5G COMMUNICATION

The study examines the firm specific determinants of the performance of insurance firms in Nigeria over the period 2019 – 2023, using descriptive statistics, correlation analysis and panel least squares regression techniques. A causal research design was adopted for the study. The firm specific factors considered in this study include firm size, capital adequacy, leverage, liquidity and firm age while insurance firm performance was proxy by return on asset. It adopts a multivariate panel least squares analysis for the estimation process. The finding of the study reveals that firm size, liquidity and firm age has a positive and insignificant effect on performance of insurance companies while capital adequacy and leverage has a negative and insignificant influence on performance of insurance firms. The study recommends among others that management of insurance firms should focus less on growing the size of insurance firms in Nigeria. Also, regulatory authorities should ensure that insurance firms comply strictly with capital adequacy set by the regulatory authorities.

The rapid expansion of fifth-generation (5G) wireless networks demands antenna arrays with wide bandwidth, high gain, and efficient beamforming capabilities to facilitate ultra-high-definition video streaming, extensive Internet of Things (IoT) connectivity, and communications with minimal latency. Nevertheless, traditional microstrip patch antennas continue to face fundamental challenges, including limited bandwidth, strong mutual coupling in array configurations, and reduced radiation efficiency caused by dielectric and surface wave losses. These challenges hinder their suitability for high-performance 5G applications. This project presents the design and simulation of a 4 × 4 microstrip patch antenna array optimized for sub-6 GHz 5G applications. The Rogers 4350B substrate is utilized because of its low-loss characteristics and stable dielectric properties. To improve performance, U-shaped slots are added to the radiating elements, and a Defected Ground Structure (DGS) is incorporated into the ground plane. The design, analysis, and optimization of the antenna are carried out using ANSYS HFSS, focusing on achieving wide impedance bandwidth, high gain, and improved inter-element isolation without physical fabrication. The selection of materials, substrate parameters, and design dimensions are carefully chosen to facilitate future fabrication and experimental validation. Simulation results show that the proposed antenna achieves a gain of 10.64 dB, a bandwidth of 180 MHz, radiation efficiency of 72.3%, and a return loss (S11) of –19.96 dB at 3.5 GHz. In comparison, the conventional 4 × 4 array of the same dimensions without slots and DGS recorded a gain of 10.31 dB, no substantial bandwidth as the return loss
at the resonance frequency, 3.5 GHz, is above the -10 dB line, efficiency of 64.39%. The observed improvements are primarily attributed to the DGS, which effectively suppresses surface waves, minimizes mutual coupling, and enhances current distribution uniformity, across the array. Overall, the optimized DGS-based antenna demonstrates superior performance in terms of gain, bandwidth, and element isolation, making it a strong candidate for compact and efficient sub-6 GHz 5G base station and user terminal applications. The findings of this study provide a useful framework for further research and practical realization of high-performance antenna arrays for next-generation wireless communication systems.