Computational Modeling of Quasi-Periodic Rudin-Shapiro Multilayered Band Gap Structure

The optical transmission spectra proprieties of the one-dimensional quasi-periodic multilayered photonic structures according to the Rudin-Shapiro distribution are studied theoretically in this paper by using a theoretical model based on the transfer matrix approach for normal incidence geometry. The influence of the layer number has been studied, i.e. the iteration order of the generating sequence of the quasi-periodic structure on the structure spectral behavior and the width of the Photonic Band Gap (PBG). It was found that the width of the PBG is proportional to the index contrast.

Broadband Koch Fractal Boundary Printed Slot Antenna for ISM Band Applications

A new broadband radiating slot antenna with fractal shape is modeled, fabricated and experimentally studied. The presented slot antenna is examined for first three iterations. Optimization of iteration factor (IF) and iteration angle (IA) have been done for each iteration order (IO) to enhance impedance bandwidth significantly. All the antennas are fed with a simple microstrip line. Bandwidth achieved with Antenna 1 (IO=1, IF=0.35 and IA=600) is 1550 MHz which is five times more than that of the square slot antenna. The performance of the proposed fractal slots is also compared with the rotated slot antenna. The experimental data validates the reported analysis with a close agreement.

The Novelty of Infinite Series for the Complete Elliptic Integral of the First Kind

According to the fact that the low convergence level on the complete elliptic integral of the first kind for the modulus which having values approach to one. In this paper we propose novelty of the complete elliptic integral consists of the new infinite series. We apply the scheme of iteration by substituting the common modulus with own modulus function into the new infinite series. We obtained so many new exact formulas of the complete elliptic integral derived from this method correspond to the number of iteration order. On the other hand, it has been also obtained a lot of new modulus functions rather than common used previously. The calculation results show that the number of significant figures of the new infinite series of the complete elliptic integral of the first kind is increased more and more. It means more fastly convergent would be obtained comparison values with the previous infinite series.

Reactive impedance surface-based broadband circularly polarized Koch fractal boundary microstrip antenna

A circularly polarized (CP) broadband antenna is proposed for wireless applications in the range of 2–3 GHz frequency. It consists of asymmetrical Koch fractal boundary patch over a reactive impedance surface (RIS) substrate. The simulations of single-layer Koch fractal antenna, dual layer with square and fractal RIS elements are carried out in a systematic way for broadband CP radiation and corresponding results are presented. For better CP characteristics, properties of fractal curves and dimensions of RIS elements are optimized. The antenna with fractal RIS iteration order one (iteration1) is experimentally studied. The 10-dB return loss bandwidth is 50.35%, whereas 3-dB axial ratio bandwidth is 7.45%, which indicate that by applying fractals concept to RIS technique, with a single probe feed, broadband CP radiation can be obtained.