18, 1,
9, 20, 21, 22, 23 Dielectric green sheet 31, 32 Earth electrode 41, 42, 43, 44, 45, 46, 47, 48, 4
9, 50, 51, 52, 53, 54, 55, 56 Line electrodes 61, 62, 63, 64, 65, 66, 67, 68, 6
9, 70, 71 Electrode for capacitor 81, 82, 83, 84, 85, 86, 87, 88, 8
9, 90, 91, 92, 93, 94, 95, 96 terminal electrodes

Continued on the front page (72) Inventor Toshihiko Tanaka 70-2, Minamisakaemachi, Tottori-shi, Tottori Hitachi Metals Co., Ltd. Inside the Tottori Plant (72) Inventor Takeshi Takeda 70-2, Minamisakaemachi, Tottori-shi, Tottori Hitachi Metals, Ltd. In company Tottori factory

Claims (5)

[Claims] An RF switch module for handling a first transmitting / receiving system (low frequency side) and a second transmitting / receiving system (high frequency side), wherein a common terminal of the first transmitting / receiving system and the second transmitting / receiving system is provided. And a demultiplexing circuit connected to the common terminal for demultiplexing the two transmission / reception systems. The first transmission / reception system that has been demultiplexed has a first switch circuit. A high-frequency switch module that divides a first reception system and has a second switch circuit in the second transmission / reception system that is split, and separates a second transmission system and a second reception system, 1
The switch circuit and the second switch circuit are switch circuits that use a diode, apply a predetermined voltage to a voltage terminal that controls the diode, and control the switch circuit, and that control the first transmission system. A first voltage terminal, a second voltage terminal for controlling the second transmission system, a third voltage terminal for controlling the first reception system and the second reception system, and A high-frequency switch module, wherein one terminal shares a voltage terminal for controlling the system and the second receiving system. 2. The high-frequency switch module according to claim 1, wherein a common terminal of the first transmission / reception system and the second transmission / reception system of the demultiplexing circuit is connected to an antenna. 3. A high-frequency switch module having a low-pass filter function from the branching circuit to a first transmission system and from the branching circuit to a second transmission system. 4. The high-frequency device according to claim 1, comprising a laminate of dielectric green sheets on which an electrode pattern is formed, and a chip element arranged on the laminate to form a single chip. Switch module. 5. The transmission line forming the first switch circuit, the transmission line forming the second switch circuit, and the branching circuit are formed by an electrode pattern in a laminate. The high-frequency switch module according to the above.