| 摘要 |
The invention aims to provide a high-frequency device enable to protect circuits connected to an antenna terminal from possible intruding static electricity or high voltage noises. Diplexer 11 connected to antenna terminal 10 carries out demultiplexing or multiplexing frequency for GSM or DCS band. Circuits to process frequency for GSM and DCS band have switches 13 and 14 respectively for switching to transmit or to receive signals for diplexer 11. Switch 13 and 14 are connected to low pass filters 15 and 16 respectively to clear off higher harmonics in transmitting signals, and are connected to SAW filters 17 and 18 having respective specific pass bands. Filters 15, 16, 17 and 18 are connected to terminals 19, 20, 21 and 22 respectively. Moreover, a first end of varistor 23 is connected between antenna terminal 10 and diplexer 11 and a second end of varistor 23 is connected to ground terminal 24.
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