| 摘要 |
PROBLEM TO BE SOLVED: To perform a modulation at a low frequency and reduce the cost by commonly using the output frequency of at least one frequency synthesizer as a frequency generating source of carrier signal or local signal. SOLUTION: The outputs of a frequency synthesizer 16 with fixed frequency and a frequency synthesizer 41 with wide band variable frequency are used commonly to each channel. A channel 1 modulates the generated frequency of the fixed frequency synthesizer 16 as a carrier by a modulator 21 in this frequency, and frequency-converts it and the generated frequency of a frequency synthesizer 31 with variable narrow band frequency by a mixer 61, and passes the IF frequency signal of the sum thereof by a BPF 51. The frequency of the sum and the generated frequency of the frequency variable frequency synthesizer 41 are frequency-converted by a mixer 66, and the difference frequency f1 thereof is inputted to an adder 90. Similarly, a frequency f2 in a channel 2 and a frequency f3 in a channel 3 are inputted to the adder 90, respectively, and a multisignal of a desired level is outputted. |
