RF I-V Waveform Measurement and Engineering - the unifying link between transistor technology, circuit design and system performance
Microwave power amplifier performance, output power, conversion efficiency and linearity, etc., is significantly influenced by the terminal voltage and current time varying waveforms that develop at the transistor terminals; terminal waveforms are the unifying theoretical link between transistor technology, circuit design and system performance. Thus waveform engineering should be a major objective driving the power amplifiers design flow. However, in practice power amplifier design, while waveform engineering may be a guiding principle, the lack of appropriate RF waveform measurements tools has hindered its direct application at microwave frequencies. However, the past 10 years has seen the development of a number of RF characterization systems capable of measuring RF voltage and current waveforms. Coupling such systems with impedance control hardware also enables experimental control (Engineering) of these terminal RF waveforms during measurements; thus providing a practical RF Waveform Measurement & Engineering solution. This lecture will discuss these emerging systems and show they are now finally enabling practical waveform engineering to be directly undertaken within the power amplifier design flow. Design support can involve either direct utilization of the measurement system in the design investigation/evaluation loop, or indirect use by providing CAD accessible datasets.