CHIRP SIGNAL GENERATION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To realize a high-precision chirp signal generation circuit with a sweep oscillator by converting a pulse width into a voltage by an integrator and using an AD converter to measure this voltage and obtaining a continuous frequency error to correct the frequency of an original chirp signal. SOLUTION: A waveform shaping circuit 5 shapes the waveform of the output high frequency signal of the chirp signal to output a shaped pulse. A pulse width-voltage converter 6 generates a voltage corresponding to the pulse width of the shaped pulse. An AD converter 7 converts the output of the pulse width-voltage converter 6 into a digital code. The output of the AD converter 7 is compared with the instantaneous frequency code of the chirp signal obtained from an instantaneous frequency code generation means (circuits 10 to 13) to detect the error, and the frequency of the chirp signal is corrected in accordance with the detected instantaneous frequency error. Thus, the high-precision chirp signal is generated because of frequency control of all of the chirp signal whose frequency is continuously changed.