Insensitivity Characteristics in the Dual Polarization of Deployable CFRP Reflector Antennas for SAR

A large deployable reflector antenna is considered and designed for the application of a synthetic aperture radar system requiring high gain for the high resolution of a detected image within a distance of a few hundred kilometers. For its lightweight and strong characteristics, carbon fiber reinforced polymer (CFRP) is introduced as a composite material and fabricated for conductivity evaluation. Effective electrical characteristics are obtained as a function of carbon fiber direction, using measured S-parameters in a rectangular waveguide. By taking into account the changes of the effective electrical characteristics that depend on the fiber direction of reflector antenna, the radiation pattern is investigated at X-band in terms of gain and polarization variation effects. The proposed reflector antenna made of quasi-isotropic CFRP panel can realize the insensitive characteristics depending on the incident polarization.