In this article, a compact four-port MIMO antenna system resonating from 4.7–5.1 GHz on −6 dB criteria is discussed. The proposed antennas are arranged in a perpendicular manner providing diversity with good isolation characteristics. The proposed antenna was fabricated and designed on a commercially available low-cost FR-4 substrate with a relative permittivity of 4.4. The total size of the antenna is 40 × 40 mm², and a minimum isolation of 25 dB was observed at most nearby resonating elements. The proposed antenna was fabricated and tested at an in-house facility, and the measured results agree well with the simulations. The MIMO antenna characteristics, such as the envelope correlation coefficient (ECC) among any two radiating elements, have been found to be less than 0.1, and the diversity gain (DG) value evaluated showed that the proposed antenna is well designed. Furthermore, the SAR analysis showed that the desired antenna system is safe for users, with a value of 0.94 W/Kg. The channel capacity (cc) was found to be 18.7 bps/Hz, approximately 2.7 times more than SISO systems. Through its robust and reliable performance and its peak gain of 2.8 dBi, the proposed compact antenna is a good candidate for future 5G devices.

In this research, a novel T shape antenna is proposed for millimetre-wave (mmwave) 5G systems. Designed on 0.254mm thin Roggers 5880 substrate with a dielectric constant of 2.3 and the loss tangent of 0.0009, the proposed antenna offers a wideband characteristics of nearly 8GHz with gain of 4.25dBi for single element. Based on these characteristics, the single element is further constructed into a four-element linear array with a compact size of 18.5×24mm² The proposed antenna array exhibited dual beam radiation patterns with a high realized gain of 11.5dBi and 94 efficiency. The measured results from the fabricated prototype well agree with the simulated results and thus, therefore, make the proposed antenna system a well-suited candidate for future mmwave devices.

In this work, a low-cost, deployable, integratable, and easy-to-fabricate multiple-input multiple-output (MIMO) Kirigami antenna is proposed for sub-6 GHz applications. The proposed MIMO antenna is inspired by Kirigami art, which consists of four radiating and parasitic elements. The radiating and parasitic elements are composed of a rectangular stub. These elements are placed in such a way that they can provide polarization diversity. The proposed MIMO antenna is designed and fabricated using a soft printed board material called flexible copper-clad laminate (FCCL). It is observed from the results that the proposed MIMO antenna resonates in the 2.5 GHz frequency band, with a 10 dB reflection coefficient bandwidth of 860 MHz ranging from 2.19 to 3.05 GHz. It is worthwhile to mention that the isolation between adjacent radiating elements is higher than 15 dB. In addition, the peak realized gain of the MIMO antenna is around 11 dBi, and the total efficiency is more than 90% within the band of interest. Moreover, the envelope correlation coefficient (ECC) is noted to be less than 0.003, and the channel capacity is ≥17 bps/Hz. To verify the simulated results, a prototype was fabricated, and excellent agreement between the measured and computed results was observed. By observing the performance attributes of the proposed design, it can be said that there are many applications in which this antenna can be adopted. Because of its low profile, it can be used in 5G small-cell mobile MIMO base stations, autonomous light mobility vehicles, and other applications.

Nowadays, more attention has been given into ultrawideband by dint of its extraordinary features over narrowband communication systems. This study presents a novel compact with tilted square frames shape antenna with partial ground plane. The proposed antenna is printed on commercially available Fr4 substrate with relative thickness of 1.6mm. The antenna has compact dimensions of 14×18mm² with bandwidth ranging from 3.3 to 11.5GHz. The peak gain obtained is 1.4dBi with omnidirectional radiation characteristics throughout the entire bandwidth. The proposed antenna is fabricated, and the developed prototype measured results, which well agree with simulated results. With the performance parameters obtained and the well agreed measured results, the proposed antenna is well suitable for Wi-Fi, ISM, and UWB applications.

In modern communication systems, ultra-wideband (UWB) technology has garnered substantial attention due to its superior attributes compared to traditional narrowband communication systems. Over the past decade, UWB technology has also found applications in microwave-based imaging systems. This study introduces a simple planar coplanar waveguide-fed circular shape arc slot antenna designed specifically for biomedicine and microwave medical imaging applications. The proposed design is implemented on a 1.6-mm-thick FR4 substrate with a relative permittivity of 4.4 and a loss tangent of 0.0009. The antenna has physical dimensions of 26 mm × 29 mm and achieves an impressive bandwidth of 16.6 GHz, spanning 2.4 to 19 GHz. It exhibits a peak gain of 2.5 dBi and consistent omnidirectional radiation characteristics. Thorough temporal analysis validates the antenna's performance within acceptable limits, which is further affirmed through practical fabrication and testing, demonstrating strong agreement with simulation results.

A compact four‐element UWB MIMO antenna system with pattern and polarization diversity is proposed to achieve wide impedance bandwidth and improved multiport performance. The antenna is designed on an FR4 substrate with a thickness of 1.575 mm and a relative permittivity of 4.4, while the overall size of the proposed structure is 48 × 48 mm ² . The developed MIMO configuration covers a wide operating band from 2.5 to 20 GHz, corresponding to a fractional bandwidth of 146%. The mutual coupling between antenna elements is effectively controlled, and the measured isolation is better than 15 dB throughout the operating range. The proposed antenna also provides acceptable radiation characteristics, with efficiency varying from 50% to 84% and a peak gain of 4.8 dBi. The measured results of the fabricated prototype are in good agreement with the simulated data, confirming the validity of the design approach. Moreover, the evaluated MIMO performance parameters, such as envelope correlation coefficient and diversity gain, remain within standard acceptable limits. Compared with recently reported UWB MIMO antennas, the proposed design combines a compact four‐port polarization‐diversity configuration with a loop‐fed clover‐shaped radiator to achieve an ultra‐wide operating bandwidth of 2.9–20 GHz while maintaining stable radiation characteristics, low mutual coupling, and excellent diversity performance. The compact geometry, simple planar structure, and experimentally validated performance make the proposed antenna a promising candidate for next‐generation ultra‐wideband wireless communication and sensing applications.