Development of Multilayer Partially Reflective Surfaces for Highly Directive Cavity Antennas: A Study This paper proposes a novel triplelayer partially reflecting surface (PRS) for designing a highly directive antenna. The proposed PRS design has 54% improvement in impedance bandwidth with existing design. The design has multiple cavities, optimized for improved gain and bandwidth performance. The PRS arrays are printed on the dielectric substrate, placed above the ground plane at a height of approximately half wavelength. The reference square microstrip patch antenna operating at a frequency of 5.8xe2x80x89GHz with a gain of 3.77xe2x80x89dBi is enhanced to 13.54xe2x80x89dBi. The measured S11 of the fabricated prototype is xe2x88x9222.12xe2x80x89dB with a VSWR of 1.17xe2x80x89:xe2x80x891. Measured 3xe2x80x89dB gain bandwidth of the antenna is 390xe2x80x89MHz which is an improvement of 50% compared with the reference antenna. This highly directive antenna is suitable for WiMAX wireless application.

Design of QuadPort MIMODiversity Antenna with TripleBand Elimination Characteristics for SuperWideband Applications A compact, lowprofile, coplanar waveguide (CPW)fed quadport multipleinputxe2x80x93multipleoutput (MIMO)diversity antenna with triple bandnotched (WiMAX, WLAN, and Xband) characteristics is proposed for superwideband (SWB) applications. The proposed design contains four similar truncatedxe2x80x93semiellipticalxe2x80x93selfcomplementary (TSESC) radiating patches, which are excited through tapered CPW feed lines. A complementary slot matching the radiating patch is introduced in the ground plane of the truncated semielliptical antenna element to obtain SWB. The designed MIMOdiversity antenna displays a bandwidth ratio of 31:1 and impedance bandwidth (S11 xe2x89xa4 xe2x88x92 10 dB) of 1.3xe2x80x9340 GHz. In addition, a complementary splitring resonator (CSRR) is implanted in the resonating patch to eliminate WLAN (5.5 GHz) and Xband (8.5 GHz) signals from SWB. Further, an Lshaped slit is used to remove WiMAX (3.5 GHz) band interferences. The MIMO antenna prototype is fabricated, and a good agreement is achieved between the simulated and experimental outcomes.