| 摘要 |
PROBLEM TO BE SOLVED: To obtain a frequency converter and a communication system for converting the frequency of an input signal transmitted on a transmission path to produce an intermediate signal before a specified section, and further converting the frequency of the intermediate signal to produce an output signal after the specified section in which a phase noise added to the output signal is reduced without using an expensive circuit element. SOLUTION: Accuracy of a circuit element having an effect on the phase noise of a local signal among circuit elements constituting local signal oscillators 106, 207 is substantially equalized in the local signal oscillators 106, 207. Consequently, an up-convert local signal and a down-convert local signal having substantially identical frequency components of phase noise are generated. An up-converter 19 generates an input signal inside building structure having a frequency corresponding to the sum of frequencies of an input up-signal and a local signal. A down-converter 20 generates an output up-signal having a frequency corresponding to the difference of frequencies between the input signal inside building structure and a local signal. |
