Analysis and design of doubly curved piezoelectric strip-actuated aperture antennas

Abstract

Recently, aperture antennas that have the ability to change their reflector shape through the use of piezoelectric actuators have been studied. The results show that those antennas can exhibit beam steering and beam shaping in the far field. However, many of the previous studies have been confined to cylindrical shape antennas. This study examines the use of "doubly curved" antenna structures to achieve better performance in controlling an antenna's coverage area. The spherical antenna is modeled as a shallow spherical shell with a small hole at the apex for mounting. Following Reissner's approach, a stress function is introduced and two governing equations are derived in terms of the stress function and the axial deflection. Next, the surface deflections are evaluated from the calculated stress function and the axial deflection. As actuators, four lead-zirconate-titanate (PZT) thunder actuators are attached along the meridians separated by 90 , respectively. The forces developed by the actuators are expanded in a Fourier series and fed into the governing equations as boundary conditions at the outer edge. Finally, the deflection versus applied voltage is calculated analytically and its effect on the far-field radiation is given.Index Terms-Aperture antennas, mechanically adaptive antennas.

Optimal steering of a paraboloid antenna using piezoelectric actuators

“…The antenna considered here is made of Lexan® (Young's modulus = 2.3 × 10 9 N m −2 ) as taken by Yoon et al [7] in their study. The thickness of the antenna is assumed to be 0.2 mm.…”

“…One of the applications currently being explored is shape control of antennas. It has been demonstrated that piezoelectric actuators can deform the antenna shell to obtain beam steering and shaping [5][6][7]. Washington [5] and Yoon and Washington [6] proposed the use of PVDF film and PZT strips respectively for shaping and steering of cylindrical antennas.…”

“…Washington [5] and Yoon and Washington [6] proposed the use of PVDF film and PZT strips respectively for shaping and steering of cylindrical antennas. Recently, Yoon et al [7] used piezoelectric actuators to control a spherical (doubly curved) antenna's coverage area. They applied Reisner's shell theory to obtain deformations of the reflector surface analytically.…”