| 摘要 |
<p>PROBLEM TO BE SOLVED: To simplify double band design and to prevent the expansion and cost raise of equipment by respectively equalizing the first frequency of a first oscillator signal and the second frequency of a second oscillator signal with respect to radio operation in both first and second frequency bands. SOLUTION: On a reception circuit, an RF head 100 receives an incoming signal 102 and transmits it through mixers 110 and 114 to a demodulator 123. The mixer 110 inputs a signal 109 from a main synthesizer 108 and the frequency of the signal 109 is equal with respect to the operation in both 800 MHz and 1900 MHz bands. The mixer 114 inputs a signal 115 from a channel synthesizer 116 and mixes it. Then, both the main synthesizer 108 and channel synthesizer 116 generate a filtering IF signal 119 at the same frequency in both the 800 MHz and 1900 MHz bands. Similarly, a transmission circuit generates a transmission signal 103 from a modulator 129 through mixers 134 and 111.</p> |
