发明名称 |
Frequency measuring circuit in a passive radar receiver |
摘要 |
Passive frequency measuring circuit comprising a number of frequency discriminators to obtain a digital code representing the frequency of an applied r.f. signal. Each discriminator is tuned to different frequency ranges, and provided with a plurality of similar frequency analysers for the phase detection of the applied r.f. signal passed through different delay lines. As each discriminator delivers an ambiguous code at the boundaries of its characteristic, a digital filter is incorporated to resolve the ambiguity. If such an ambiguity is established, an adjoining discriminator is activated to deliver information for obtaining a digital code representing an unambiguous frequency value.
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申请公布号 |
US4188628(A) |
申请公布日期 |
1980.02.12 |
申请号 |
US19780898460 |
申请日期 |
1978.04.20 |
申请人 |
N V HOLLANDSE SIGNAALAPPARATEN |
发明人 |
LANGERAAR, HUIBERT B;VAN ROOIJEN, GERRIT |
分类号 |
G01R23/00;G01S7/02;(IPC1-7):G01S9/02 |
主分类号 |
G01R23/00 |
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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