A new tool to aid in the design and optimization of millimeter-wave monolithic circuits - A distributed and nonlinear model of an FET

The paper presents a rigorous and systematic methodology for developing a distributed and nonlinear model of an FET, which is easy to use in nonlinear simulators employing harmonic balancing techniques. This model is obtained on the basis of knowledge of the classical nonlinear localized equivalent circuit and the geometrical dimensions of the component. The transistor is modeled by N identical sections, each of which includes a nonlinear quadripole that simulates the field-effect phenomenon; it is inserted between two linear octopoles that simulate interelectrode couplings and phase effects. The two-dimensionality of the model makes it possible to characterize an FET in a wide frequency band, beyond 100 GHz.