发明名称 |
Methods and apparatus for frequency response analysis |
摘要 |
In a heterodyning arrangement to enable frequency response testing of a system at a high frequency F using a digital correlator capable of operation at a lower frequency F/h, an offset signal is generated at a frequency F(h-1)/h and multiplied with the output signal of the system under test. Two heterodynes result: a wanted signal at a frequency F/h, and an unwanted image signal at F(2h-1)/h. The value of h is selectable independently of a divisor N which controls derivation of the test frequency F from a frequency synthesizer operating at a frequency NF. Thus the frequency of the image signal can be arranged to avoid spurious non-zero responses in the digital correlation process at frequencies related to N.
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申请公布号 |
US4510440(A) |
申请公布日期 |
1985.04.09 |
申请号 |
US19820445791 |
申请日期 |
1982.12.01 |
申请人 |
SCHLUMBERGER ELECTRONICS (U.K.) LIMITED |
发明人 |
RYDER, ALAN |
分类号 |
G01R27/28;G01R23/16;(IPC1-7):G01R23/16 |
主分类号 |
G01R27/28 |
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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