Agile Antenna for Troposcatter Communications
Abstract
Troposcatter communications has been a topic of interest for the Navy for the past decade. InA2AD environments where SATCOM cannot be relied on, alternative BLOS communications arenecessary. One method is utilizing Troposcatter. PMW/A-170 has had interest in this topic from20161 . In this SBIR, the Navy was interested in utilizing existing shipboard CommercialBroadband Satellite Program (CBSP) C-Band terminals to engage troposcatter.One of the difficulties in Maritime Troposcatter is maintaining beam pointing to the commonscattering volume while the maritime vessel is experiencing pitch and roll. Therefore, an agileantenna which can adjust the beam position rapidly is of great importance. This white paperdescribes a feed reflector system that operates notionally in the X-Band, and has the ability to scanthe beam rapidly without physically moving the feed reflector. This is done through the use of adielectric Risley prism at the feedhorn. The antenna system also utilizes monopulse tracking inorder to keep the beam pointed to the common scattering volume. This is realized through the useof multiple radiating modes.Troposcatter communication systems that operate in the C-Band typically require 100 Watt classpower amplifiers. For this reason, feed reflector antennas are preferred as waveguides can handlehigh output powers. Electronically steered arrays cant generate the high EIRP required andtherefore not an option for agile beam steering. Technologies such as Cubic GATR utilizes aninflatable dish within a sphere, which can be rotated to move the beam. The antenna requiresphysical rotation to point and track. Monopulse offers a high data rate solution in deniedenvironments.This proposal aims to develop an X-Band feed reflector system, which has the capability to scanthe beam in Azimuth plane while maintaining the capability to do monopulse tracking withoutphysically moving the antenna. The antenna will support >1 GHz of bandwidth. The three areasof innovation are:1). Multi-mode feed horn to produce monopulse patterns2). Dielectric Risley prism to enable beam scanning3). Cylindrical reflector to enhance the gain
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 15, 2021
- Source ID
- N000142112134
Entities
People
- Satish K. Sharma
Organizations
- Office of Naval Research
- Salk Institute for Biological Studies
- United States Navy