Reconfigurable beam steering parasitic patch antenna with embedded PIN diode

Abstract

The work described in this dissertation focuses on the reconfigurable beam steering antenna functionality for point-to-multipoint wireless communication application. This concept helps to reduce the antenna size, cost, and gives more flexibility for a customer premises equipment (CPE) to be operated in several modes. The studies involve the microstrip patch antenna of low profile, low cost, ease of fabrication and easy to be integrated with other RF components. Beam steering/forming antenna is useful in the rapid growth of the wireless communication system such as Wireless Interoperability Microwave Access (WiMAX) and Long Term Evolution (LTE). This dissertation introduces the preliminary investigation on a single element reconfigurable patch antenna which uses PIN diodes as the switching mechanism. With that, reconfigurable pattern of an antenna is studied in depth. Then, the dissertation more focused on spiral reconfigurabe beam antenna with aperture coupled feed technique designed on two Taconic substrate with similar dielectric constant of 2.2. It is discovered that such parasitic and mutual coupling technique is able to steer the radiating beam to four different angles of +176°, +10°, -1° and -12°. Therefore, this dissertation continues on designing another steerable beam antenna that uses similar technique of parasitic array and mutual coupling method. (Parasitic element is the element that undirectly excited by the RF induced current. While mutual coupling exists due to the interaction between the adjacent element). The mutual coupling effect has been introduced by the Yagi-Uda antenna in realizing the beam directional ability. Adopting the Yagi-Uda principle, this dissertation has proposeda novel five-element patch antenna (single-fed driven element and four parasitic elements) in achieving the beam steering at ϕ of 0°, 45°, 135°, 225° and 315°. Two reconfigurable antenna prototypes are implemented with embedded RF switching technique with two different types of RF PIN diodes, namely; BAR-5002V and HPND-4005. The first prototype integrates the BAR-5002V on the second substrate layer known as stacked FPPA. While, the second design integrates the HPND-4005 on the similar radiating layer denotes as single layer FPPA. The FPPA is developed by a driven element encircled by four parasitic elements. The driven element is induced by the coaxial feed technique. Each of the parasitic element is positioned in such a way that optimum coupling effect is produced from the arrangement of the driven element and the specified shorting pin locations. Both prototype have achieved an approximate high gain of 8 dBi at all desired phi directions. Measured and simulated results with a very good agreement are obtained, thus the proposed concepts considered valid.