| 摘要 |
PURPOSE: To transmit and receive radio waves in two different frequency bands with better sensitivity. CONSTITUTION: A LC parallel resonance circuit 3 is connected in series to the power feeder side of an antenna conductor unit 2. The antenna conductor unit 2 has a configuration, which resonates with a frequency slightly lower than the designated center frequency for the upper frequency band out of two frequency bands for transmission/reception. The LC parallel resonance circuit 3 comprises a configuration which resonates with a frequency almost the same as the designated center frequency for the lower frequency band out of two frequency bands for transmission/reception, and can give a capacity, by which the antenna conductor unit 2 resonates with the designation center frequency for the upper frequency band, to the antenna conductor unit 2. A circuit for switchover between the upper and the lower frequency bands becomes unnecessary. |
