摘要 |
A low-cost local oscillator of a spectrum analyzer, in which linearity is corrected during the frequency scanning of a voltage-controlled oscillator. To accomplish this object, a linearity correction circuit (78) for giving a definite gradient to the control voltage versus oscillation frequency characteristic is interposed between a ramp generator (72) and a D/A converter (74), and the output of the D/A converter (74) is applied to the voltage-controlled oscillator in the local oscillator (30).
|