Design and Analysis of Multi Port UWB Antennas for Wireless Applications

Abstract

High-speed wireless internet connection has become an essential requirement of our life which interconnects gadgets like computers, mobile phones, watches, vehicles, homes, hospitals, and many more to the outside world. For the past few years, several researchers and industrialists have been working on improving various tools of wireless communication systems. An antenna is typically considered the most critical component of the wireless system. Since Federal Communication Commission (FCC) in 2002 specified an unlicensed frequency band, i.e. 3.1-10.6 GHz, research and development activities in UWB antenna technology have been highly encouraged. The main aim of the proposed thesis is to design and analyse new multi-port low-powered ultra-wideband (UWB) antennas for wireless applications. Especially our goal is to maintain the inter-element isolation, which can poorly degrade the whole communication system. Several methods have been exploited in this work to reduce the mutual coupling among radiators at the design level. Furthermore, the number of radiating elements in an electronic device constantly escalates while the area remains limited, so the mutual coupling increases and isolation enhancement becomes more challenging. Moreover, some interfering high-power wireless narrow bands, such as Wi-MAX, WLAN, C-band, X-band etc., have been a critical concern in attaining the desired characteristics of the UWB-MIMO antennas. This thesis comprises some novel compact planar multi-port UWB antenna designs. All the simulations of the proposed work have been carried out in CST-MWS software, whereas VNA and anechoic chamber is considered for measurement purposes. The work of the thesis has been completed in multiple stages, which are illustrated as follows. Initially, a novel compact dual-element UWB-MIMO radiator is developed, which employs the concept of a shared radiator, where two different micro-strip feed lines are used for its excitation. Another dual-element quasi-self complementary (QSC) MIMO antenna is designed