Implementation and Design of Spherical High-Gain Antennas

Abstract

Rapid advances in telecommunications are occurring for both space-based and ground-based antenna systems. Space-based advances in communications include the rise in using constellations of inexpensive smallsats to form global telecommunications networks. Ground-based advances in telecommunications are seen with the adoption of portable ground stations that can be used to establish satellite communication links at any location on Earth. The advent of these new technologies require new antenna designs to be implemented. One such implementation is the electronically steerable inflatable spherical reflector (ISR) concept. The ISR utilizes a half-metalized Mylar balloon for the reflector and a line feed that incorporates multiple antenna elements with phase and amplitude control to correct for spherical aberration and perform electronic beamsteering. The Mylar reflector can be easily stowed inside a small container prior to ground or space deployment, and the line feed’s electronic beamsteering allows a continuous communications link to be maintained without requiring mechanical means to point the antenna. These characteristics make the electronically steerable ISR concept a suitable candidate for inexpensive, high gain antennas in many applications in space and on the ground. Our primary focus will be on the simulations, analyses, and optimizations of spherical reflectors utilizing various line feed designs for specific RF requirements. We will juxtapose experimental data with the simulation results to compare and validate the performance of each antenna design.