Progress In Electromagnetics Research C
ISSN: 1937-8718
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By T. T. Thein, C. L. Law, and K. Fu

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A unilateral circuit model, which precisely predicts small signal response over a wide range of frequencies and bias points, is quantitatively analyzed and presented. The shortfall of current unilateral assumption and transformation technique is presented. A complete and explicit analysis is provided to develop a compact unilateral circuit model. The model is intended to predict input reflection, forward transmission and output reflection coefficients over wide range of frequencies. The technique is validated by transforming bilateral a small signal model of 3 x 3 μm x 40 μm, InGaP/GaAs HBT into its unilateral equivalent over the frequency range of 250 MHz to 30 GHz. The accuracy of the technique is corroborated at various bias conditions; collector current from 3 mA to 150 mA and collector-emitter voltage from 1 V to 5 V. Simulated results show very good agreement between small signal responses of transformed unilateral and bilateral circuit models.

T. T. Thein, C. L. Law, and K. Fu, "250 MHz to 30 GHz , Unilateral Circuitmodel for Ingap/GaAs Hbt," Progress In Electromagnetics Research C, Vol. 26, 1-12, 2012.

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