发明名称 |
MODULATION MEASURING CIRCUIT |
摘要 |
<p>A circuit responsive to an input signal having an unspecified frequency for converting it to a predetermined and constant means frequency, and particularly suitable for incorporation in a modulation measuring instrument, comprises a sampling mixer controlled by a variable frequency oscillator for sampling the input signal to produce an intermediate signal. The mean frequency of the intermediate signal is then compared with a reference representing a predetermined frequency value whereby to produce an error signal, and means responsive to the error signal adjusts the frequency of the oscillator in such a direction as to tend to hold the mean value of the frequency of the intermediate signal at the predetermined frequency value while preserving therein variations in amplitude and/or frequency due to amplitude and/or frequency modulation.</p> |
申请公布号 |
CA1019405(A) |
申请公布日期 |
1977.10.18 |
申请号 |
CA19750227372 |
申请日期 |
1975.05.20 |
申请人 |
RACAL INSTRUMENTS LIMITED |
发明人 |
GITTINS, DEREK R.;GREGORY, MICHAEL D. |
分类号 |
G01R23/14;G01R29/06 |
主分类号 |
G01R23/14 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|