Modeling,Design,and Zero Gravity Testing of a Doubly Curved Aperture Antenna

Abstract

A smart aperture antenna whose reflector is deformed by curved piezoelectric actuators is modeled and the results are experimentally verified in a microgravity environment. The reflector is modeled as a shallow spherical shell with a small hole at the apex for mounting. Using Reissner's shallow spherical shell theory, five equations governing the mechanical behavior of the reflector structure are reduced to two equations. These are described in terms of a stress function and the axial deflection. As actuators, four PZT strip actuators are attached along the meridians separated by 90 degrees respectively. The forces developed by the actuators are modeled as distributed pressure loads on the reflector surface. In addition to the analytical model, a finite element model is generated to verify the analytical model on the various surface positions of the reflector. Finally, an actual model of the reflector is built and tested in a zero gravity environment. The experimental data show good agreement with those obtained from the analytical and the finite element models.

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