1,721,160 research outputs found
A mathematical modelling approach for the large-signal performance prediction of microwave electron devices
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A computer-oriented design method for large-signal microwave transistor amplifiers
No full textA method for the design of large-signal microwave amplifiers using a quasi-black-box transistor model is described. It is based on design maps, drawn on the basis of a suitable large-signal mathematical model of the transistor, which permit a straightforward search for the load reflection coefficient which provides maximum saturated output power or, alternatively, a good compromise between conflicting gain and output power requirements. This method, besides being accurate enough for most amplifier design problems, is also quite simple to apply in practice, since the numerical computations involved can easily be programmed on a desk-top personal computer. The design procedures were implemented in a Fortran program running on an IBM AT personal computer, requiring 350-kB RAM and a very short (a few minutes) total computing time. The good agreement between predicted and measured performance confirms the validity of the method
A design method for DR-stabilized MESFET oscillators
Full text linkIn this paper a method is proposed for the design of DR-stabilized MESFET oscillators where several diferent design objectives, associated both to stability and output power, can simultaneously be taken into account. First, stability and self-starting capability of an oscillator are related to suitable performance indexes which are defined in the paper. Then an efficient procedure aimed at searching for an optimal compromise between opposing design requirements is described. The validity of the whole procedure and the performance indexes introduced has been investigated by considering the design of a microstrip parallel-feed back DR oscillator using a medium power GaAs MESFET
A Harmonic-Balance-oriented modeling approach for microwave electron devices
No full textA technology-independent model of microwave electron devices, the Nonlinear Integral Model, is proposed. This model is rigorously derived from the Volterra series under mild assumptions valid for most types of electron devices and is particularly suitable for circuit analysis based on harmonic-balance techniques. Moreover, it makes it possible to compute the large-signal response of an electron device directly in terms of data obtained by physics-based numerical simulations. The validity of the model is confirmed both by simulation and by experimental results
A computationally efficient unified approach to the numerical analysis of the sensitivity and noise of semiconductor devices
Full text linkThe authors present a computationally efficient unified approach to the numerical simulation of sensitivity and noise in majority-carrier semiconductor devices that is based on the extension to device simulation of the adjoint method for sensitivity and noise analysis of electrical networks. Sensitivity and device noise analysis based on physical models are shown to have a common background, since they amount to evaluating the small-signal device response to an impressed, distributed current source. This problem is addressed by means of a Green's function technique akin to Shockley's impedance field method. To allow the efficient numerical evaluation of the Green's function within the framework of a discretized physical model, inter-reciprocity concepts, based on the introduction of an adjoint device, are exploited. Examples of implementation involving GaAs MESFETs are discusse
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