| 摘要 |
PURPOSE:To reduce the number of mixers by frequency-converting simultaneously objective transmission signals while permitting the mixers to sequentially generate LO signals for other mixers from two signals of different frequencies. CONSTITUTION:Signals (center frequency fIF) 21a-21d are respectively multiplexed in mixers 202a-202d with signals which an N distributor 201 has divided the signals (frequency f1) 20a from a signal generator 200. Signals from the mixer 202a are frequency-converted in a mixer 203a with a signal (frequency fL) 20b as the LO(local oscillation) signal. A BPF for RF 205a samples components whose center frequencies are fL-fIF, and a BPF for LO 206a samples components whose center frequencies are fL-fl, whereby a signal from the BPF 206a turns into the LO signal of a mixer 203b. Thus, signals whose center frequencies are fL-nfl-fIF are respectively outputted from BPF for RF 205a-205d (n is integer). Thus, the number of the mixers can considerably be reduced.
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