International Journal of Microwave and Wireless Technologies vol:3 issue:3 pages:329-338
Burst Mode operation is proposed as an eﬃciency improving technique for power ampliﬁers. The core idea is to modulate the amplitude of the envelope signal into a series of square wave pulses such that the width of the signal burst or the total amount of pulses are varied according to the envelope. The phase information is still contained by the timing of the pulses. This work presents the eﬃciency and linearity analysis of Burst Mode RF PAs. In addition, the eﬃciency performance is compared when the Burst Mode RF PA is connected to a wideband load or a narrowband ﬁlter. It is shown that Burst Mode PAs are more eﬃcient than the conventional Class B PAs. To achieve an even more favorable eﬃciency, a transmission line is inserted between the output of the switching RF PA and the ﬁlter to improve the ﬁlters impedance characteristic. Additionally, the eﬃciency and linearity of the Burst Mode PA with and without transmission line has been studied and simulated thoroughly. To demonstrate the validity of the eﬃciency formulas and linearity considerations, a PCB-mounted Burst Mode PA using a LDMOS transistor was fabricated. Measurements show a peak eﬃciency of 78% and 28.8dBm of output power.