Diode modelling

Abstract: This paper describes about the solar photovoltaic cell and its different modelling phenomena. In solar cell modelling generally curve fitting is adopted to calculate or extract the parameter. However for better calculation of error it is not recommended to adopt the curve fitting. the objective behind this paper is to find a suitable optimization technique so that it can be applied to all other models for curve fittings. The reference parameter for evaluating the performance of the grid is taken from the data sheet provided by the manufacturer. two distinct point like zero current voltage point, maximum current voltage point has been chosen for evaluating the best performance. The simulation is performed with a commercially available multicrystalline solar PV cell for simplicity purpose and then it is compared with the reference PV characteristic to check the compatibility of the system. The paper has been organised with three parts, like the 1st part contain some basic part of solar cell modelling and followed by characteristics and model verification. Finally the parameters are extracted from the curve.

Abstract: A table-based nonlinear approach was used to predict the performance of a commercially packaged Schottky diode. Excellent results have been obtained which improve those of the analytical model provided by the manufacturer. Both models were extensively validated under DC, small and large-signal one-tone and two-tone excitations. Measurements for table-based model extraction and models validation were obtained by using a multi-tone nonlinear measurement system based on a LSNA. Time domain waveforms have once more been demonstrated as a key tool to compare large-signal models.

Abstract: The authors describe the process used to design a 28 GHz single-balanced mixer. The procedure consists of two steps, diode modelling, and analysis. The design of diode mixers for minimum conversion loss and noise figure requires knowledge of the diode impedance when pumped by a local oscillator (LO), so that the optimum matching circuit can be designed. This impedance is difficult to measure, particularly at millimetre-wave frequencies, and so the alternative is to simulate the diode operation in the time domain, using a nonlinear equivalent circuit model for the diode. The impedances at the various mixing frequencies are then obtained by analysing the voltage and current waveforms in the circuit predicted by a nonlinear analysis program. The harmonic balance method is preferred and analysis software adopting this approach is discussed. >

Abstract: This thesis investigates the sources of the significant discrepancy that exists between simulated and the measured results for the temperature dependence of bandgap voltage references. Experiments have been conducted to characterize the diodes which are the main factors contributing to the nonlinearity in the temperature dependence of bandgap reference circuits. Challenges involved in the modelling of the diodes suitable for predicting the performance of circuits which extract the bandgap voltage are discussed. Model parameters such as the ideality factor n and the saturation current temperature exponent m (or xti) are the major terms contributing to the temperaturedependent nonlinearity in existing device models. Extraction of the parameter m, in particular, from measured characteristics of a diode is heavily dependent upon the extraction algorithm used which suggests that there are limitations in the functional form of existing device models when used in applications where the precise relationship between current, voltage, and temperature is critical. A two level classification of unauthentic ICs into counterfeits and Trojan bearing ICs is discussed that separates perpetuators driven by financial incentives for selling commodity components from those driven by a disruptive payload goal. A technique is discussed for practically introducing identifiers into any IC that eliminates financial incentives for the much more prevalent counterfeit IC problem.