method for frequenznachregelung and modulation of a schwingungserzeugers

摘要

The frequency control circuit has a phase locked loop producing a tuning voltage for the varactor diode in the oscillator resonant circuit. A second varactor diode (2) is connected in series or in parallel with the first varactor diode (1) and receives a constant dc voltage and a voltage derived from the tuning voltage. The gain of the loop amplifier, for amplifying the tuning voltage from the loop phase discriminator, does not require altering. The loop cut-off frequency is held constant. A compensation circuit (3) is connected at the two outputs (8,9) to two varactor diodes and at the three inputs to a constant voltage (11), to the voltage (4) derived from the tuning voltage and to the amplified tuning voltage (5). The compensation circuit comprises an RC network.