Abstract: In some applications of power amplifiers, a prescribed or given amount of distortion is permissible under many operational conditions, as long as lesser amounts of distortion are available upon command. It has been ascertained as a part of the present invention that, by reducing the bias current in one or more of the output stages of a power amplifier, acceptable distortion specifications can be maintained under conditions of low power consumption and low output power requirements while retaining the ability to have more demanding linearity requirement specifications by increasing the bias current to a more linear portion of the I-V (current-voltage) curve and optionally providing increased output signal power. The bias condition of reduced power results in a conservation of electrical power requirements, a reduction of heat and temperature problems within the amplifier enclosure and accordingly an increase in component life and circuit reliability.

Abstract: The present inventive concept combines two signals, each representative of a portion of a single signal, wherein the two signals have different non-linear slopes, and produces a single linearly changing output signal indicative of the combination. This circuit is specifically used in combination with the feedback loop of a delayed automatic gain control circuit to detect the signal level applied to the gain control circuit and to provide a linearly changing output signal representative of the decibel value of the signal applied to the automatic gain control circuit. This is accomplished by linearizing the two different signals independently, and establishing a maximum value for one signal, a minimum value for the other signal, and summing these in conjunction with a reference to produce a single composite linearly changing signal.