An Inflatable Membrane Impulse Radiating Antenna

Ultra-Wideband (UWB) antennas with broad bandwidth and large apertures could be of great use in a variety of space-based applications, including radar, communications, and surveillance. The challenge is to deploy a large lightweight UWB antenna that isstowable in a small volume, and that will be resistant to the harsh space environment. To overcome these challenges we propose an inflatable impulse radiating antenna fabricated from a thin membrane such as mylar or kapton. The proposed design is called aMembrane Impulse Radiating Antenna, or Membrane IRA. The antenna is inflated during deployment, and then the membrane may be hardened by epoxy or coated with a thin layer of foam that becomes rigid. In this manner, the antenna will be hardened againstpuncture by small space-borne particles. The Membrane IRA is a blend of two well-established foundation technologies. The first of these is the Collapsible Impulse Radiating Antenna (CIRA), which has an umbrella-like design and is now a commercial product.The second foundation technology is inflatable large-aperture reflectors fabricated from membranes such as mylar or kapton. The combination of these two technologies will lead to a space-capable deployable large-aperture antenna that is operational overtwo decades of bandwidth. During Phase I we will build and test a scale model of a Membrane IRA, with diameter of around four feet. Testing will include both a mechanical deployment demonstration and a measurement of the antenna pattern. We will alsoinvestigate methods of structurally hardening the membrane after deployment, so puncture becomes less of a problem. Finally, we will investigate replacing cables in the feed design with printed circuit transmission line.This research will lead to a newdesign for an inflatable Membrane Impulse Radiating Antenna. This device will have very broad bandwidth, will be lightweight, and will fit into a small volume on a satellite before deployment. A scale model approximately four feet in diameter will be builtduring Phase I.