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 C/sub cb/ 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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.