| 摘要 |
PROBLEM TO BE SOLVED: To reduce degradation of side lobe characteristics and BER characteristics, which are the evaluation criteria of a digital transmitter, by reducing the influence of the length of an IF cable on a digital signal. SOLUTION: The attenuation quantity in an IF cable is made explicit from the degraded portion of DC voltage superposed on the IF signal to be supplied from a control part to a high frequency part. The reference voltage of AGC (automatic gain control) can be set so that a signal level becomes appropriate in the CPUs of the control part and the high frequency part on the basis of the information, and the degradation of the side lobe characteristics and the BER characteristics is reduced to the utmost by properly setting the respective AGC circuits of the control part and the high frequency part. COPYRIGHT: (C)2003,JPO
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