This paper presents high isolation 4-port 'Ice-cream Scoop' shape ultra-wideband (UWB) multiple input multiple output (MIMO) antenna. It consists of 4 radiating elements with defective ground structure at the bottom side of the antenna. The stub is inserted into the ground plane in between two elements of the antenna, resulting in a maximum isolation S₁₂ of -35.61 dB. The antenna is fabricated on FR4 substrate material with the thickness of 1.6 mm.  The proposed antenna has dimensions of 46 mm x 48 mm. The proposed antenna achieves the wide impedance bandwidth of 3.8 GHz to 11 GHz. The maximum gain value achieved by antenna is of 5.24 dBi. The diversity gain of the antenna is 10 dB, while the ECC value is <0.001 and the CCL is 0.008 bits/sec/Hertz. In all, results depicts that this antenna exhibits good MIMO antenna characteristics. It covers the n46 (5.15 GHz – 5.925 GHz), n47 (5.855 GHz – 5.925 GHz) and n79 (4.4 GHz – 5 GHz) bands of Sub-6 GHz band. To summarize, this antenna proves to be low profile, cost effective simple structure with high isolation.

This study proposes a design methodology for a compact triple-band wireless power transfer (TB-WPT) system for near-field applications. The proposed system employs two identical interleaved resonators coupled in a back-to-back configuration and operates at 180 MHz, 420 MHz, and 780 MHz. Compared with a conventional defected ground structure (DGS) design, the interleaved resonator provides nearly a 30% size reduction without performance degradation. Moreover, the proposed topology integrates three resonant paths into a compact interleaved structure, enabling triple-band operation with reduced footprint and preserved modal independence. Separate transmitter TX and receiver RX structures are implemented, each with a footprint of 30 × 40 mm², and power transfer is achieved via electromagnetic (EM) resonant coupling between the TX and RX resonators. At a 20 mm transmission distance, the TB-WPT system introduced in this work achieves maximum efficiencies of 95% at 180 MHz, 76% at 420 MHz, and 71% at 780 MHz. The measured data are compared with relevant prior work. The proposed system provides a favorable balance among compact size, triple-band operation, transfer distance, and measured efficiency. 

This paper presents a dual-core photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) biosensor for refractive index (RI) sensing. Unlike many previously reported PCF SPR biosensors that focus primarily on plasmonic material optimization or require complex fabrication procedures involving metal deposition inside air holes, the proposed design systematically investigates the influence of air-hole geometry on sensor performance using a simple externally gold coated dual-core PCF structure. Two PCF topologies with distinct air-hole configurations are comparatively analyzed to evaluate the effect of geometric parameters on sensing characteristics. The proposed sensor is numerically investigated using the finite element method (FEM), and key performance parameters, including confinement loss, wavelength sensitivity, wavelength resolution, and RI detection range, are evaluated. The results demonstrate that air-hole geometry has a significant impact on sensing performance. The optimized structure achieves a maximum wavelength sensitivity of 17,000 nm/RIU and a refractive-index resolution of 7.69×10?6 RIU within the RI range of 1.33–1.40. Operating in the near infrared region, the proposed biosensor combines high sensitivity, excellent resolution, structural simplicity, and fabrication feasibility, making it a promising platform for biochemical,  environmental, and biochemical sensing applications.