Pioneer Electronic Corporation

Kiyoshi Ohtaki

Kohji Ishida

A low-pass filter circuit for suppressing a subcarrier contained in an FM stereo demodulation signal in which the output signal of the circuit is unaffected by magnetic distortion. The FM stereo demodulation signal is applied through a low-pass filter to n sample-and-hold circuits connected in parallel with one another. The outputs of the sample-and-hold circuits are summed to form an output signal in which the subcarrier signal has been suppressed. The n sample-and-hold circuits are driven with a corresponding number of sampling pulse signals of different phases.

Low-pass filter circuit

A multipath distortion reducing circuit particularly adapted for use with stereophonic receiving circuits in which the amount of mixing between right and left channels is reduced. In accordance with the invention, the envelope of the received FM signal is AM detected, and the envelope detected circuit is multiplied by the FM detected signal differentiated to provide a distortion cancelling signal. The distortion cancelling signal is summed with the detected FM signal to provide an output having a reduced multipath distortion component.

Growing community of inventors

Tokyo, Japan

Kiyoshi Ohtaki