FREQUENCY SHIFT KEYING MODULATION CIRCUIT USING LOW SPEED DATA MODULATION

摘要

a phase detector 11 for detecting the phase of an input reference frequency; a low pass filter 12 for filtering a low frequency having the phase detected by the phase detection loop 11; a voltage-controlled oscillator 13 for converting an oscillating frequency into a control voltage of low pass the filtered signal; a program function divider 14 for dividing the oscillating frequency converted at the voltage-controlled oscillator 13 by the input frequency shift data and inputting it to the phase detector 11; a divider 15 for dividing the oscillating frequency converted at the voltage-controlled oscillator 13 by N; a local oscillator 16 for converting the oscillating frequency in the loop; a mixer 17 for mixing the oscillating frequency converted at the local oscillator 16 and the frequency divided at the divider 15; and a band pass filter 18 for filtering the mixed signal from the mixer 17.