Demodulators – Amplitude modulation demodulator – Having specific distortion – noise or other interference...
Patent
1985-04-26
1986-12-30
LaRoche, Eugene R.
Demodulators
Amplitude modulation demodulator
Having specific distortion, noise or other interference...
329124, 358 25, 455337, H03D 306
Patent
active
046331875
ABSTRACT:
A demodulating circuit for an amplitude-modulated signal comprises an input terminal to be supplied with an input signal comprising at least a modulated carrier signal amplitude-modulated by an information signal, the modulated carrier signal having a predetermined phase; an oscillator for generating a first demodulating carrier the phase of which is displaced from that of the modulated carrier signal by 90.degree., and a second demodulating carrier which has the same phase as that of the modulated carrier signal; a first synchronous demodulator for demodulating the input signal with the first demodulating carrier; a second synchronous demodulator for demodulating the input signal with the second demodulating carrier; a level detector for detecting the level of a predetermined portion of the demodulated output of the first synchronous detector; a control circuit supplied with the output of the level detector for controlling the oscillator so that the phase of the second demodulating carrier is synchronous with that of the modulated carrier signal; and an output terminal connected to the second synchronous detector for receiving the demodulated information signal from the second synchronous detector. The demodulator circuitry according to the invention performs stable demodulation without using a limiter, and with the phase of the carrier signal for demodulation under its control, thus being free from dependence of the phase of carrier signals for demodulation on the level of input signals.
REFERENCES:
patent: 4100499 (1978-07-01), Monrolin
Asakura Hisao
Nishimura Yoshikazu
Yasukouchi Yoshimi
Eslinger Lewis H.
LaRoche Eugene R.
Lee James C.
Sinderbrand Alvin
Sony Corporation
LandOfFree
AM synchronous detecting circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with AM synchronous detecting circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and AM synchronous detecting circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1550038