Title :
High-efficiency low-voltage-stress Class-EF PA with extended maximum operating frequency
Author :
Thian, Mury ; Fusco, Vincent
Author_Institution :
ECIT Inst., Queen´´s Univ. Belfast, Belfast, UK
Abstract :
The Class-EF power amplifier (PA) introduced recently has a peak switch voltage much lower than the well-known Class-E PA. However, the value of the transistor output capacitance at high frequencies is typically larger than the required Class-EF optimum shunt capacitance. As a result, softswitching operation that minimizes power dissipation during OFF-to-ON transient cannot be achieved at high frequencies. A novel Class-EF topology with transmission-line load network proposed in this paper allows the PA to operate at much higher frequencies without trading the other figures of merit. Closed-form formulations are derived to simultaneously satisfy the Class-EF impedances requirement at fundamental frequency, all even harmonics, and the first two odd harmonics as well as to provide matching to 50Ω load.
Keywords :
power amplifiers; class-E PA; class-EF impedances requirement; class-EF optimum shunt capacitance; class-EF power amplifier; class-EF topology; extended maximum operating frequency; high-efficiency low-voltage-stress class-EF PA; peak switch voltage; power dissipation; soft switching operation; transistor output capacitance; Capacitance; Harmonic analysis; Inductance; Power amplifiers; Power generation; Switches; Transistors; Class E; Class EF; harmonic tuning; high efficiency; low voltage stress; power amplifiers; switching amplifiers; transistor circuits; transmission lines;
Conference_Titel :
Microwave Conference (GeMIC), 2011 German
Conference_Location :
Darmstadt
Print_ISBN :
978-1-4244-9225-1
Electronic_ISBN :
978-3-9812668-3-2