Abstract-Computation of the broadband matching potential of a microstrip antenna requires the wideband lumped equivalent circuit of the antenna. The general topology of the equivalent circuit of rectangular microstrip patch antennas has been used to model the feedpoint impedance of microstrip antennas over a wide frequency band and equivalent circuit parameters are determined using optimization techniques. The proposed procedure overcomes the problems of physical realizability of the equivalent circuit and estimation of the starting values of the optimization. Applying this technique, wideband lumped equivalent circuits of a rectangular and E-shaped microstrip antenna have been computed which are in good agreement with measurement data from 0.1 to 6 GHz.
In this paper an injection-locked optical orthogonal frequency-division multiplexing (ILO-OFDM) method is presented using an optically injection-locked laser. In an ILO-OFDM system, an optically injected semiconductor laser operating in stable locking is utilized to directly modulate the OFDM signal on the optical carrier intensity. To design this system, we first compute the optimal operating condition for the directly modulated injection-locked laser by numerically solving the rate equations. The goal is to achieve the maximum enhanced modulation bandwidth with desirable flatness and simultaneously reduce signal distortions due to the effects of laser nonlinearity. These properties of the injection-locked laser suggest an appealing solution for high-data-rate transmission using OFDM. Next, we design the ILO-OFDM system by directly modulating the RF OFDM signal on the injection-locked laser with the enhanced features. The performance of the proposed method is assessed by numerical simulations, and the advantages of this method over existing optical OFDM systems are explained.Ayaz Ghorbani received a PG diploma, M.Phil, and Ph.D. degrees in the area of electrical and communication engineering from the University of Bradford, UK, in 1984UK, in , 1985UK, in , and 1987. He received a postdoctorate degree from the University of Bradford, Bradford, UK, in 2004.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.