| 摘要 |
<p>PURPOSE: To provide the phase detecting circuit for rader receiver with which the video I signal of video Q signal of mutually orthogonal and well-balanced digital signals can be provided with simple configuration. CONSTITUTION: A received signal IF converted to an intermediate frequency is limited to a frequency band f1 F±(fA/8) by a band pass filter 21. Next, that signal is converted to a digital received signal DIF by an A/D converter 22, a 90 deg. phase rotated digital received signal 90 deg. DIF is prepared by a hilbert transformer 25, and a digital received signal 0 deg. DIF whose timing is matched with the output of the Hilbert transformer 25 is prepared by a delay circuit 24. The video I signal and video Q signal of mutually orthogonal signals are prepared by decimeters 26 and 27. It is not necessary to conventionally use the A/D converter for both I and Q channels and the video I signal and video Q signal of well-balanced digital signals can be provided by the simple configuration unnecessitating any adjustment circuit.</p> |
