发明名称 |
Quadrature demodulator operable over different IF frequencies |
摘要 |
A demodulation circuit (10) performs quadrature demodulation on an IF input signal. The IF input signal processes through a preamplifier (12) to one input of a mixer (14). The mixer output goes to first and second multipliers (20, 22). A VCO (24) generates an oscillator signal that processes through a first multiplier (26) and first and second dividers (28, 30) to generate in-phase and quadrature recovered carrier signals that are applied to second inputs of the first and second multipliers which in turn produce the in-phase and quadrature demodulated baseband signals. A switching arrangement (32, 38, 40) for the multiplier and dividers provides the proper frequency signal to a second input of the mixer to generate sum and difference frequencies. A filter and amplifier at the output of the mixer removes the summation frequency leaving the difference frequency to the first and second multipliers.
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申请公布号 |
US5457424(A) |
申请公布日期 |
1995.10.10 |
申请号 |
US19940318940 |
申请日期 |
1994.10.06 |
申请人 |
MOTOROLA, INC. |
发明人 |
MCGINN, MICHAEL;MAIN, W. ERIC |
分类号 |
H04L27/152;(IPC1-7):H04L27/38 |
主分类号 |
H04L27/152 |
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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