Patent ID: 6903603

Claim:
A phase detecting circuit comprising: a first quantizing unit that quantizes a phase of a received baseband signal; a converting and selecting unit that linearly converts the received signal based on a predetermined rule, and selectively outputs the signal after the linear conversion; an integrating unit that integrates the output from the converting and selecting unit; a second quantizing unit that quantizes the integration result by deciding the sign of the integration result; a delay unit that delays the output from the second quantizing unit by a predetermined first time, and outputs the delayed signal to the converting and selecting unit; an adding unit that adds the output from the first quantizing unit and the output from the second quantizing unit modulo the quantized value of the phase 2π; and a low-pass filter unit that sequentially latches phase values after the addition with internal shift registers, converts the whole data within the shift registers based on a predetermined rule when the phase values that cross over the quantized value of the phase 2π it exist in the whole data, does not carry out the conversion when the phase values that cross over the quantized value of the phase 2π do not exist, averages the phase values in this state, and outputs the phase value after smoothing quantization noise.