Transmission Line Circuit Model Research Articles

SAW Convolver Utilizing Sezawa Wave in a Monolithic ZnO/Si Configuration

The optimum design for the monolithic Sezawa wave ZnO/Si convolvers is clarified on crystal cuts and SAW propagation directions in silicon. Theoretical analysis was carried out using an equivalent transmission line circuit model of SAW. The calculated bilinear convolution characteristics well agree with the experimental results. The terminal convolution efficiency FT=-47.5 dBm was obtained in the [001] direction on (110) Si. Dynamic range over 80 dB was observed in the [011] direction on (100) Si. The temperature and dc gate bias stability characteristics are described.

A Nonlinear Circuit Model for Transmission Lines in Corona

A phenomenological transmission line corona model is proposed in this paper which accommodates the diverse aspects of steady-state and transient power and energy losses and change in capacitance. Single phase line sections have been represented by a nonlinear model circuit which changes its state depending on the present and the previous values of the voltage. Propagation with corona is simulated by cascading identical model circuits and the nonlinear transmission line equations are solved by a finite difference method. The charge-potential characteristics of line sections and the nonlinear propagation characteristics of voltage surges computed numerically from our model conform with available experimental data in the literature.

A Nonlinear Circuit Model for Transmission Lines in Corona

A Nonlinear Circuit Model for Transmission Lines in Corona

Transient Nonlinear Circuit Models of Scattering Antennas with Corona

This study investigates the effects of air breakdown on the transient response of a monopole antenna excited by an incident step-function plane wave. A simple transmission-line circuit model of the antenna is developed and the response of this model is shown to agree very well with a finite-difference solution of the problem. This model correctly predicts the time when air breakdown occurs, the general shape of the antenna response, and the amplitude of the response to within a factor of two. The main effect of the air breakdown on the antenna response is to inject a sharp spike in the antenna base current waveform.

Exact equivalent circuit model for steady-state characterization of semiconductor devices with multiple-energy-level recombination centers

One-dimensional steady-state characteristics of a two-terminal semiconductor device is modeled by an exact transmission-line circuit model, This is generalized to include Shockley-Read-Hall (SRH) recombination centers with an arbitrary number of energy levels. It is then applied to a study of the double-acceptor zinc centers in silicon p-n junction diodes. The exact internal characteristics of the diodes; such as the spatial variation of carrier densities, electric field, net charge density, recombination rate, and current densities; are obtained numerically from the circuit model and studied at different injection levels. The zinc population and the relative importance of recombination at each of the two zinc energy levels is interpreted by the Sah-Shockley theory for multiple-energy-level SRH centers.

Free charge propagation in a resistive-gate MOS transmission line

A detailed computer analysis of the charge-transport process in an MOS transmission line (MOSTL)operating in deep depletion is presented. The mathematical model is developed taking into account time-dependent gate voltages, field-dependent surface mobility, and voltage-dependent depletion capacitance. A distributed transmission line circuit model similar to that obtained in a previous work for charge-transfer devices is derived. The charge-propagation characteristics are discussed and interpreted. The contributions of the physical transport mechanisms are investigated from the standpoint of assessing the influence of the design parameters and operating conditions on the performances of the structure. Several driving techniques which use time-varying gate voltages are proposed and simulated. Special emphasis is directed toward the possible improvements in the performances of an MOSTL used as a bit line in a continuously charge-coupled RAM or as a variable delay line for digital signals. Under some simplifying assumptions, an approximate model which yields closed-form solutions for the operational parameters of interest that compare well with the numerical calculations is developed. To a certain extent, the theory derived in this paper is also valid for charge-transfer devices, in particular for the charge-transfer process in bucket-brigade devices and under the transfer gates of two-phase CCD's.

Application of the equivalent circuit model for semiconductors to the study of Au-doped p-n junctions under forward bias

The Green-Shewchun method of solution is applied to the transmission line circuit model of Sah to obtain the forward current-, capacitance-, and conductance-voltage characteristics of semiconductor p-n junctions. Numerical solutions are obtained for diffused dopant impurity profiles and several position dependent concentration profiles of gold recombination centers to illustrate the variation of the reciprocal slope parameter m in the dc current, exp (qV/mkT). A new behavior of m = 2 is observed for many decades of current in the low-level range when the recombination centers are concentrated at the edge of the space-charge layer as expected from ion implantation. The theoretical calculations are compared with experimental forward current-, conductance-, and capacitance-voltage data from 10 to 106Hz and 77 to 300 K. Excellent agreements are obtained without adjustable parameters for boron and gold diffused p+-n silicon diodes from low to high injection levels. A twenty-five fold increase of the steady-state hole lifetime from low to high injection level is both observed and predicted. Agreements are also obtained for phosphorus- and gold-diffused n+-p silicon diodes from low to intermediate injection levels where the steady-state electron lifetime is nearly constant and controlled by electron capture into the positively charged gold donor centers.