Michael Lee David

US Patent:

56358709, Jun 3, 1997

Filed:

Aug 15, 1995

Appl. No.:

8/515523

Inventors:

Michael David - Woodland Hills CA

International Classification:

H03F 366

US Classification:

330 52

Abstract:

A method and apparatus is provided for amplifying electronic signals in a linear fashion while maintaining DC power efficiency. In one embodiment, the invention comprises a coupler receiving an input signal and connected to a non-linear amplifier. A tone generator is also connected to the coupler, and generates a tone signal at a selected frequency. The coupler combines the tone signal and an input signal and provides the combined signal to the amplifier. The combined signal is amplified and bandpass filtered to remove spectral by-products. The power of the tone wave generator signal is selected so as to cause the nonlinear amplifier to operate near its saturation point but in a linear region. The effect is to linearize the operation of the nonlinear amplifier, while simultaneously minimizing the presence of intermods and maintaining a relatively high level of DC power efficiency. Various modifications are also disclosed, wherein the amplitude of the tone signal is adjusted according to the power level of the input and/or output signal.