JP4247722B2 - High frequency switch module - Google Patents

Description

  The present invention relates to a high-frequency composite component, and relates to a high-frequency switch module that handles two transmission / reception systems.

  In a digital cellular phone or the like, a high frequency switch is used to switch the connection between the antenna ANT and the transmission circuit TX and the connection between the antenna ANT and the reception circuit RX. As this high-frequency switch, there is one disclosed in JP-A-6-197040.

  In this conventional high-frequency switch, a first diode whose anode is connected to the transmitting circuit side and whose cathode is connected to the antenna side, a strip line connected between the antenna and the receiving circuit, and an anode connected to the receiving circuit side A second diode having a 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.

  In recent years, the spread of mobile phones has been remarkable, and the functions and services of mobile phones have been improved. As this new mobile phone, a dual band mobile phone has been proposed. This dual-band mobile phone handles two transmission / reception systems, whereas an ordinary mobile phone handles only one transmission / reception system. Thereby, the user can select and use a convenient transmission / reception system.

  In this dual-band mobile phone, if a dedicated circuit is configured for each transmission / reception system, the size and cost of the device increase. Using common parts as much as possible for the common parts is advantageous in reducing the size and cost of the equipment.

  The present invention provides a high-frequency switch module having a common antenna and switching between a first transmission / reception system transmission circuit and reception circuit, and a second transmission / reception system transmission circuit and reception circuit, and the high-frequency switch module. The purpose of this is to make the device compact with one chip.

The present invention comprises a laminated body having an electrode pattern on the inner layer and the outer surface and an element mounted on the laminated body to constitute a switch circuit and a filter circuit, and a plurality of transmission / reception transmission circuits and reception circuits having different pass bands. A high-frequency switch module that switches between circuits, and includes a low-pass filter circuit in each of different paths between an antenna and a plurality of transmission circuits, and each low-pass filter circuit includes an inductor and a first that connects the inductor to ground. A capacitor and a second capacitor connected in parallel with the inductor, wherein a first capacitor electrode, a second capacitor electrode, an inductor line electrode, and a ground electrode are formed on an inner layer of the multilayer body; first electrode of the capacitor of the filter circuit is disposed opposite to one earth electrode, further, Lai for each inductor The electrodes are formed so as not to overlap each other on the layer above the layer on which the first capacitor electrode is formed, and connected to the element mounted on the laminate through the through-hole electrode, and the second capacitor Is formed in a layer between the layer on which the first capacitor electrode is formed and the layer on which the inductor line electrode is formed, and is opposed to the first capacitor electrode. A plurality of terminal electrodes formed on the outer surface of the laminate, a first transmission terminal to which a low-pass filter circuit disposed in a first path is connected, and a second transmission terminal; The high-frequency switch module is characterized in that an earth terminal connected to the earth electrode is formed between a second transmission terminal to which a low-pass filter circuit arranged in the path is connected.

Preferably, the switch circuit includes a transmission line, and a line electrode for the transmission line is formed in a layer below the layer on which the line electrode for the inductor is formed, and is connected to the element via a through-hole electrode. . The element is preferably a diode.

  According to the present invention, it is possible to provide a high-frequency switch module that is extremely useful in a dual-band mobile phone or the like. According to the present invention, this high-frequency switch module can be configured in a small size and in one chip by using a laminated structure.

  A circuit block diagram of the first embodiment according to the present invention is shown in FIG. In FIG. 1, the high frequency switch module of the present invention is a portion surrounded by a broken line. Further, this part is made into one chip. The high-frequency switch module of the present invention has, for example, a dual-band mobile phone antenna ANT, a GSM system, and a DCS as a configuration corresponding to two systems: a GSM system as a first transmission / reception system and a DCS1800 system as a second transmission / reception system. It can be used for distribution to each transmission / reception circuit of the system.

  In the first embodiment, the branching circuit is composed of a low-pass filter and a notch filter, and a low-pass filter is used for the first transmission / reception system and a notch filter is used for the second transmission / reception system. In the first transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW. In the second 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 order to make this first embodiment into a single chip, a laminated body in which a dielectric layer and an electrode layer are laminated, a transmission line for a switch circuit, an inductor component for a branching circuit, a capacitor component, In addition, an inductor component and a capacitor component for the low-pass filter circuit are configured, and an element such as a diode for the switch circuit is mounted on the laminated body, whereby a single chip can be obtained.

  A circuit block diagram of a second embodiment according to the present invention is shown in FIG. In the second embodiment, the branching circuit is composed of a low-pass filter and a high-pass filter, and a low-pass filter is used for the first transmission / reception system and a high-pass filter is used for the second transmission / reception system. In the first transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW. In the second 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.

  FIG. 3 shows a circuit block diagram of a first reference example that serves as a reference for the high-frequency switch module of the present invention. In the first reference example, the branching circuit is composed of a notch filter and a bandpass filter, and a notch filter is used for the first transmission / reception system and a bandpass filter is used for the second transmission / reception system. In the first transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW, and a low-pass filter circuit is provided in the transmission system. In the second transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW.

  FIG. 4 shows a circuit block diagram of a second reference example which serves as a reference for the high-frequency switch module of the present invention. In this second reference example, the branching circuit is composed of a low-pass filter and a band-pass filter, and a low-pass filter is used for the first transmission / reception system and a band-pass filter is used for the second transmission / reception system. In the first transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW. In the second transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW.

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

  A circuit block diagram of the fourth embodiment according to the present invention is shown in FIG. In the fourth embodiment, the branching circuit is composed of a notch filter and a high-pass filter, and a notch filter is used for the first transmission / reception system and a high-pass filter is used for the second transmission / reception system. In the first transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW, and a low-pass filter circuit is provided in the transmission system. In the second 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.

  FIG. 7 shows a circuit block diagram of a third reference example which serves as a reference for the high-frequency switch module of the present invention. In the third reference example, the branching circuit is composed of two band pass filters. In the first transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW. In the second transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW.

  FIG. 8 shows a circuit block diagram of an eighth embodiment according to the present invention as a fourth reference example which serves as a reference for the high-frequency switch module of the present invention. In the fourth reference example, the branching circuit is composed of a bandpass filter and a notch filter, and a bandpass filter is used for the first transmission / reception system and a notch filter is used for the second transmission / reception system. In the first transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW. In the second 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.

  FIG. 9 shows a circuit block diagram of a fifth reference example which serves as a reference for the high-frequency switch module of the present invention. In the fifth reference example, the branching circuit is composed of a bandpass filter and a highpass filter, and a bandpass filter is used for the first transmission / reception system and a highpass filter is used for the second transmission / reception system. In the first transmission / reception system, transmission TX and reception RX are switched by the switch circuit SW. In the second 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.

  The branching circuit of the present invention combines 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 added as appropriate. In these filter circuits, a conductive paste mainly composed of Ag, for example, is printed on a green sheet made of a ceramic dielectric material that can be fired at a low temperature to form a desired electrode pattern, which is appropriately laminated. It can be constituted by a laminated structure constituted by integrally firing.

  The switch circuit SW of the present invention can be configured by a combination of a diode, a transmission line, a capacitor, and the like. Similarly to the various filter circuits described above, the switch circuit SW can also be configured by configuring a transmission line in a laminated body and mounting a diode on the laminated body. In addition, the capacitor can be configured in the laminated body or can be mounted on the laminated body.

  The high-frequency switch module of the present invention includes a laminate obtained by appropriately laminating dielectric green sheets on which electrode patterns are formed and integrally firing, and chip elements such as diodes and chip capacitors disposed on the laminate. One chip can be achieved. At this time, the transmission lines of the filter circuit and the switch circuit are formed in the stacked body. This one-chip configuration eliminates the need for a matching circuit between elements when mounting and connecting each circuit element of the switch circuit, low-pass filter circuit, and branching circuit on the board, reducing the number of parts and man-hours. Reduction can be achieved.

  FIG. 10 shows an equivalent circuit diagram of an example for constituting the third 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 two GSM and DCS systems and the antenna. The duplexer portion connected to the antenna ANT has two notch circuits as main circuits. That is, the inductor LF1 and the capacitor CF1 constitute one notch circuit, and the inductor LF2 and the capacitor CF2 constitute another notch circuit. A capacitor CF3 connected to the ground is connected to one notch circuit. The capacitor CF3 is connected for the purpose of improving the low-pass filter characteristic of the demultiplexing characteristic. In addition, an inductor LF3 connected to the ground and a capacitor CF4 are connected in series to the other notch circuit. The inductor LF3 and the capacitor CF4 are connected for the purpose of improving the high-pass filter characteristic of the demultiplexing characteristic. This branching circuit may be 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. 10 and switches between GSM transmission TX and reception RX. This switch circuit SW includes two diodes DG1 and DG2 and two transmission lines LG1 and LG2. The diode DG1 has an anode connected to the antenna ANT side, a cathode connected to the transmission TX side, and a ground on the cathode side. Is connected to the transmission line LG1. A transmission line LG2 is connected between the antenna side and the reception RX, a diode DG2 having a cathode connected to the reception side is connected, and a capacitor CG6 is connected between the anode of the diode DG2 and the ground, In the meantime, a series circuit of a resistor RG and an inductor LG is connected and connected to the control circuit VC1.

  The low-pass filter circuit inserted on the transmission TX circuit side includes an inductor LG3 and 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 of FIG. 10, and switches between DCS transmission TX and reception RX. The switch circuit SW includes two diodes DP1 and DP2 and two transmission lines LP1 and LP2. The diode DP1 has an anode connected to the antenna ANT side, a cathode connected to the transmission TX side, and a ground connected to the cathode side. Is connected to the transmission line LP1. A transmission line LP2 is connected between the antenna side and the reception RX, a diode DP2 having a cathode connected to the reception side is connected, and a capacitor CP6 is connected between the anode of the diode DP2 and the ground, In the meantime, a series circuit of a resistor RP and an inductor LP is connected and connected to the control circuit VC2.

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

  Next, FIG. 11 is a plan view of an embodiment for constructing the equivalent circuit diagram shown in FIG. 10, FIG. 12 is a perspective view of the laminate portion of the embodiment, and FIG. 12 shows the internal structure of the laminate. It is shown in FIG. In this embodiment, a transmission line of a demultiplexing circuit, a low-pass filter circuit, and a switch circuit is configured in a multilayer body, and a diode and a chip capacitor are mounted on the multilayer body to configure a one-chip high frequency switch module. Is.

  The internal structure of this laminate will be described. For 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 constructed by laminating and firing together.

  This internal structure will be described according to the stacking order. First, the ground electrode 31 is formed on almost the entire surface of the lower green sheet 11. And the connection part for connecting with the terminal electrodes 81, 83, 85, 87, 89, 91, 93, 94, 95 formed in a side surface is provided.

  Next, a dummy green sheet 12 on which no electrode pattern is printed is laminated. Three line electrodes 41, 42, 43 are formed on the green sheet 13 thereon, and four line electrodes 44, 45, 46, 47 are formed on the green sheet 14 thereon. On top of that, a green sheet 15 on which two through-hole electrodes (the one with a cross mark in the circle in the figure is a through-hole electrode) is laminated, and a green electrode on which a ground electrode 32 is formed is laminated thereon. Sheets 16 are laminated.

  Line electrodes formed in a 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 constitute an equivalent circuit transmission line LG1, and the line electrodes 41 and 45 are connected by through-hole electrodes to constitute an equivalent circuit transmission line LG2, Reference numeral 47 is connected by a through-hole electrode, and constitutes an equivalent circuit transmission line LP1, and the line electrode 44 constitutes an equivalent circuit transmission line LP2.

  Capacitor electrodes 61, 62, 63, 64, 65, 66 are formed on the green sheet 17 laminated on the green sheet 16. Capacitor electrodes 67, 68, 69 and 70 are also formed on the green sheet 18 laminated thereon. Capacitor electrodes 71 are formed on the green sheet 19 laminated thereon.

  Furthermore, the green sheet 20 on which the line electrodes 48 and 49 are formed is laminated thereon, and the green sheet 21 on which the line electrodes 50, 51, 52, 53, 54, and 55 are formed is laminated thereon. . On the uppermost green sheet 22, lands 23, 24, 25, 26, 27, 28, 29, 33, 34, 35, 36, and 37 for connecting mounted elements are formed.

  Capacitor electrodes 61, 62, 63, 64, and 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, and the capacitor The electrode 61 is an equivalent circuit CG4, the capacitor electrode 62 is an equivalent circuit CG3, the capacitor electrode 63 is an equivalent circuit CP4, the capacitor electrode 64 is an equivalent circuit CP3, and the capacitor electrode 65 constitutes CF3 of an equivalent circuit.

  The capacitor electrodes formed on the green sheets 17, 18, 19 form a capacitance between them, and an equivalent circuit CF 4 is formed between the capacitor electrodes 66 and 70, and similarly between the capacitor electrodes 64 and 69. The equivalent circuit CP7 is formed, the equivalent circuit CG7 is formed between the capacitor electrodes 62 and 67, the equivalent circuit CF2 is formed between the capacitor electrodes 70 and 71, and the capacitor electrodes 68 and 71 are connected. Between them, an equivalent circuit CF1 is formed.

  In the green sheets 20 and 21, the line electrodes 48 and 55 constitute an equivalent circuit LF1, the line electrodes 54 and 56 constitute an equivalent circuit LF2, and the line electrodes 49 and 53 constitute an 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 pressure-bonded and integrally fired to obtain a laminate. Terminal electrodes 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96 were formed on the side surface of this laminate. This external view is shown in FIG.

  On this laminate, diodes DG1, DG2, DP1, DP2, and chip capacitors CG1, CG6, CP1, CP6 were mounted. Further, the chip inductor LP4 and the chip capacitor CP8 are mounted, but this LC series circuit may not be mounted. FIG. 11 is a plan view showing a state in which this mounting element is mounted. FIG. 11 also shows the mounting configuration of the high-frequency switch module.

  According to this embodiment, when the transmission lines of the first and second switch circuits are formed in the laminated body, they are arranged in a region sandwiched between the ground electrodes. As a result, interference between the switch circuit, the branching circuit, and the low-pass filter circuit is prevented. And the area | region pinched | interposed by this earth electrode is arrange | positioned in the lower part of a laminated body, and it is easy to take an earth potential. And the electrode which comprises the capacitor | condenser connected between earth | grounds is formed facing the upper earth electrode.

  Further, by configuring this transmission line portion on the lower side of the laminated body, the ground electrode can be arranged on the lower side of the laminated body, and the influence of the mounting substrate can be reduced. Furthermore, the capacitor electrode for forming the capacitor facing the ground electrode is disposed next, and the inductance component of the low-pass filter circuit and the branching circuit is disposed on the upper part, so that the inductance component can be separated from the ground electrode, and is short. The required inductance value can be obtained with the transmission line length. Thereby, size reduction of a high frequency switch module can be achieved.

  Further, in the terminal electrode formed on the side surface of the laminated body of this embodiment, the GSM transmission TX terminal, the reception RX terminal, and the DCS transmission TX are arranged on the opposite side of the antenna ANT terminal which is divided into two. A terminal and a reception RX terminal are formed. Since this high-frequency switch module is arranged 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, resulting in an extra loss. Can be prevented.

  Further, on the opposite side, a GSM transmission TX terminal and a DCS transmission TX terminal are formed on one side of the half, and a GSM reception RX terminal and a DCS reception RX terminal are formed on the other side. Is formed. Since the two transmitter circuits and the two receiver circuits are arranged together, the transmitter terminals and receiver terminals of the high-frequency switch module are arranged close to each other, making it possible to connect in the shortest path, thereby reducing extra losses. Can be prevented.

  In the laminated body of this embodiment, the antenna ANT terminal, the GSM transmission TX terminal, the reception RX terminal, the DCS transmission TX terminal, and the reception RX terminal formed on the side surface are all viewed in the circumferential direction of the side surface. In this case, a ground terminal is formed between the terminals, and each terminal is sandwiched between the ground terminals. Each input / output terminal is disposed between ground terminals. As a result, signal leakage between the terminals is blocked, interference is eliminated, and isolation between the signal terminals is ensured.

  In the equivalent circuit of the above embodiment, the control power supply terminals of the switches are provided separately for each switch, but two switches may be controlled as one control power supply terminal.

  The embodiment of the above laminated structure corresponds to the circuit block diagram of the fifth embodiment shown in FIG. 5. However, the embodiment shown in the other circuit block diagram is configured by the laminated structure. It can be easily configured as a modified example. For example, it is possible to change the connection method by changing the electrode pattern of the inductor component and the capacitor component.

  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 a single chip. For this reason, compared with the method of mounting and connecting a plurality of circuit elements separately, there are advantages such as reduction in the number of parts, reduction in man-hours, and miniaturization.

  Since the high-frequency switch module can be configured in a small size and a single chip by using a laminated structure, it is effective for miniaturization of equipment in a dual-band mobile phone or the like.

1 is a circuit block diagram of a first embodiment of a high-frequency switch module according to the present invention. It is a circuit block diagram of 2nd Example of the high frequency switch module which concerns on this invention. It is a circuit block diagram of the 1st reference example of the high frequency switch module concerning the present invention. It is a circuit block diagram of the 2nd reference example of the high frequency switch module concerning the present invention. It is a circuit block diagram of 3rd Example of the high frequency switch module which concerns on this invention. It is a circuit block diagram of the 4th example of the high frequency switch module concerning the present invention. It is a circuit block diagram of the 3rd reference example of the high frequency switch module concerning the present invention. It is a circuit block diagram of the 4th reference example of the high frequency switch module concerning the present invention. It is a circuit block diagram of the 5th reference example of the high frequency switch module concerning the present invention. It is an equivalent circuit diagram of an example of the circuit block diagram of 5th Example which concerns on this invention. It is a top view of one Example for comprising the equivalent circuit schematic shown in FIG. It is a perspective view of the laminated body part of one Example for comprising the equivalent circuit schematic shown in FIG. It is an internal structure figure of the laminated body of one Example for comprising the equivalent circuit schematic shown in FIG.

Explanation of symbols

11, 12, 13, 14, 15, 1, 17, 18, 19, 20, 21, 22 Dielectric green sheets 31, 32 Ground electrodes 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56 Line electrodes 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71 Capacitor electrodes 81, 82, 83, 84, 85, 86 , 87, 88, 89, 90, 91, 92, 93, 94, 95, 96 Terminal electrodes

Claims (3)

A laminate having an electrode pattern on the inner layer and the outer surface, and elements mounted on the laminate constitute a switch circuit and a filter circuit, and switch between a plurality of transmission / reception transmission circuits and reception circuits having different pass bands. A high frequency switch module,
Each of the different paths between the antenna and the plurality of transmission circuits has a low pass filter circuit, each low pass filter circuit having an inductor, a first capacitor connecting the inductor to ground, and a first capacitor connected in parallel with the inductor. 2 capacitors, and an electrode for the first capacitor, an electrode for the second capacitor , a line electrode for the inductor, and a ground electrode are formed on the inner layer of the laminate, and one electrode for the first capacitor of each low-pass filter circuit is provided. Placed opposite to the ground electrode,
Furthermore, the line electrodes for each inductor are formed so as not to overlap each other on the layer above the layer on which the first capacitor electrode is formed, and are connected to the elements mounted on the multilayer body through the through-hole electrodes. The electrode for the second capacitor is formed in a layer between the layer in which the electrode for the first capacitor is formed and the layer in which the line electrode for the inductor is formed, and the first capacitor Arranged opposite to the electrode for
A plurality of terminal electrodes are formed on the outer surface of the laminate, and a first transmission terminal to which a low-pass filter circuit disposed in the first path is connected and a second path are disposed in the terminal electrodes. A high-frequency switch module, wherein a ground terminal connected to the ground electrode is formed between the second transmission terminal to which the low-pass filter circuit is connected. The switch circuit includes a transmission line, and a line electrode for the transmission line is formed in a layer below the layer in which the line electrode for the inductor is formed, and is connected to the element through a through-hole electrode. The high frequency switch module according to claim 1. The high frequency switch module according to claim 1 , wherein the element is a diode .

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