摘要 |
A Q multiplier circuit which is automatically feedback stabilized through the use of phase and gain control loops and thereby adapted for use as an amplifier and filter. In a typical embodiment, a variable gain amplifier and band pass filter are provided in a forward signal path while a phase shifter is provided in a feedback signal path. The output of the circuit is sampled and compared to a fixed reference in order to generate a gain control signal for application to the variable gain amplifier. The input signal on the forward signal path is sampled along with the signal on the feedback signal path and the phases of these samples are compared in order to generate a phase control signal for application to the phase shifter. The variable gain amplifier is controlled to maintain a predetermined power output level while the phase shifter is controlled to maintain positive feed back.
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