Dual-polarized linear series-fed microstrip arrays with very low losses and cross polarization

The design of a microstrip series-fed linear traveling-wave array is described in this paper. The array is composed of two symmetric subarrays formed by cascading an equal number of four-port aperture-coupled cross-patch elements and terminated on a two-port radiating matched load. Dual-linear and circular polarization can be achieved by appropriately exciting the array and by virtue of the symmetric arrangement of the antenna high polarization purity is obtained. A proof-of-concept linear array is developed and the corresponding numerical results performed through a full-wave approach based on the method of moments are presented.