Doherty at Eighty – A look at Designing Today’s High-Performance RF/mW Power Amplifiers

The Doherty power amplifier (DPA) was originally introduced and described in a paper back in 1936. The DPA continues to evolve, benefitting most notably from the increasing intrusion of digital controls into the synthesis of complex digitally modulated communications signals. For example, the ability of the designer to specify the instantaneous magnitude and phase of both main and auxiliary inputs will have a disruptive impact on traditional DPA design, enabling it to perform a tuning function over extended bandwidths. This webinar will chart the reinvention of the DPA during the first decade of mobile communications and subsequent efforts to improve its Achilles heels: linearity and bandwidth.

Presenter Bio:
After Steve Cripps obtained his Ph.D. degree from Cambridge University, he worked for Plessey Research developing GaAs FET hybrid circuits. Later, he joined Watkins-Johnson’s solid state division, Loral and Celeritek, where he held engineering and management positions. During this period, he designed the industry’s first 2 to 8 and 6 to18 GHz, 1 W, solid-state amplifiers. In 1983, he published a technique for microwave power amplifier design that has been widely adopted in the industry. In 1990, he became an independent consultant, active in a variety of commercial RF product developments, including the design of several cellular telephone power amplifier MMICs. In 1996, he returned to England, where his consulting continues to focus on RF power amplifiers. Steve Cripps is an IEEE Fellow and a professorial research fellow at Cardiff University.