A non‐linear and distributed modelling procedure of fets

This paper describes a rigorous and systematic procedure to derive a non-linear distributed FET model that can easily be implemented in CAD routines of simulators based on harmonic balance techniques. The new model is derived from a knowledge of the conventional linear lumped equivalent circuit, from non-linear current sources extracted from pulsed measurements, and from the physical dimensions of the FET. For fundamental and harmonic frequencies, the FET is modelled by N identical cells. Each cell is made up of a non-linear two-port section inserted between two linear four-port sections that simulate the coupling and the distributed effects along the electrodes of the FET in the width direction only. This non-linear distributed scaling approach to FET modelling has been applied to the analysis of a submicrometre-gate GaAs FET at millimetre-wave frequencies, and the results were compared with the non-linear lumped element approach. This approach can be applied to other transistors used in non-linear regions at microwave and millimetre-wave frequencies.

[1]  Michel Aubourg,et al.  A nonlinear distributed FET-model, for millimeter-wave circuit design by harmonic balance techniques , 1990, IEEE International Digest on Microwave Symposium.

[2]  François Dupis.  Analyse temporelle et conception d'oscillateurs microondes a faible bruit de phase , 1986 .

[3]  A.S. Podgorski,et al.  Theory of traveling-wave transistors , 1982, IEEE Transactions on Electron Devices.

[4]  Y. Tajima,et al.  Design of Broad-Band Power GaAs FET Amplifiers , 1984 .

[5]  Renato G. Bosisio,et al.  Variation of gate and drain contact positions along the width of MESFETs and its influence on millimeter wave oscillator performance , 1991 .

[6]  Juan Obregon,et al.  The Spectral Balance: A General Method for Analysis of Nonlinear Microwave Circuits Driven by Non-Harmonically Related Generators , 1987, 1987 IEEE MTT-S International Microwave Symposium Digest.

[7]  C. Yuen,et al.  DISTRIBUTED GaAs FET CIRCUIT MODELFOR BROADBAND AND MILLIMETER WAVEAPPLICATIONS , 1984 .

[8]  M. Aubourg,et al.  Finite Element Analysis of Lossy Waveguides-Application to Microstrip Lines on Semiconductor Substrate , 1983 .

[9]  M. Toda,et al.  Nonlinear lattice and soliton theory , 1983 .

[10]  Ce-Jun Wei.  Novel design of travelling-wave FET , 1983 .

[11]  L. Escotte,et al.  Semidistributed model of millimeter-wave FET for parameter and noise figure predictions , 1990 .

[12]  K.-H. Kretschmer,et al.  Coupled-mode analysis of travelling-wave MESFETs , 1985 .

[13]  J. P. Mondal.  Distributed scaling approach of MESFETs and its comparison with the lumped-element approach , 1989 .

[14]  W. Heinrich.  High-frequency MESFET noise modeling including distributed effects , 1989 .

[15]  W. Heinrich,et al.  Field-theoretic analysis of wave propagation on FET electrodes including losses and small-signal amplification , 1985 .

[16]  P. H. Ladbrooke.  Some effects of wave propagation in the gate of a microwave m.e.s.f.e.t. , 1978 .

[17]  V. Tripathi.  Asymmetric Coupled Transmission Lines in an Inhomogeneous Medium , 1975 .

[18]  W. Heinrich,et al.  Wave Propagation on MESFET Electrodes and its Influence on Transistor Gain , 1987 .