Direct extraction technique of π‐topology small‐signal equivalent circuit model for Si/SiGe heterojunction bipolar transistor

Abstract

A developed direct extraction technique of small‐signal π‐topology Small signal equivalent circuit model for Si/SiGe heterojunction bipolar transistor is presented.The intrinsic model parameters are analytically extracted. The extraction procedure is performed using new set of exact equations that do not need numerical fitting, special polarization of the device or any kind of post processing. Flat frequency response of the extracted parameters is obtained. Excellent agreement is noticed between S‐parameters measurements and its simulated counterpart using the extracted model in the frequency range from 40 MHz to 20 GHz at different bias conditions. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:584–589, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26635

Wideband analytical extraction technique of π‐equivalent circuit model for Si/SiGe heterojunction bipolar transistor in BICMOS process

“…The available previous few works that tackle extraction of π-topology model of the Si/SiGe HBT devices problem analytically are introduced in [13][14][15][16][17]. Special polarisation for the device, frequency approximations and least square fit are needed to extract the model parameters [13,16].…”

“…On another note, it is important to incorporate the substrate effect into the model to match S 22 parameter measurements, especially at high frequency. However, it is not considered in the extraction techniques that are published in [14,15,17]. Bias independent emitter resistance is not included in the model [14,15] and consequently the model behaviour is not accurate beyond 20 GHz.…”