University of California

Nitesh Singhal

Sudhakar Pamarti

A power amplifier (PA) which improves dynamic range of previous ZVS contour-based power amplifier architectures is presented. The inventive circuit combines ZVS contour-based power amplification with a current mode digital-to-analog converter (DAC) based digital polar power amplifier. The inventive elements interoperate to provide high efficiency even at large peak power back-off levels and increased dynamic range. The invention is particularly well-suited for use in modulation schemes (e.g., WLAN/LTE/WIMAX) having large peak-to-average output power ratios. Utilizing the inventive PA in generating modulation in these systems can increase RF transmitter efficiency of by approximately two-fold.

Digital polar and ZVS contour based hybrid power amplifier

A zero-voltage-switching contour based outphasing power amplifier having two class-E power amplifiers connected in an out-phasing architecture coupled on opposite sides of a load being driven. The pair of class-E power amplifiers receive separate digital drive signals with an amount of phase difference that is adjusted based on the load. Variable capacitor arrays are coupled in parallel on the class-E power amplifiers and controlled in response to system parameters including duty cycle of the input signal. Efficiency of the power amplifier is maintained despite variation in output loading.

Growing community of inventors

Los Angeles, CA, United States of America

Nitesh Singhal