Title :
A microwave Doherty amplifier with programmable bias control
Author :
Berroth, Manfred ; Willeke, Jan ; Dettmann, I.
Author_Institution :
Inst. of Electr. & Opt. Commun. Eng., Univ. Stuttgart, Stuttgart
Abstract :
This paper investigates the adaptive bias control of a microwave Doherty amplifier using a programmable logic device. The gate bias of the peaking amplifier is controlled by the magnitude of the envelope of the RF input signal, which is digitized by a logarithmic detector. Compared with a class C peaking amplifier the peak output power at the 1 dB compression point is increased from 56 W to 85 W at 1.9 GHz. The power added efficiency improves from 26.9% to 31.5% at 6 dB back-off.
Keywords :
UHF power amplifiers; microwave power amplifiers; programmable logic devices; RF input signal; adaptive bias control; gate bias; logarithmic detector; microwave Doherty amplifier; peaking amplifier; programmable bias control; programmable logic device; Adaptive control; Envelope detectors; Microwave amplifiers; Microwave devices; Power amplifiers; Programmable control; Programmable logic devices; RF signals; Radio frequency; Radiofrequency amplifiers;
Conference_Titel :
Circuits and Systems, 2008. MWSCAS 2008. 51st Midwest Symposium on
Conference_Location :
Knoxville, TN
Print_ISBN :
978-1-4244-2166-4
Electronic_ISBN :
1548-3746
DOI :
10.1109/MWSCAS.2008.4616923
