Design of an ultra-broadband power amplifier using distributed network synthesis

Abstract

This paper presents a methodology for designing ultra-broadband power amplifiers (PAs) based on distributed network synthesis and offers impedance matching of a power device by parasitic absorption. For the synthesis of broadband matching circuits, transfer functions of distributed networks are provided using an equal-ripple approximation, and power device models are derived using negative-image modeling. An impedance-matching circuit that absorbs power device models can be synthesized by properly choosing the minimum insertion loss (MIL) and ripple parameters of the transfer function. As an example, distributed network synthesis is applied to the design of an ultra-broadband PA, and experiments are carried out.