发明名称 |
Binary FM demodulator with self-adjusting resonant operating frequency according to demodulated binary output signal duty cycle |
摘要 |
A demodulator for demodulating a binary frequency-modulated signal includes a demodulator with a quadrature tank circuit and a duty cycle monitor circuit. The quadrature tank circuit has a voltage-controllable resonant frequency for compensating for shifts in the carrier frequency of the incoming signal and shifts in the tank circuit component values so as to allow the use of a high-Q tank circuit and thereby maximize use of the incoming signal energy. The quadrature tank circuit is a reactive circuit (with both inductive and capacitive elements) which includes a varactor diode having a voltage-controllable capacitance. The duty cycle monitor circuit measures the duty cycle of the demodulated binary output from the demodulator, and provides a control voltage to the quadrature tank circuit for adjusting its center frequency of operation.
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申请公布号 |
US5453714(A) |
申请公布日期 |
1995.09.26 |
申请号 |
US19950396441 |
申请日期 |
1995.02.28 |
申请人 |
NATIONAL SEMICONDUCTOR CORPORATION |
发明人 |
MADSEN, BENNY |
分类号 |
H03B1/00;H03B5/18;H03C3/09;H03L7/183;H04B1/40;H04L5/14;H04L27/12;H04L27/152;(IPC1-7):H03D3/02;H04L27/148 |
主分类号 |
H03B1/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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