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A variable-height dielectric resonator reflectarray for X-band operation has been described in this paper. The unit cell consists of a rectangular dielectric resonator, conducting plane with etched slot printed on a standard FR4 substrate. The array consists of 97 elements arranged in a circular fashion and it is illuminated by a pyramidal horn. The mutual coupling between the feed and the elements is considered for full-wave analysis. Through a waveguide setup having plane wave excitation at one end, the phase variation with change in height of the dielectric resonators and the reflection efficiency for effective re-radiation of the incident plane waves are computed theoretically using CST Microwave Studio Suite employing Finite Integration Technique. From the simulated results, total gain of 23 dB is achieved along with 24 % bandwidth for 1 dB gain variation at 10 GHz making the reflectarray suitable for radar, remote sensing, radio astronomy, digital broadcasting applications, etc. [ABSTRACT FROM AUTHOR]

A low profile dual-band frequency selective surface (FSS) for shielding the GSM applications is presented in this paper. The proposed FSS contains the unit cell made of modified double square loop elements with paper as its substrate. The overall thickness of the proposed FSS measures only 0.55 mm. The FSS offers band stop response at 930 and 1720 MHz with 18 dB shielding effectiveness for a bandwidth of 100 and 173 MHz, respectively, thus shielding the GSM signals. Additionally, the modified double square loop element-based FSS is symmetrical providing the advantage of polarization independency. It also exhibits angular stability up to 60° for both the horizontal polarized electric field (TE mode) and vertically polarized electric field (TM mode). A prototype of the proposed dual-band low profile FSS is fabricated. The simulation results are compared with the experimental results and are found to be in congruence with each other. [ABSTRACT FROM PUBLISHER]

In this article, two-element monopole multiple input-multiple output (MIMO) antenna with polarisation diversity for 4G and other applications has been presented. The designed antenna covers 16% (1701-2001 MHz) of bandwidth around the design frequency (1850 MHz) which includes both DCS-1800 and DCS-1900 bands. The two antennas are placed orthogonally and symmetrically with edge-to-edge spacing of 5.5 mm (λ0/30). With the placement of interconnected swastika-shaped resonator between the two monopole antennas, there is an isolation enhancement of 60 dB thus reducing the envelope correlation coefficient value ranging from 0.016 to 6.12 × 10-10 and improving the diversity gain ranging from 9.9 to 10 dB within the -10 dB bandwidth. A prototype has been fabricated and validated using measurements. [ABSTRACT FROM AUTHOR]

A novel compact folded antenna for 4G and 5G application in handheld devices such as mobile phones is proposed in this paper. The radiator comprises of meandered monopole, dual L-Shaped monopole, square radiator, asymmetric U-Shaped monopole, Closed Loop resonator, F-Shaped stub for providing the desired operating bands. The size reduction is achieved using folding technique. The antenna can be easily folded and integrated at the top right corner within the metal casing of the devices. Folded structure with the foot print of 50 × 6 mm2 covers multiband operation such as LTE700 / GSM850 / 900 / LTE 2300 / WLAN 2400 / LTE 2500 / Wi-MAX 3500 / Wi-Fi 5200/5800 MHz corresponds to 2G/3G/4G/5G services. To provide high data rate and throughput, MIMO concept is exploited with the folded radiators at the top left and right corners of the printed circuit board. The realized gain and radiation efficiency of the proposed antenna are 2.45/4.12/4.54/5.03/6.58 dBi and 82/85/87/89/90% respectively at the design frequencies 0.7/2.3/2.5/3.5/5.8 GHz. The SAR values of the folded antenna is computed and found to be less than 1.6 W/Kg. [ABSTRACT FROM AUTHOR]