Abstract-A superstrate layer is used to enhance the directivity of the small radiation sources such as Microstrip Patch Antennas. In this paper, we use square loop frequency selective surface (SL-FSS) configuration to design the superstrate layer. To compact the structure, we propose a new single layer square loop FSS configuration that operates in two frequency bands such as multi-layer SL-FSS. Simulation results are shown to have good agreement with experimental results.

Abstract-In this paper, the potential use of split ring resonators (SRRs) to design very compact dual-band bandstop waveguide filters is proposed. Two square SRRs are placed on the same transverse plane realizing two independent reject bands. By adjusting the SRRs lengths, the stopbands can be targeted at the desired frequencies. In addition, a simple circuit model for this resonator is introduced. Good agreement between the experimental and full-wave simulated results has been achieved.

Abstract-This paper presents the simulation and fabrication of a new power divider/combiner based on a new waveguide H-plane folded magic-T structure. Measurements of the fabricated magic-T confirm the accuracy of the optimization algorithms existing in the CST software (Genetic algorithm, Particle Swarm Optimization algorithm PSO etc.). The magic-T structure exhibits moderate bandwidth response in the frequency range of 8-10 GHz. Also, it shows that the return loss is better than −15 dB, the insertion loss about −3.4 dB, and the isolation between the two output ports better than −25 dB in the frequency range of 8.4-10 GHz, with good transmission phase characteristics. Based on this magic-T structure, a 1 : 4 power divider/combiner is simulated and tested. The measured results show that the insertion loss is about −6.5 ± 0.25 dB, the return loss less than −15 dB, the isolation among the output ports less than −25 dB, the combining efficiency about 89%, and the transmission phase differences are about ±2 • in the frequency range of 8-10 GHz.