Inflatable impulse radiating antenna for lunar penetrating radar

In this paper, an inflatable impulse radiating antenna (inf-IRA) that can be used in lunar penetrating radar application is described. The inf-IRA is covered by thin films as a main material so that it can be inflated as the air is injected and be packaged small size as the air is deflated. The reflector of inf-IRA, whose diameter and focal length are 0.3 m and 0.15 m, respectively, is made of reflective Mylar film. The parabolic curve is formed by joining planar discs. The structure is supported by attaching internal stays. Two feed arms are printed on a thin Kapton substrate. The arms are designed with an asymptotic conical dipole profile for low input impedance. The reflection coefficients and gain patterns of fabricated inf-IRA are measured and compared to those of simulation and rigid-IRA.