Title :
Reduction of UHF power transistor distortion with a nonuniform collector doping profile
Author :
Van Noort, Wibo D. ; De Vreede, Leo C N ; Jos, H.F.F. ; Nanver, Lis K. ; Slotboom, Jan W.
Author_Institution :
Dept. of Electron. Eng., Delft Univ. of Technol., Netherlands
fDate :
9/1/2001 12:00:00 AM
Abstract :
The linearity of a class-A, bipolar UHF power transistor is investigated. The device is intended for transmission of signals with multiple (TV) channels. Mixing between the various channels must be suppressed, which makes linearity an important parameter. This paper presents a novel approach, where process technology is specifically optimized to minimize distortion. It is shown that particularly the nonlinear collector-base capacitance strongly affects the linearity of this type of device. With a modified collector-base doping profile, the capacitance is manipulated. A nonuniform profile is introduced that significantly reduces third-order intermodulation. The profile consists of an arsenic doped spike that is grown epitaxially into the (otherwise) lightly doped collector. This reduces the bias dependence of Ccb and improves the tradeoff between linearity and breakdown or ruggedness. The reduction in third-order intermodulation is demonstrated both experimentally and by mixed-level MDS/MAIDS simulations
Keywords :
UHF bipolar transistors; doping profiles; intermodulation distortion; power bipolar transistors; Si:As; arsenic doped spike; bias dependence; breakdown voltage; class-A bipolar UHF power transistor; epitaxial growth; lightly doped collector; linearity; mixed-level MDS/MAIDS simulation; multiple TV channels; nonlinear collector-base capacitance; nonuniform collector doping profile; process technology; ruggedness; signal transmission; third-order intermodulation distortion; Capacitance; Circuit simulation; Doping profiles; Electronic components; Laboratories; Linearity; Nonlinear distortion; Power transistors; Radio frequency; TV;
Journal_Title :
Solid-State Circuits, IEEE Journal of
