Very high-frequency small-signal equivalent circuit for short gate-length InP HEMTs

A small-signal equivalent circuit for short gate-length InP high electron-mobility transistors (HEMTs) operating at very high frequency (HF) is proposed. First, the extrinsic parameters of the equivalent circuit are determined using a cold HEMT, but without forward gate bias. Then the intrinsic parameters of the equivalent circuit are extracted, including the frequency dependence of some of them. A fast and accurate method based on least-squares regressions is presented to obtain the extrinsic and intrinsic parameters from measured S-parameters. The improved equivalent circuit accurately fits the S-parameters of 0.25-/spl mu/m InP HEMTs over the 500-MHz up to 40-GHz measurement bandwidth, for all gate-to-source and drain-to-source voltages.

[1]  R. T. Webster,et al.  Determination of InP HEMT noise parameters and S-parameters to 60 GHz , 1995 .

[2]  D. J. Skellern,et al.  Modelling drain and gate dependence of HEMT 1-50 GHz, small-signal S-parameters, and d.c. drain current , 1995 .

[3]  Ignasi Corbella,et al.  Instantaneous model of a MESFET for use in linear and nonlinear circuit simulations , 1992 .

[4]  H. Fukui,et al.  Determination of the basic device parameters of a GaAs MESFET , 1979, The Bell System Technical Journal.

[5]  H.-O. Vickes.  Determination of intrinsic FET parameters using circuit partitioning approach , 1991 .

[6]  R. Anholt,et al.  Measurement and analysis of GaAs MESFET parasitic capacitances , 1991 .

[7]  M. Berroth,et al.  Broad-band determination of the FET small-signal equivalent circuit , 1990 .

[8]  P. L. Hower,et al.  Current saturation and small-signal characteristics of GaAs field-effect transistors , 1973 .

[9]  Naofumi Okubo,et al.  GaAs MESFET characterization using least squares approximation by rational functions , 1993 .

[10]  S. Weinreb,et al.  A note on experimental determination of small-signal equivalent circuit of millimeter-wave FETs , 1993 .

[11]  D. J. Skellern,et al.  A technique for modelling S-parameters for HEMT structures as a function of gate bias , 1992 .

[12]  Manfred Berroth,et al.  High-frequency equivalent circuit of GaAs FETs for large-signal applications , 1991 .

[13]  R. Anholt,et al.  Equivalent-circuit parameter extraction for cold GaAs MESFET's , 1991 .

[14]  Mike Golio,et al.  Direct extraction of GaAs MESFET intrinsic element and parasitic inductance values , 1990, IEEE International Digest on Microwave Symposium.

[15]  G. Dambrine,et al.  A new method for determining the FET small-signal equivalent circuit , 1988 .