An inflatable deployable polarization agile microstrip antenna for space-borne synthetic aperture radar systems

This paper is concerned with the development of a dual polarized microstrip array for synthetic aperture radar (SAR) applications. The antenna has been conceived to be embedded into large deployable structures exploiting inflatable technology. The array is organized into linear subarrays designed for radiation in the broadside direction. Each subarray is further subdivided into two subarrays which are formed by cascading an equal number of four-port aperture coupled cross patch elements and terminated on a two-port radiating matched load. By properly exciting the array, any kind of polarization of the radiated field can be accomplished. A proof-of-concept subarray is developed and the corresponding numerical results, obtained through a full-wave approach based on the method of moments (MoM), are provided. The symmetric arrangement of the antenna and associated anti-phase feeding technique prevent the main beam from scanning with frequency and is proved to yield high cross-polarization suppression, which is especially valuable for SAR polarimetry.