| 摘要 |
PURPOSE:To obtain a stable oscillation performance by providing an amplifier to amplify the output signal of a voltage control oscillator up to a constant level. CONSTITUTION:A phase comparator 102 compares the phase of the reference input signal inputted to a reference signal input terminal 101 and the phase of the output signal of a voltage control oscillator 105 and outputs a phase error signal. The phase error signal is converted to the control voltage necessary to the input of the voltage control oscillator 105 by a loop filter 103. A sweeping oscillator 104 forcibly sets the direct current input voltage of the voltage control oscillator 105 to near the range of the pull-in setting. Regardless of the level of the same output signal, the output signal of the voltage control oscillator 105 is amplified up to the constant level with an amplifier 106. Thus, the stable oscillation performance can be obtained. |
