An approach using the microcomputer techniques to control both frequency and amplitude of the Frequency Synthesizer simultaneously is discussed.
This frequency and amplitude control system consists of phase locked loop, counter circuit, crystal oscillator, frequency doubler, automatic gain control circuit, level shifting circuit, and a few analog circuits. Variation of the frequency is effected by the phase locked loop and that of amplitude is effected by the field effect transistor.
Bandwidth of frequency is from 39.75MHZ to 47.25MHZ and its step is 0.125MHZ and is controlled by the counter using micro computer.
Maximum amplitude is 450 mVpp at plus 2V of the D+7A output and minimum is 80 mVpp at minus 2V of the D+7A output.
39.75 MHz부터 47.25 MHz까지의 사이에 있는 frequency를 0.125 MHz step으로 Micro Processor로서 control할 수 있는 Frequency Synthesizer를 만들었다.
보통의 Function Generator와 같이 amplitude를 변화시킬 수 있고 이것을 Micro Processor로써 control할 수 있게 하였다.