Title :
Increasing low-frequency stability margins in microwave amplifiers from experimental data
Author :
Otegi, Nerea ; Anakabe, Aitziber ; Pelaz, Joana ; Collantes, Juan-Mari ; Soubercaze-Pun, Geoffroy
Author_Institution :
Dpto. Electricidad y Electrónica, University of the Basque Country (UPV/EHU), Bilbao 48080, Spain
Abstract :
A key aspect in the robust design of microwave amplifiers is to ensure circuit stability beyond the nominal operating conditions. In this work, a method for measuring and controlling the stability margin of low-frequency resonances in microwave amplifiers is proposed. The approach adds an extra RF port in series with an R-C stabilization network that is connected to the amplifier bias path. The extra RF port is used to experimentally obtain the critical poles of the circuit. Then, from the obtained pole-zero map, pole-placement techniques are applied to get the R-C values that increase the stability margin of the critical resonances. In this way, the risk of running into a low frequency oscillation when amplifier conditions are varied can be significantly reduced. The complete approach is experimentally validated in a demonstrator prototype built in printed circuit board technology.
Keywords :
Circuit stability; Frequency measurement; Microwave amplifiers; Microwave circuits; Oscillators; Stability analysis; Circuit stability; identification; measurement; poles and zeros; stabilization networks;
Conference_Titel :
Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International
Conference_Location :
Montreal, QC, Canada
Print_ISBN :
978-1-4673-1085-7
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2012.6259587