Title :
Large signal RF behaviour of low supply voltage (<3.5 V) bipolar junction transistors
Author :
Huizing, H.G.A. ; van Rijs, F. ; Magnée, P. H C ; Hartskeerl, D.M.H.
Author_Institution :
Philips Res. Lab., Eindhoven, Netherlands
Abstract :
Test devices with collector doping and thickness variations have been made to investigate conventional double poly bipolar junction transistors (BJTs) for use in RF power amplifiers at supply voltages down to 2 V. Measurements and simulations have been performed on power efficiency, gain and linearity. It has been found that efficiencies saturate at about 62-65% (at 1.8 GHz) for thin collectors. From comparison with harmonic balance simulations, this effect is explained by observing that efficiency is limited by hard saturation (which is the same for all devices presented in this paper) rather than by the current and gain limiting “quasi-saturation” effect which dominates in devices with thicker epilayers. Two-tone intermodulation measurements indicate that BJTs are suitable for use in handsets based on e.g. Enhanced Datarate for GSM Evolution (EDGE)
Keywords :
UHF bipolar transistors; UHF power amplifiers; cellular radio; circuit simulation; doping profiles; intermodulation measurement; low-power electronics; semiconductor device measurement; semiconductor device models; telephone sets; 1.8 GHz; 2 V; 3.5 V; 62 to 65 percent; BJT measurements; BJT simulations; BJTs; EDGE handsets; Enhanced Datarate for GSM Evolution; RF power amplifiers; bipolar junction transistors; collector doping variations; collector thickness variations; current/gain limiting quasi-saturation effect; double poly bipolar junction transistors; efficiency; efficiency saturation; epilayer thickness; gain; handsets; hard saturation; harmonic balance simulations; large signal RF behaviour; linearity; power efficiency; supply voltage; test devices; thin collectors; two-tone intermodulation measurement; Doping; Gain measurement; Low voltage; Power amplifiers; Power measurement; Power supplies; RF signals; Radio frequency; Radiofrequency amplifiers; Testing;
Conference_Titel :
Bipolar/BiCMOS Circuits and Technology Meeting, 2000. Proceedings of the 2000
Conference_Location :
Minneapolis, MN
Print_ISBN :
0-7803-6384-1
DOI :
10.1109/BIPOL.2000.886178