| 摘要 |
PURPOSE:To eliminate an error in setting a circuit constant and to add and subtract a high-precision frequency signal by composing all circuits of digital elements. CONSTITUTION:An oscillator 5 generates a reference frequency signal Fs, a frequency divider 6 divides its oscillation frequency Fs by N0, and counters 8 and 9 count pulses of input frequency signals F1 and F2 respectively for constant N0/Fs sec their outputs N1 and N2 are added digitally by an adder 10, whose addition output is inputted as a frequency division ratio to a frequency divider 12 to divide said reference frequency signal Fs. Pulses of this frequency-divided output Fs/(N1+N2) are counted by a counter 12 for N0/Fs sec and the counted data is held by a latch circuit 13. This data is used by a frequency divider 14 to divide the frequency of the reference frequency signal Fs, obtaining the added frequency signal. |
