A multi‐layer S/X‐band shared aperture antenna array for airborne synthetic aperture radar applications. Issue 8 (24th April 2021) - Kothapudi, Venkata Kishore
Abstract: In this work, a dual‐band dual‐polarized (DBDP) S/X‐band multilayer shared aperture antenna (SAA) for airborne synthetic aperture radar (ASAR) applications. The proposed multilayer SAA DBDP S‐band antenna is designed with the concept of the cross‐shaped patch with proximity coupled feeding in both vertical and horizontal polarizations and X‐band antenna design is with aperture coupled square patch arranged as a 4 × 4 planar array for high gain and narrow beamwidth with corporate feeding for good radiation characteristics as array design. The S‐band (2.7 GHz) is best suited for soil moisture; X‐band (9.7 GHz): mainly for snow and cold regions, and for disaster monitoring. To verify the antenna design concept, a prototype is fabricated and measured with both S‐parameters and radiation characteristics including gain measurements. The S/X‐DBDP SAA has fractional bandwidth of 7.7% at 2.7 GHz and 4.8% at 9.7 GHz, respectively, and the port isolation between S‐ and X‐bands is higher than 25 dB. The design exhibits an SLL ( S ‐band: −13 dB and X ‐band: −15 dB), high gain ( S ‐band: 8.48 dBi and X ‐band: 21.8 dBi). The overall size of the S/X‐DBDP multilayer SAA is 125 × 125 × 8 mm 3 . The SAA is best suited for large size array antenna for ASAR applications.