RF Circuit Analysis of UWB Planar Log Periodic Antenna for 5G Communications Using Theory of Characteristic Modes

Fifth generation (5G) wireless communication systems demand compact and low-profile high gain wideband antenna. Planar log-periodic array antenna (pLPA) has such potential qualities for 5G base-station and user-devices. However, many important features and RF analysis are rarely elaborated for pLPA which include equivalent circuit modeling. In this article, authors present the systematic RF analysis, fabrication, and equivalent circuit modeling for sub-6GHz 5G application using theory of characteristic modes (TCM). The fabricated pLPA is designed to cover the 5G bands with a high gain of >5 dBi and a fractional bandwidth of >1. Using simulation tool based on method of moments, radiating and non-radiating modes are tracked and studied with detailed physics. These modes are modeled using analytically derived equivalent circuit and assembled in an RF/microwave circuit simulator. The characteristic mode analysis and RF circuit modeling of pLPA help in the advancement of future 5G RF front-end modules.