| 摘要 |
PURPOSE:To prevent the influence of variation in reception amplitude by bringing respective components of an orthogonal detector under the gain control based upon the square sum of said components. CONSTITUTION:Respective components are extracted by frequency converters 221 and 222 and further extracted by low-pass filters 251 and 252, but they contain components with the amplitude of a received modulated wave. The square-sum signal of the outputs of variable gain amplifying circuits 261 and 262 contains no modulated signal and is proportional to the square of the reception amplitude, so this is used to control a gain control amplifying circuit, thereby preventing the influence of variation in reception amplitude. Therefore, a stable detection output is obtained. |
