An ultra-compact impulse-radiating antenna

摘要

We describe the development of an ultra-compact impulse-radiating antenna (UCIRA), intended for space applications in low Earth orbit. Because a UWB (ultrawideband) antenna was desired for this application, an IRA (impulse-radiating antenna) was selected as the starting point for this development. The standard IRA configuration has a single linear polarization, and has a very narrow beamwidth at high frequencies. A dual-polarization antenna was desired with a larger beamwidth, so we modified the existing design to support dual polarization, and we used a hyperbolic reflector to increase the beamwidth. The antenna also had to survive the harsh space environment, had to be lightweight and very compact for launch, and had to be remotely deployable. A deployable IRA with dual polarization using a flexible twinline feed has been developed that has very good RF characteristics. Also, the theory for IRAs with hyperbolic reflectors and defocused feeds has been advanced. The UCIRA-2 developed here metmany of the requirements.