Microwave Holographic Tuning of a Dual-Polarized Ku-Band Microstrip Antenna Array

This paper presents the design, measurement and diagnosis of a panel of a spaceborn, dual-polarized Ku-band microstrip antenna array for future SAR imaging of terrestrial snow covering. A novel hybrid feeding scheme is proposed to achieve dual polarizations, and the design is believed to be unique by applying a single-layered substrate while maintaining the compact size. The microwave holographic imaging technique is applied to obtain actual amplitude and phase distributions as a guideline for fine-tuning the array configuration, in order to compensate the mutual coupling effect induced by closely-placed transmission lines. Both 1x16 and 4x16 subarrays are prototyped and measured, with desired radiation patterns achieved after array diagnosis using holographic images achieved in near-field measurements.