High frequency module

• US 7,711,389 B2
• Filed: 10/21/2004
• Issued: 05/04/2010
• Est. Priority Date: 11/11/2003
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Watanabe, Shinya, Furutani, Koji
• Primary Examiner(s): Milord; Marceau
• Application Number:
  US10/595,782
• Publication Number:
  US 20090075604A1
• Time in Patent Office: 2,021 Days
• Field of Search: 455/552.1, 455/83, 455/78, 455/80, 455/275, 455/273, 455/553.1, 455/550.1
• US Class Current: 455/552.1
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence

Abstract

A high frequency module for transmitting and receiving, for example, communication signals of GSM/DCS/PCS/WCDMA systems through a single antenna, is provided at a relatively small size and low cost. The high frequency module includes a diplexer arranged to separate communication signals from the antenna into GSM communication signals in lower frequency bands and POS/DOS/WODMA communication signals in higher frequency bands, a diode switch circuit that is connected to a input and output terminal of the GSM communication signal of the diplexer and is arranged to switch transmission and reception of the GSM communication signal, and a multipoint GaAsIC switch that is connected to the GSM/DCS/PCS/WCDMA communication signals of the diplexer and is arranged to switch transmission and reception of these signals. The high frequency module switches the four types of communication signals by changing the patterns of controls signals VcG, VC1, and Vc2 that are applied to the diode switch circuit and the GaAsIC switch.

Claims

1. A high frequency module comprising:

a diplexer arranged to separate signals of a plurality of communication systems transmitted and received via an antenna, the communication systems having transmission and reception bands of different frequency bands, the signals of a plurality of communication systems being separated into a signal of a first communication system having a transmission and reception band in an area higher than a predetermined frequency and a signal of a second communication system having a transmission and reception band in an area lower than a predetermined frequency;

a first switch circuit arranged to switch transmission and reception of the signal of the second communication system having a transmission and reception band in a lower area; and

a second switch circuit arranged to switch transmission and reception of the signal of the first communication system having a transmission and reception band in a higher area;

wherein

the diplexer, the first switch circuit, and the second switch circuit include electrodes provided on a laminated body constructed by stacking a plurality of dielectric layers and components mounted on the laminated body;

the diplexer includes a low pass filter arranged to allow the signal of the second communication system having a transmission and reception band in an area lower than a predetermined frequency to pass through and a high pass filter arranged to allow the signal of the first communication system having a transmission and reception band in an area higher than a predetermined frequency to pass through;

the first switch circuit includes a first transmission and reception signal input and output unit connected to the low pass filter of the diplexer and configured to output a predetermined transmission signal of the second communication system having a transmission and reception band in a lower area and to input a predetermined reception signal, a first transmission signal input unit arranged to input the transmission signal, a first reception signal output unit for outputting the reception signal, and a diode arranged to switch the connection between the first transmission and reception signal input and output unit and one of the first transmission signal input unit and the first reception signal output unit in accordance with a control signal;

the second switch circuit includes a second transmission and reception signal input and output unit connected to the high pass filter of the diplexer and configured to output a predetermined transmission signal of the first communication system having a transmission and reception band in a higher area and to input a predetermined reception signal, a second transmission signal input unit arranged to input the transmission signal, a second reception signal output unit arranged to output the reception signal, and a FET switch element arranged to switch the connection between the second transmission and reception signal input and output unit and one of the second transmission signal input unit and the second reception signal output unit in accordance with a control signal,

the high pass filter includes a first capacitive element connected between the antenna and the second switch circuit and a series circuit having a dielectric element and a second capacitive element, the series circuit being connected between the second switch side of the first capacitive element and the ground; and

the second capacitive element includes a ground electrode provided on a dielectric layer close to the bottom surface of the laminated body and an electrode opposing the ground electrode.

2. The high frequency module according to claim 1, wherein the diplexer is arranged to separate signals of at least four communication systems into a signal of a first communication system having a transmission and reception band in an area higher than a predetermined frequency and a signal of a second communication system having a transmission and reception band in an area lower than a predetermined frequency.

3. The high frequency module according to claim 1, wherein the FET switch element is a GaAs switch.

4. The high frequency module according to claim 1, wherein a low pass filter includes a third capacitive element and a second dielectric element, the low pass filter being provided between the diplexer and the second switch circuit.

5. The high frequency module according to claim 1, wherein a low pass filter includes a fourth capacitive element and a third dielectric element, the low pass filter being provided on the transmission signal input unit side of the second switch circuit.

6. The high frequency module according to claim 5, wherein the second dielectric element and the third dielectric element are provided in different areas when viewed from the top.