A multi-layer S/X-band shared aperture antenna array for airborne synthetic aperture radar applications

摘要

In this work, a dual-band dual-polarized (DBDP) S/X-band multilayer sharedaperture antenna (SAA) for airborne synthetic aperture radar (ASAR) applications.The proposed multilayer SAA DBDP S-band antenna is designed with the conceptof the cross-shaped patch with proximity coupled feeding in both vertical and horizontalpolarizations and X-band antenna design is with aperture coupled squarepatch arranged as a 4×4 planar array for high gain and narrow beamwidth withcorporate 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 andcold regions, and for disaster monitoring. To verify the antenna design concept, aprototype is fabricated and measured with both S-parameters and radiation characteristicsincluding gain measurements. The S/X-DBDP SAA has fractional bandwidthof 7.7% at 2.7 GHz and 4.8% at 9.7 GHz, respectively, and the port isolationbetween 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 SAAis best suited for large size array antenna for ASAR applications.