Patent ID: 7003312
Filing Date: 2006-02-21
Classification: H01P,H04B

Abstract:
1. A high-frequency switch circuit common to high-frequency signals of a plurality of frequency bands comprising: a first high-frequency switch connected to a first terminal for inputting and outputting high-frequency signals for passing a transmitting signal of a first frequency band or a transmitting signal of a second frequency band while blocking a received signal of said first frequency band and a received signal of said second frequency band; and a branching circuit comprising a first high-frequency circuit comprising a first phase shifter connected to said first terminal and a first bandpass filter disposed downstream thereof, and a second high-frequency circuit comprising a second phase shifter connected to said first terminal and a second bandpass filter disposed downstream thereof, a transmission line for constituting said first phase shifter having such a line length that the impedance of said first high-frequency circuit viewed from the input side is substantially open at a passband frequency of said second bandpass filter, a transmission line for constituting said second phase shifter having such a line length that the impedance of said second high-frequency circuit viewed from the input side is substantially open at a passband frequency of said first bandpass filter, whereby one received signal in said first and second frequency bands is permitted to pass while the other received signal is shut off.