Low‐cost intelligent antenna with low profile and broad bandwidth

Abstract

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.

Assessment of the adaptive routing performance of a Wireless Sensor Network using smart antennas

“…Standard WSN devices with monopole antenna usually exhibit a very poor performance in multipath scenarios [8], and this can severely limit their operation. In contrast to monopoles, smart antennas [9][10][11][12] are able to dynamically control their radiation pattern as a function of direction. They can steer their main beam towards a desired signal while forming a null in the direction of an interference signal.…”

“…Also they are able to improve the network performance by enabling concurrent transmission in media access control (MAC) and routing layers. Studies of the use of pattern-steering smart antennas in WSNs [12][13][14][15][16] have demonstrated that they can provide benefits in increasing the wireless channel capacity while improving the communication quality. This has the potential to solve many of the challenges faced in WSN development.…”

Small-Size Eight-Band Frequency Reconfigurable Antenna Loading a MEMS Switch for Mobile Handset Applications

“…For further size reduction, these traditional wideband methods with single working state are limited. Considering the limited space for antenna design for mobile handsets, reconfigurable technology [8][9][10][11][12][13][14][15][16][17] is a good candidate. By using the reconfigurable technology, the antenna can work in several states to obtain wide bandwidth with a reduced size.…”

“…By using the reconfigurable technology, the antenna can work in several states to obtain wide bandwidth with a reduced size. Commonly, the reconfigurability is achieved by RF MEMS switches [8][9][10][11], PIN diodes [11][12][13][14][15], and varactors [16,17].…”

“…Reconfigurable antennas loading PIN diodes referred in [13][14][15] have significantly reduced the sizes of the multiband antennas, and they have also been proved with acceptable insertion losses. However, the PIN diode usually acts as a resistance, while larger dc power is required to gain lower insertion loss in practical applications.…”