A 5-element Shared Aperture Antenna Array for X/Ku-band Airborne synthetic aperture radar (AIR-SAR) applications is presented in this research work. As far as the authors are aware, few shared aperture antennas (SAA) exist that cover both X/Ku-band frequencies. The presented research is focused on designing a dual-band single linear-polarized (DBSP) series-fed center-fed (SFCF) X/Ku-band. The implementation of SAA is with the perception of an SFCF 5element group as one group with three patches that are arranged orthogonal to each other to form two sets (3-patches) to realize a series fed array with coaxial probe feeding method in X/Kubands. The X-band (9.3 GHz) is best suited for soil moisture estimation in agricultural areas; the Ku-band (13.265 GHz): is mainly for snow and cold regions and disaster monitoring. The SAA prototype is fabricated and measured with S-parameters and radiation pattern characteristics to verify the antenna design concept, including gain measurements. The antenna exhibits -10 dB impedance bandwidth (BW) (9.1919-9.4674 GHz) (276 MHz with 2.96% BW) in X-band and (13.054-13.513 GHz) (459 MHz with 3.46% BW) in Ku-band. More than 25 dB of isolation has been measured between the ports and two separate bands in the same polarization. The antenna's X-band gain is 12 dBi at port-1 and its Ku-band gain is 11.3 dBi at port-2, according to the measurements. X-band side-lobe level (SLL) is better than -16.2 dB at port-1 and Ku-band SLL is better than -14.1 dB at port-2, as measured by SLL. The X/Ku-DBSP SAA has total dimensions of 120 × 60 × 1.6 mm 3 and for the presented design, measured and simulated results are in good agreement.