Murata Manufacturing Co., Ltd.

Shinya Watanabe

Koji Furutani

Takanori Uejima

Atsuyoshi Maeda

Naoki Nakayama

A high-frequency switch module includes a switch element, high-frequency circuits, and a GND circuit. The switch element includes an antenna port, switch ports, and an FET switch. The FET switch switches connection between the switch ports and the antenna port. The high-frequency circuits connect any of the switch ports to a signal processing circuit. In the GND circuit, the switch port, which is not connected to the high-frequency circuits, is directly connected to a GND electrode.

High-frequency switch module

A high-frequency module includes a GaAs switch defining an FET switch for selectively connecting one of four RF input-output terminals to an antenna input-output terminal to be connected to an antenna. A GSM transmission signal input terminal is connected to the RF input-output terminal of the GaAsSW through a low-pass filter, and a DCS/PCS transmission signal input terminal is connected to the RF input-output terminal through a low-pass filter. A GSM 850 reception signal output terminal and a PCS reception signal output terminal are connected to the RF input-output terminal through a diplexer, and a GSM 900 reception signal output terminal and a PCS reception signal output terminal are connected to the RF input-output terminal through a diplexer.

High-frequency module for transmitting and receiving transmission-reception signals of at least three communication systems using a single antenna

A FET switch enables an antenna input/output port connected to an antenna to connect to any of a port connected to a transmission signal input terminal and ports respectively connected to two reception signal output terminals by switching between the ports. After a transmission signal is input through the transmission signal input terminal and is then input from the port to the FET switch, harmonic distortion occurs and is output to the transmission signal input terminal side. A phase setting element connected to the port changes an impedance of the input side viewed from the port with respect to harmonics from an open state to a short-circuited state, so as to disperse the harmonics. Accordingly, harmonics returning to the port are greatly suppressed and minimized.

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, VC, and Vcthat are applied to the diode switch circuit and the GaAsIC switch.

High frequency module

A high-frequency switching module in which a high-frequency switch including a diode, which functions as a switching device, and a high-frequency filter including inductors and a capacitor are integrated with each other. The inductor defining a &#x3c0;-type high-frequency filter is connected directly and in series to the diode. By inserting the inductor, the cut-off frequency of a Chebyshev-type low-pass filter circuit produced when the diode is turned ON can be shifted to a lower frequency side, and also, the ripple can be suppressed to a small level.

High-frequency switching module and frequency-characteristic adjusting method for high-frequency circuit

A conductive paste which can form conductive films having superior stability due to prevention of change in viscosity with time, and having high reliability due to reduction of gas generation during a defatting is provided. The conductive paste is composed of a conductive powder having an average particle diameter of about 1.0 &mgr;m or less, an organic vehicle, an anionic macromolecular dispersing agent, and an amine having a boiling point of about 120&deg; C. or more, but about 220&deg; C. or less and constitutes about 0.1% to 5% by weight of 100% by weight of the conductive paste.

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Yasu, Japan

Shinya Watanabe