Low Cross-Polarization, High-Isolation Microstrip Patch Antenna Array for Multi-Mission Applications

The design and development of a high-performance, dual-polarization, hybrid aperture-coupled microstrip patch antenna are presented. In the presented design, the horizontal and vertical polarizations are excited using the aperture coupling method. The isolation level of better than 51 dB and cross-polarization level of less than -30 dB are achieved from the measurement results of the designed single element. To achieve better cross-polarization levels, the 2 x 2 element subarrays of the proposed unit cell, while the horizontal polarization ports are mirrored, are designed and fabricated, and a lower than -39-dB cross-polarization level is achieved in the measurement results. Finally, to characterize the scan performance of the unit cell and subarray, a 4 x 10 element array of the proposed single element is fabricated and a better than -45-dB cross-polarization level is observed while scanning up to 45 degrees.