Mechanisms determining third order intermodulation distortion in algaas/gaas heterojunction bipolar transistors Article

Samelis, A, Pavlidis, D. (1992). Mechanisms determining third order intermodulation distortion in algaas/gaas heterojunction bipolar transistors . IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, 40(12), 2374-2380. 10.1109/22.179904

cited authors

  • Samelis, A; Pavlidis, D

authors

abstract

  • The third order intermodulation distortion (IMD3) mechanisms of HBT's are analyzed using Volterra Series theory. A T-equivalent circuit is used for the large-signal model of the HBT. The third order nonlinear currents generated by the device nonlinearities are evaluated for this purpose and current cancellation is discussed. It is found that, even though the Cje and gje related currents do not show pronounced cancellation, the total base-emitter current and the total base-collector current cancel partially. Second harmonic loading is ad-dressed in view of IMD3 optimization while, at the same time, maintaining high gain through conjugate matching at the fundamental frequency. IMD3 is very sensitive to the nonlinear currents generated by gje and a. Optimum IMD3 occurs at high second harmonic reflection coefficients corresponding to open load conditions. Finally, minimum and maximum IMD3 occurs for second harmonic load reflection coefficient phases close to analogous extremes of the dominant nonlinear current of the device. © 1992 IEEE

publication date

  • January 1, 1992

published in

Digital Object Identifier (DOI)

start page

  • 2374

end page

  • 2380

volume

  • 40

issue

  • 12