| 摘要 |
PROBLEM TO BE SOLVED: To frequency-convert a plurality of kinds of received signals different in frequency band into intermediate signals using a little number of oscillators and also demodulate them. SOLUTION: A local oscillator block 10 has a first oscillation frequency- variable oscillator 12 and a second mixer 14. If (n) is a positive integer not less than 1, the frequency F3 of an intermediate frequency signal is set in a range from F3=((F1min-F2min)/2)/(n+1) to (F1max-F2max)/2)/(n+1). An oscillation signal of the first oscillator 12 and an n-multiple signal of a second local oscillation signal are inputted to the second mixer 14. Upon receipt of a reception signal in a first frequency band, the second mixer 14 outputs a first local oscillation signal, i.e., the sum of the oscillation frequency of the first oscillator 12 and the film of the n-multiple signal. Upon receipt of a reception signal in the second frequency band, it outputs a first local oscillation signal, i.e., the difference between them.
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