The clock signal generating circuit

PURPOSE:To ensure the output of a clock signal having a 1:1 duty ratio by placing a notch filter between an oscillator and a waveform converting circuit and eliminating the higher harmonic component of the clock signal for reduction of this signal distortion. CONSTITUTION:An oscillator 10 is connected to a stub type notch filter 16. The filter 16 is connected to a waveform converting circuit 11, and this circuit 11 is connected to a digital circuit 12. Then the oscillator 10 transmits a signal to a microstrip line. The higher harmonic component is contained in the signal and therefore this signal is distorted. The higher harmonic component of the distorted signal is eliminated through the filter 16. Thus a sine wave signal containing the reduced distortion is acquired. The sine wave signal free from the distortion is changed into a rectangular wave by the circuit 11. Thus a rectangular wave that has the coincidence between the high and low periods and has a 1:1 duty ratio is transmitted. A clock signal having a 1:1 duty ratio can stabilize the operation of the circuit 12.