A two‐element super‐wideband (SWB) MIMO antenna is proposed in this study. A step impedance microstrip feed line structure is introduced to achieve an SWB impedance bandwidth of 185%. This antenna is designed to be circularly polarised at 1.575 GHz (L ₁ ‐band) and 26.0 GHz (K‐band) by using closed ring resonator on the radiating patch. The EBG structures are used to improve FBR in lower (1.5–5 GHz) and higher bands (25–35 GHz). The proposed antenna is designed with compact size 55.6 × 50.5 × 1.6 mm ³ on FR‐4 substrate including exotic diversity performance. This MIMO antenna is suitable for defence and handheld devices covering GPS/DCS/PCS/UMTS/Wi‐BRO/ISM/IRNSS/LTE (M/HB)/BLUETOOTH/IoT/WiMAX/X/Ku/K/Ka‐band and it is also suitable for 5G (sub‐6 GHz/mm) applications with channel capacity of 11.34 bps/Hz. Simulated results of MIMO antenna like radiated power‐based ECC and diversity parameters are also verified experimentally, which are in the acceptable range. Finally, this antenna is tested in a realistic environment for SAR application.

In this paper, small printed urn-shape triple notch ultra-wideband (UWB) monopole antenna with diverse wireless applications is presented. Notch bands include WiMAX (IEEE802.16 3.30–3.80GHz), WLAN IEEE802.11a/h/j/n (5.15–5.35GHz, 5.25–5.35GHz, 5.47–5.725GHz, 5.725–5.825GHz), and X-band downlink satellite system (7.25–7.75GHz) and other multiple wireless services as close range radar (8–12GHz) in X-band & satellite communication (12–18GHz) in Ku-band. By including T-shape stub and etching two C-shaped slots on the radiating patch, triple band-notch function is obtained with measured high band rejection (VSWR=16.54 at 3.60GHz, VSWR=22.35 at 5.64GHz and VSWR=6.38 at 7.64GHz) and covers a wide useable fractional bandwidth of 154.56% (2.49–19.41GHz). In short the antenna offers triple band-notch UWB systems as a compact multifunctional antenna to reduce the number of antennas installed in wireless devices for accessing multiple wireless networks with wide radiation pattern

In this article, a UWB metasurface absorber is designed for a frequency range of 6.75GHz-14.5GHz. The absorber consists of a simple unit cell size of 0.265λ ₀ ×0.265λ ₀ ×0.103λ ₀ on a single-layer FR-4 substrate with a thickness of 3.1mm. It has greater than 90.0% absorbance. Next, an X-band circularly polarized MIMO antenna is developed on an FR-4 substrate with a thickness of 1.0mm. The antenna has dimensions of 0.966λ ₀ ×0.766λ ₀ ×0.053λ ₀ . The MIMO antenna’s S-parameters, radiating efficiency, gain, and diversity parameters are further indicators of its usefulness. The designed metasurface is also employed as a tool to enhance the peak gain of the proposed MIMO antenna up to 8.8dBi and reduce radar cross-section by 18dBm ² , by placing the metasurface array superstrate and down correspondingly. The simulated and measured results for the metasurface and antenna, both individually and collectively, are more harmonious, demonstrating the applicability of the suggested designs for IoT over satellite, military applications, and identifying blood clots in CT-scan applications.