Low-cost intelligent antenna with low profile and broad bandwidth

In this study, a low-cost intelligent antenna, which has a low profile, high gain and broad bandwidth, is presented. The proposed antenna is an extension of the conventional electronically steerable parasitic array radiator antenna. It consists of one short monopole and 12-folded monopoles. The short monopole is placed in the centre and serves as the driven element and the 12-folded monopoles serve as parasitic elements. The coupling between the driven and parasitic elements provides capacitive loading to the driven element, leading to a low-profile antenna. The use of 12 PIN diodes enables beamforming to be performed using a transistor-transistor logic supply. The front-to-back-ratio (FBR) is improved by introducing a reconfigurable choke ring surrounding the antenna. To validate the concept, a prototype at S band is developed. Both measured and simulated results are presented. The antenna has a height of only 24 mm (0.16 λ at 2.0 GHz) and a broadband bandwidth from 2.0 to 2.5 GHz. Finally, the antenna is employed in a wireless communication system in a multi-path environment and large noise environment. It is shown that the antenna can boost the throughput of a wireless system significantly in both environments.