A compact high‐gain rectangular dielectric resonator antenna (RDRA) using metamaterial (MTM) as superstrate for C‐band applications is proposed in this article. The proposed antenna consists of coaxial‐fed RDRA with 50 unit cells of MTM arranged in 5 × 10 layout as superstrate. Each unit cell is constructed of two parallel eight‐shaped copper strips printed over both faces of a dielectric substrate to provide negative refractive index from 7.3 to 8.1 GHz covering the maximum bandwidth of RDRA. The extracted lumped equivalent circuit model of unit cell of MTM shows concurrence with electromagnetic simulations. The use of MTM superstrate increases the peak gain of the antenna by 89% through simulation and 86% experimentally. The measured results show that the proposed antenna achieves an impedance bandwidth of 16.1% over a band of 7.18‐8.44 GHz, with a peak gain of 14 dBi at 7.8 GHz.

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A novel cylindrical dielectric resonator antenna based on Fibonacci series approach is presented in this letter. Because of the presence of major and minor axis, the antenna characteristics resemble an Elliptical DRA. Optimized radius to height ratio (a/h) of the antenna and probe feed at an offset position (x = 10 mm, y = 1 mm) from the center is responsible to excite the orthogonal modes and generate quadrature phase shift in polarization of wave, that is, achieving circular polarization. Impedance bandwidth (|S11| < −10 dB) and 3‐dB axial ratio bandwidth achieved are 106.5% (6.1‐12.6 GHz) and 18.9% (10.6‐12.6 GHz), respectively. Fundamental HE11δ and HE12δ modes are excited at 9.1 and 10.8 GHz resonant frequency respectively and maximum gain attained is 7.6 dBi at 8.7 GHz. Peak radiation efficiency of 90% at 7.2 GHz is attained by the proposed dielectric resonator antennas. This antenna supports C, X, and Ku band applications like satellite communication, amateur radio (10‐10.5 GHz), weather monitoring and so on. Simulated and experimental results are in close agreement for fabricated proposed structure.

In this paper, a full-wave analytical theory has been proposed based on the field theory approach and numerically solved for computing radiation properties of the dielectric-loaded helical antenna (DLHA). First, the dispersion equation is analytically derived from the source-free Maxwell equation subject to necessary boundary conditions. Then radiation characteristics of DLHA are derived using the field theory approach. The effect of polarization current arising due to dielectric on radiation properties is addressed for the first time in the case of DLHA. All the numerical analysis is carried out in MATLAB. To further validate the results, computation analysis is carried out using CST Microwave Studio Software. From the result, it was observed that when the circumference of the antenna (C) is comparable to the wavelength (λ) corresponding to operating frequency then the wave propagates axially through the helical wire in the axial direction and is radiated in the end-fire direction whereas when the circumference is not equal to the wavelength then the wave gets radiated in the normal direction and attenuated in the axial direction. Also, the impedance bandwidth of the antenna is increased from 2.5% to 52.9% and the gain is increased from 8.35 dB to 11.5 dB due to teflon loading. Finally, the antenna prototype is fabricated, measured, and compared with the numerical and computational results. A close agreement between the analytical, computational, and measurement results are found.