| 摘要 |
PROBLEM TO BE SOLVED: To prevent an antenna tuning point of the radio call receiver from being deviated due to change in passage of time or mechanical shock and to obtain a best antenna tuning point with respect to all channels in a frequency band. SOLUTION: A circuit, consisting of series connection circuit of varactor diodes CR1, CR2 with opposite polarity, is provided between ground an other terminal of an antenna 1. An RSSi (electric field strength) signal obtained from a demodulation section 3 is converted into a digital signal by an A/D converter 42, and the signal is given to a CPU 41. The CPU 41 is configured so as to provide a bias voltage to the varactor diodes, thereby maximizing the capacitor and holding a best point. |
