Development of enhanced ultra wideband antenna designs and rake receivers for indoor wireless systems

Abstract

The ultra-wideband (UWB) technology in the present and future is considered as one of the wide promising wireless technologies. For this reason, there are many indoor short range wireless applications such as mobile devices, laptops, scanners, printers, and flash drives are suitable in use. These devices are going to be miniaturized all over the world to be lightweight for carrying and low cost purposes. This characteristic increases the real demand on designing small size UWB systems. In this thesis, five UWB antenna designs and five UWB rake-receiver structures are proposed to cover the entire UWB frequency range (3.1-10.6 GHz) as defined by Federal Communication Commission (FCC) that consequently provides many challenges in the wireless communication area including antenna design and receiver scheme. These proposed antennas have small sizes and improved gain and radiation efficiency compared with the literature ones and the performances are analyzed under several antenna parameters to guarantee that the transmitted signal will be correctly recovered at the receiver end. The small antenna designs are low profile printed patch with planar ground plane antennas that satisfy UWB technology requirements and they are namely: bird feet-shaped patch antenna, planar finger-shaped patch antenna, rake-shaped patch antenna, slotted and notched rectangular patch antenna, and spade-shaped patch antenna. The designed antennas have compact sizes of 1.575 x 40 x 35 mm3, 1.575 x 30 x 28 mm3, 1.575 x 30 x 30 mm3, 1.575 x 30 x 26 mm3, and 1.575 x 30 x 28 mm3; and cover the following frequency bands 3.1-12 GHz, 3.5-12 GHz, 3-12 GHz, 3.3-14 GHz, and 3.5-12 GHz; respectively. The substrate material used is Taconic TLY-5 to reduce the cost of antenna.