Polar SiGe class E and F amplifiers using switch-mode supply modulation

Two integrated polar supply-modulated class E and F power amplifiers (PAs) in 0.18-[micro]m SiGe BiCMOS process are presented. The amplifiers are used to transmit GSM-EDGE signals with an envelope dynamic range of 11 dB and a frequency range of 880-915 MHz. The amplifiers use switch-mode dc--dc buck converters for supply modulation, where sigma--delta ([SUMMATION][DELTA]M), delta ([DELTA]M), and pulsewidth modulation are used to modulate the PA amplitude signal. A framework has been developed for comparing the three switching techniques for EDGE implementation. The measurement results show that [DELTA]M gives the highest efficiency and lowest adjacent channel power, providing class E and F PA efficiencies of 33% and 31%, respectively, at maximum EDGE output power. The corresponding class E and F finearized amplifiers' output spectra at 400-kHz offset are -54 and -57 dBc, respectively. Index Terms--EDGE, polar modulation, power amplifiers (PAs), switching amplifiers. Digital Object Identifier 10.1109/TMTT.2007.895407