MODULATION SENSITIVITY COMPENSATION TYPE VOLTAGE CONTROLLED OSCILLATOR

摘要

PURPOSE:To secure the linearity of a voltage controlled oscillator apparently by adding a polygonal line approximation circuit to the voltage controlled oscillator. CONSTITUTION:A polygonal line approximation circuit 2 is provided to a voltage controlled oscillator as a pre-stage circuit of the voltage controlled oscillator 1. The polygonal line approximation circuit 2 consists of basic configuration of a V-I(voltage-current) converter 3 at a pre-stage, a linearity compensator 4 in its middle stage and an I-V (current-voltage) converter 5 in its post-stage. Since the polygonal line approximation circuit 2 is added in this way, the linearity in the modulation sensitivity in the voltage versus frequency characteristic is improved, the lock-in range is considerably extended and the application scope of the automatic frequency control circuit is expanded.