A Novel C/X-Band Linear Polarized Conformal Shared Aperture Antenna Array for Spaceborne SAR Applications

In this work, a dual-band linear polarized C/X conformal shared aperture antenna (SAA) for spaceborne SAR applications is presented. The proposed single layer SAA is designed with a square-shaped patch in linear polarization and arranged as four elements ( $2\times 2$ ) array with corporate feeding to allow for efficient signal transmission. The design of that operates at C-band (5.35 GHz) and X-band (9.65 GHz). Most spaceborne applications, such satellite radar and weather forecasting, employ the C-band antenna. On the other hand, X-band antennas are used for surveillance, reconnaissance, air traffic control, and weather monitoring. A prototype is built, and its s-parameters are tested to confirm the antenna. With the suggested design, we were able to obtain a bandwidth of 65 MHz for C-band and 354 MHz for X-band, as well as gains of 13.2 dBi for the C-band and 10.6 dBi for the X-band, and isolation of more than 40 dB. The total size of the SAA size is $130\times 80\times0.8$ mm. According to this study, dual band antennas operating future SAR spacecraft on a same aperture is a practical solution to satisfy user demands.