Patent ID: 6057723
Filing Date: 2000-05-02
Classification: H03H

Abstract:
A phase shifter for switching phase of an output signal, comprising:a first all pass filter which is composed of a plurality of first elements formed on an IC chip and outputs a first output signal by shifting a phase of said input signal;a second all pass filter which is composed of a plurality of second elements which is simultaneously formed with said plurality of first elements on said IC chip, has the same circuit structure as said first all pass filter and outputs a second output signal having a different phase from the first output signal by shifting a phase of said input signal; anda signal selecting means for outputting one output signal selected from said first output signal outputted from said first all pass filter and said second output signal outputted from said second all pass filter;wherein said first all pass filter and said second all pass filter each comprising:a bridge circuit composing a plurality of resistors and a plurality of capacitors; andan output buffer amplifier connected to a back stage of said bridge circuit.