90° PHASE SHIFTER

摘要

PROBLEM TO BE SOLVED: To provide a 90 deg. phase shifter, which operates at high speed in simple configuration, capable of extracting a 90 deg. phase difference signal having the duty ratio of 50% from a signal of a frequency divided into the stages of an odd number. SOLUTION: This device is provided with a second frequency divider for dividing the frequency of a signal outputted from a first local oscillator into N stages (N is an odd number), a third phase shifter for distributing a signal outputted from the second frequency divider to two orthogonal signals and outputting them, a fourth mixer circuit for converting a signal outputted from the third phase shifter to a double frequency and outputting it, and a fifth filter circuit for extracting only the 2/N-fold frequency component of a local oscillation frequency from a signal outputted from the fourth mixer circuit. Then, by inputting a signal outputted from the fifth filter circuit to a sixth 1/2 frequency divider circuit for dividing a frequency to two stages, the signal of a frequency divided into N stages of the local oscillation frequency having a 90 deg. phase difference can be extracted from the sixth 1/2 frequency divider circuit.