| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a transmitter-receiver capable of transmitting/receiving RF signals at least in two frequency bands. SOLUTION: The transmitter-receiver based on direct conversion is used and mixed frequency bands are generated with the help of the same synthesizer. When the transmitter-receiver is driven in mutually separated frequency bands, it is preferable to generate mixed frequency bands (211, 231, 261, and 281) by dividing the output signal of the synthesizer by mutually different divisors. When the transmitter-receiver is driven in mutually adjacent frequency bands, a divisor P to be used for the feedback in the synthesizer is preferably changed (248).</p> |
