In this study, a novel dual‐layer wide‐angle metamaterial absorber with polarisation independence has been presented at three distinct frequencies. The proposed structure consists of dual stacked metal‐dielectric layers which are terminated by the metal ground panel. The unit cell of the presented structure consists of three concentric 8‐point star rings on the top surface of both dielectric layers exhibiting three absorption peaks of 98.96%, 98.7% and 99.43% under normal incidence at 1.8 GHz, 2.14 GHz and 2.57 GHz, respectively. The polarisation independence of the design has been validated by numerical simulation and practically verified using waveguide measurement technique. The structure displays high absorption of about 84% for transverse electric polarisation and over 97% under transverse magnetic polarisation up to 60° of oblique incidence. Furthermore, the effects of variation in physical design parameters on absorption response are investigated. The measurement exhibits good agreement with the simulated outcome. The presented structure has a thickness of 0.0294 λ ₀ with respect to the lower absorption band frequency.

In this paper, the design, simulation and measurement of a dual-band polarizationinsensitive metamaterial inspired microwave absorber are presented. The unit cell is composed of two concentric closed ring resonator (CRR) structures forming octagonal rings which are carved on an FR-4 dielectric substrate to give maximum absorption at dual frequencies of 2.09 GHz and 2.54 GHz. At these frequencies, the minimum reflection coefficients of-29.15 dB and-18.76 dB are achieved with absorption rates of 99.88% and 98.67% and narrow 10 dB bandwidths of 2.62% and 2.76%, respectively. Microwave absorption property of the proposed absorber structure is simulated by setting the perfect electric boundary conditions in four planes whose surface normal vectors are directed perpendicular to the wave propagation direction. These numerical computation settings replicate the rectangular waveguide to be used in the experimental measurements for the comparison between the simulated and experimental results. It is experimentally verified by the waveguide measurement method that the absorption rates about 99% are achieved for dual bands with polarization insensitivity thereby meeting the absorption requirements of LTE-band frequencies for a real time microwave absorber based energy harvesting systems.

In this proposal, an advanced integrated multiple‐input multiple‐output (MIMO) antenna system has been presented for next generation 5G‐NR, high speed WLAN and X‐band communications. The four radiators having comb‐shaped geometry at the top edge are positioned orthogonally with each other. An adequate gap is maintained between the radiating ports of MIMO antenna to lower down the mutual coupling. A small fractal geometry is engineered at the bottom corners of the patch to receive size miniaturization, wide band performance and manufacturing advantage. In similar fashion, thin slots are introduced to excel the isolation. The ultrawide band response (1.6 GHz–11.35 GHz) could be achieved by introducing partial ground plane underneath each radiator. A commercially available Flame Retardant 4 substrate was utilized. The individual ground structures are interconnected using thin conducting strips, which play a dynamic role in system performance by providing high isolation between the MIMO elements. The proposed MIMO system is analyzed and confirmed based on various antenna responses such as diversity gain (DG) (>9 dB), mean effective gain (MEG) (−6 to −8 dB), channel capacity loss (CCL) (< 0.4 bits/s/Hz), and envelop correlation coefficient (ECC) (< 0.002 abs). The received reflection coefficient values from the MIMO antenna are compared with actual values. Both the responses are closely aligned with each other. This research supports SDG 9, SDG 11, and SDG 7 by advancing innovative wireless communication infrastructure, enabling sustainable and resilient smart city connectivity, and indirectly promoting energy‐efficient network operations through high‐isolation and efficient antenna design.

In this article design, fabrication and analysis of a compact ultrathin polarization independent wideband metamaterial absorber at microwave frequency is presented. The unit cell of the proposed design constitute of a metallic 12-point star with center cavity and dual half slot at 45° imprinted on top of the grounded FR4 dielectric substrate. The numerical result exhibits full width at half maximum (FWHM) bandwidth of about 16.3% from 1.92 GHz to 2.26 GHz with absorption of above 80%. The absorption mechanism of the presented absorber has been analyzed through parametric variations, electric field distributions and surface current distributions. In addition, absorption of about 70% is achieved at wide angle of incidence up to 45°. The polarization independence is verified via waveguide method by setting distinct orientation angles for the unit cells. Measured results are in agreement with the simulated results. The designed absorber is compact and ultrathin with unit cell size and thickness of less than 0.25λ₀and λ₀/45 at center frequency of absorption.