Inventors:
John Sevic - Los Gatos CA
Khan M. Salam - Livermore CA
Assignee:
Tropian, Inc. - Cupertino CA
International Classification:
H03F 126
Abstract:
High efficiency DC to RF conversion with use of active harmonic insertion is provided for power amplification over a wide dynamic range of input signal level. Specifically, a power amplifier device including at least a final amplification stage is operated to receive an input signal of a fundamental frequency. A drive signal is produced which includes a fundamental signal component of the fundamental frequency and at least one harmonic signal component of a harmonic frequency that is substantially an integer multiple of the fundamental frequency, wherein relative phase shift and relative amplitude of the components are controlled over at least an order of magnitude of dynamic range of the input signal. As the signal level of the input signal decreases (or increases), the desired proportion of signal levels is maintained between the components. The drive signal is provided to the power amplifier device, and in response to the drive signal, an amplified output signal is produced at the final amplification stage.