| 摘要 |
PURPOSE:To eliminate the apprehension of generation of spurious radiation because of interference between plural oscillators by using an output of a single oscillator after frequency-division and multiplication as a reference comparison frequency of three kinds of PLL circuits. CONSTITUTION:A local oscillating frequency of a mixer M1 is formed by giving a frequency-division code for setting an upper frequency to the PLL1 in which an fR1 obtained by frequency-dividing or multiplying suitably a reference frequency fR0 is used as a reference frequency. Similarly, a frequency obtained by mixing an output which is obtained by giving a frequency-division code for a lower frequency setting to the PLL2 taking an fR2 obtained from the frequency- division or multiplication of the frequency fR0 as the reference frequency with an output of a carrier oscillator BFO at a mixer M3 and then mixing the mixed result with a frequency fR3 obtained by frequency-dividing or multiplying the frequency fR0 at a mixer M4, is injected to a mixer M2 of a signal circuit as a local oscillating frequency. Further, the output of the BFO is injected to a demodulator. |
