| 摘要 |
PROBLEM TO BE SOLVED: To obtain a phase detecting circuit capable of outputting phase data without using a quadrature mixer nor a local oscillator. SOLUTION: This phase detecting circuit provided with a known delta-sigma phase detector 50 for detecting a phase of a received signal from a baseband signal is provided with a sampling part 20 for sampling an intermediate frequency signal, a frequency converting part 30 for multiplying the sampled signal by a prescribed coefficient to thereby convert the signal into baseband signals for an in-phase channel and a quadrature channel, and low pass filter parts (40 and 41) for the in-phase channel and the quadrature channel for respectively eliminating double components of intermediate frequencies from the baseband signal of the in-phase channel and the baseband signal of the quadrature channel, and inputs an output of each of the low pass filter parts to the delta-sigma phase detector 50. COPYRIGHT: (C)2005,JPO&NCIPI
|
