| 摘要 |
The circuitry increases the average power of the modulating signal and thus the signal-to-noise ratio. The circuitry includes a microphone, an audio amplifier, a splatter filter, a potentiometer, an oscillator and transmitter as well as an antenna. The auido amplifier includes an operational amplifier having an input resistor coupled via a capacitor to the amplifier, and a feedback resistor coupled between the filter and the input resistor. When driven into amplitude limiting, the phase and amplitude of harmonic signals from the operational amplifier are altered by the filter. |
