Patent Number: 6,294,952

Title: Quadrature demodulator quadrature demodulation method and recording medium

Abstract: A quadrature demodulator capable of calibrating an I (Q) signal conversion section without stopping the receiving operation performed by the quadrature demodulator. The quadrature demodulator comprises: an adder 32 for generating a pseudo noise superimposed signal obtained by adding a user signal IF and a pseudo noise PN; a signal conversion section 100 for generating a converted signal obtained by mixing the pseudo noise superimposed signal with a local frequency signal L1 of a predetermined local frequency; a first multiplier 72 for generating a correlated signal obtained by multiplying the converted signal with the pseudo noise, a first integrator 82 for integrating the correlated signal to provide an output; and a succeeding circuit 90 for processing the converted signal in a desired way. While performing calibration by causing the first multiplier 72 to extract the pseudo noise, the quadrature demodulator allows the succeeding circuit 90 to process the converted signal in a desired way. Therefore, the quadrature demodulator can calibrate the signal conversion section 100 without stopping its own receiving operation.

Inventors: Kato; Takashi (Tokyo, JP)

Assignee: Advantest Corporation

International Classification: H03D 3/00 (20060101); H03D 1/22 (20060101); H03D 1/00 (20060101); H04L 027/38 ()

Expiration Date: 09/25/2018