| 摘要 |
<P>PROBLEM TO BE SOLVED: To execute the control of starting or stopping the operation of a noise cancellation part by detecting and determining the input signal level of a weak electric field at a high speed. Ž<P>SOLUTION: A high frequency reception part is provided with a signal level determination circuit 149 for determining the input signal level to an input terminal 117 by comparing a second AGC voltage with a predetermined reference voltage and the noise cancellation part 127 connected between an antenna 119 and an amplifier 139 for noise-canceling noise signals which jump into the antenna 119, and the noise cancellation part 127 is controlled on the basis of the determined result of the signal level determination circuit 149. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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