Planar Shared-Aperture Phased Array Antenna Based on Radiation Structure Reuse

In this letter, a planar S-/C-band shared-aperture phased array antenna (SAPAA) based on radiation structures reuse is proposed. Compared with conventional SAPAAs using two different radiators, the proposed SAPAA is based on only the higher-band array elements but reuses the radiation structures in the lower band. Therefore, the long-standing problems that conventional SAPAAs suffer from, e.g., shading effects and dual-band deteriorating interference, are fundamentally solved. Calculated results show that the proposed SAPAA can scan up to ±60° in both the E- and H-planes, with active VSWRs below 2.5 within 4.9 GHz to 6 GHz. Meanwhile, the proposed array can scan up to ±60° in the E-plane and ±30° in the H-plane, with active VSWRs below 3 within 2.7 GHz to 3 GHz. Finally, an array prototype is fabricated, and a good agreement is achieved between the measured and calculated results.