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2026-07-25 Latest Published

A Miniaturized 5.8 GHz WLAN Pentagonal Microstrip Antenna with Fractal DGS and FSS Reflector for Gain Enhancement
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By Nagari Naveen Kumar Dupakuntla Vishnu Vardhan

Progress In Electromagnetics Research C, Vol. 172, 7-17, 2026

doi:10.2528/PIERC26050205 | Google Scholar

Abstract

In this article, a Miniaturized Pentagonal Antenna (MPA) with a Minkowski Curve, Fractal Defected Ground Structure (MCF-DGS) and Frequency Selective Surface (FSS) is proposed for 5.725-5.875 GHz WLAN application. The performance of a λ/4 transmission line-fed pentagonal patch antenna is examined using an iterated MCF-DGS etched on the ground plane. In the beginning, a fundamental antenna (Antenna-1) is designed and measured at 13.2 GHz with a S₁₁ of -32.45 dB. After that, the resonant frequency of the fundamental MPA has been reduced from 13.2 GHz to 5.8 GHz by employing MCF-DGS (Antenna-2) with 56% miniaturization. The S₁₁ of MCF-DGS measured for single-band frequency 5.8 GHz is -33.36 dB. The performance attributes of an MPA with improved efficiency, peak directivity, and peak gain via MCF-DGS and FSS (Antenna-3) are also analysed. The proposed antenna of 15 × 16 mm² (or 0.29λ₀ × 0.30λ₀ mm²) with a height of h₁ = 1.6 mm is designed, produced, and tested on a substrate of FR4 epoxy. The peak gain and peak directivity at 5.8 GHz are elevated from 1.74 to 7.40 dBi and 3.53 to 7.95 dBi by using an FSS composed of FR4, with a thickness of h₂ = 1.6 mm, situated under the MPA at a height of h₃ = 8.5 mm. The prototype model's test results are validated by the predicted outcomes of the proposed model.

2026-07-25

PIER C

Vol. 172, 7-17, 2026

doi:10.2528/PIERC26050205

download: 2

A Miniaturized 5.8 GHz WLAN Pentagonal Microstrip Antenna with Fractal DGS and FSS Reflector for Gain Enhancement

Nagari Naveen Kumar and Dupakuntla Vishnu Vardhan

2026-07-24

PIER C

Vol. 172, 1-6, 2026

doi:10.2528/PIERC26012204

download: 16

Cylindrical Conformal Electrically Small Antenna with Quasi-Isotropic Radiation Pattern for Mine Gob Communication

Qiushou Liu, Kunshan Mo, Jin Wu, Lin Peng and Rui Fang

Wireless communication nodes in the underground mine gob area are often disturbed by different orientations; therefore, antennas with quasi-isotropic radiation are critical for reliable wireless communication. To address this challenge, a compact, cylindrical, conformal, quasi-isotropic antenna operating in the VHF band is proposed. The design integrates a shorted-patch structure with orthogonal dipole radiation, formed by a shorting post and patch aperture, to realize nearly isotropic Radiation. A capacitive-coupling feed is employed to enhance impedance matching, yielding an impedance bandwidth of about 1.02 MHz (S₁₁ < -10 dB) at 170 MHz. The fabricated prototype, with dimensions of 120 mm × 120 mm × 110 mm (0.068λ₀ × 0.068λ₀ × 0.063λ₀), was validated through full-wave simulations and experimental testing. The two results show excellent agreement, demonstrating a measured maximum-minimum gain variation of only 2.74 dB, confirming the antenna's good quasi-isotropic characteristics. Owing to its compact volume, stable matching, and consistent omnidirectional coverage, the proposed antenna is a good candidate for underground mine gob area communication nodes.