| 摘要 |
PROBLEM TO BE SOLVED: To provide radio equipment using a direct conversion system which do not exert adverse effects from the signal of a transmitting system upon a receiving system. SOLUTION: In the transmission system, a frequency Flo of a local signal to be used for the frequency conversion of a frequency converter 117 is made into (M/N).Frx by a frequency conversion circuit 119. From this Flo and a transmitting frequency Ftx, an intermediate frequency Ftxif of transmission becomes Ftxif=Flo-Ftx= (M/N).Frx-Ftx. This becomes the oscillation frequency for a second local oscillator 117. Even if Ftx+Ftxif is turned into the reception system, since Ftx+Ftxif= (M/N).Frx-Ftxif}+Ftxif=(M/N).Frix and this is different from a receiving frequency band, this will not be an interference wave for a received signal.
|
