| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmission device which is commonly used for analog/digital systems by satisfying specification of spuriousness when the device is operated by the analog system and satisfying specification of spuriousness and side robe spectrum specification when it is operated by the digital system. SOLUTION: A transmitter is provided with a SAW filter unit which is also arranged in a receiver. When the device is operated by the analog system, a signal is prevented from passing through a SAW filter in the SAW filter unit. When the device is operated by the digital system, the signal is prevented from passing through the SAW filter in the SAW filter unit. Thus, a component in a band except for a pass band is steeply attenuated. COPYRIGHT: (C)2005,JPO&NCIPI
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