| 摘要 |
PURPOSE:To reduce a variable capacity diode by superposing a loop filter output and a modulating signal, and inputting them to a voltage control oscillator. CONSTITUTION:A modulating signal is inputted from a terminal T3, is superposed on an output of a loop filter LFL through a correcting circuit consisting of a capacitor C5 and a resistor R2, and is inputted to a voltage control oscillator VCO from a terminal T1. This correcting circuit and the filter LFL have a characteristic of a curve 2 and a characteristic of a curve 1, respectively, therefore, a signal inputted to the oscillator VCO comes to have a flat characteristic in a prescribed band. Accordingly, a modulating signal frequency-to- frequency deviation characteristic becomes flat. |
