Abstract: A switch circuit for selectively switching connection of an antenna side circuit with a reception circuit and a transmission circuit of two communication systems one of which has a reception frequency band partially overlapped with a transmission frequency of the other. The switch circuit includes (a) a first switch unit for switching connection to the antenna side circuit with the transmission circuit side of the first and the second communication systems and the reception circuit side of the first and the second communication system and (b) a second switch unit connected between the first switch unit and the reception circuit of the first end and the second communication system for switching connection of the antenna side circuit with the reception circuit of the first and the second communication system. (c) The transmission circuit side of the first and the second communication system of the first switch unit is connected to a transmission circuit shared by the first and the second communication system.

Abstract: A multi-band high-frequency circuit for performing wireless communications among pluralities of communication systems having different communication frequencies, comprising a high-frequency switch circuit comprising switching elements for switching the connection of pluralities of multi-band antennas to transmitting circuits and receiving circuits; a first diplexer circuit disposed between the high-frequency switch circuit and transmitting circuits for branching a high-frequency signal into frequency bands of the communication systems; a second diplexer circuit disposed between the high-frequency switch circuit and receiving circuits for branching a high-frequency signal into frequency bands of the communication systems; the first and second diplexer circuits each comprising a lower-frequency filter circuit and a higher-frequency filter circuit, a bandpass filter circuit being used as the lower-frequency filter circuit in the second diplexer circuit, or disposed between the lower-frequency filter circuit in t

Abstract: A switch circuit for selectively switching connection of an antenna side circuit with a reception circuit and a transmission circuit of two communication systems one of which has a reception frequency band partially overlapped with a transmission frequency of the other. The switch circuit includes (a) a first switch unit for switching connection of the antenna side circuit with the transmission circuit side of the first and tie second communication systems and the reception circuit side of the first and the second communication system and (b) a second switch unit connected between the first switch unit and the reception circuit of the first and the second communication system for switching connection of the antenna side circuit with the reception circuit of the first and the second communication system. (c) The transmission circuit side of the first and the second communication system of the first switch unit is connected to a transmission circuit shared by the first and the second communication system.

Abstract: A high-frequency circuit for use in a dual-band wireless communications apparatus selectively using first and second frequency bands, comprising a diplexer connected to the output of a power amplifier for sending either one of transmission signals in the first and second frequency bands to an antenna, a coupler having a primary line connected to a common end of the diplexer and a secondary line, a detector comprising a detection diode for detecting a transmission power of a high-frequency signal sent from the secondary line of the coupler, and a harmonics-suppressing circuit disposed between the secondary line of the coupler and the detection diode.

Abstract: A multi-band antenna switch circuit including a diplexer connected to an antenna terminal for demultiplexing signals of different passing bands, a first and a second switch circuit for switching a high frequency signal and a low frequency signal demultiplexed by the diplexer to a plurality of transmission/reception terminals, a first and a second low pass filter connected to a transmission path between the diplexer and the transmission terminal or between the first and the second switch circuit and the transmission terminal, and a notch filter provided between the diplexer and the first switch circuit or between the diplexer and the second switch circuit.

Abstract: An unbalanced-balanced multiband filter module comprising three high-frequency switches each comprising a switching element, and two unbalanced-balanced bandpass filters having different transmitting frequency bands, a first high-frequency switch being connected to an unbalanced port of the module, an unbalanced port of the first unbalanced-balanced bandpass filter, and an unbalanced port of the second unbalanced-balanced bandpass filter; a second high-frequency switch being connected to a first balanced port of the module, a first balanced port of the first unbalanced-balanced bandpass filter, and a first balanced port of the second unbalanced-balanced bandpass filter; a third high-frequency switch being connected to a second balanced port of the module, a second balanced port of the first unbalanced-balanced bandpass filter, and a second balanced port of the second unbalanced-balanced bandpass filter; and the first to third high-frequency switches being switched depending on a passing high-frequency signal,

Abstract: A switch circuit for selectively switching connection of an antenna side circuit with a reception circuit and a transmission circuit of two communication systems one of which has a reception frequency band partially overlapped with a transmission frequency of the other. The switch circuit includes (a) a first switch unit for switching connection of the antenna side circuit with the transmission circuit side of the first and tie second communication systems and the reception circuit side of the first and the second communication system and (b) a second switch unit connected between the first switch unit and the reception circuit of the first and the second communication system for switching connection of the antenna side circuit with the reception circuit of the first and the second communication system. (c) The transmission circuit side of the first and the second communication system of the first switch unit is connected to a transmission circuit shared by the first and the second communication system.

Abstract: A multi-band transceiver has a function of sharing transmitted and received signals of multiple frequency bands by the same antenna. The multi-band transceiver mounts multiple filters that correspond to the multiple frequency bands and multiple amplifiers for amplifying the transmitted signals on the same substrate, and arranges the multiple filters in close vicinity to the amplifier in the order where the multiple filters are excellent in their temperature characteristic.

Abstract: A multi-band antenna switch circuit including a diplexer connected to an antenna terminal for demultiplexing signals of different passing bands, a first and a second switch circuit for switching a high frequency signal and a low frequency signal demultiplexed by the diplexer to a plurality of transmission/reception terminals, a first and a second low pass filter connected to a transmission path between the diplexer and the transmission terminal or between the first and the second switch circuit and the transmission terminal, and a notch filter provided between the diplexer and the first switch circuit or between the diplexer and the second switch circuit.

Abstract: An antenna switch module connected to a common antenna for switching the connection of the antenna to a transmission circuit or a receiving circuit in plural transmitting/receiving systems having different passbands, comprising a diplexer circuit comprising a low-pass filter and a high-pass filter; a first switch circuit connected to the low-pass filter and for switching a transmitting line and a receiving line, a second switch circuit connected to the high-pass filter for switching a transmitting line and a receiving line; a third switch circuit connected to the first switch circuit for switching the receiving line from the first switch circuit; and a fourth switch circuit connected to the second switch circuit for switching the receiving line from the second switch circuit; at least part of transmission lines constituting LC circuits in the diplexer circuit and the first and second switch circuits being electrode patterns formed in a multilayer substrate constituted by plural dielectric layers; and chip ele

Abstract: A high-frequency switch module which comprises a high-frequency switch circuit connected among an antenna, a transmission circuit, and a reception circuit and comprising switching elements and a surface acoustic wave filter connected between the high-frequency switch circuit and the reception circuit, uses a laminate constituted of dielectric layers having electrode patterns as the multilayered board, and has a phase correction circuit disposed between the switch circuit and the surface acoustic wave filter, wherein the high-frequency switch circuit comprises a switching element, a transmission line, and a capacitor as main elements, with at least a part of the transmission line and the capacitor constituted of an electrode pattern in the laminate, and with the surface acoustic wave filter mounted on the laminate.