Novel Parasitic Micro Strip Arrays for Low-Cost Active Phased Array Applications

In this paper, a novel idea is proposed to construct low-cost phased arrays by using the multi-port property of array elements. The operating principles are illustrated and explained in detail. A three-element patch subarray with a periodic lattice is conceived according to the proposed idea. In the subarray, one patch antenna with multiple ports is designed as an active element which is directly fed through the excitation port by a feeding network. The other two parasitic patches are fed by the coupling ports of the active element. Good agreements between simulations and measurements of a two-subarray phased array prototype successfully verify the proposed idea. Then, comparisons to a conventional phased array are performed to highlight its advantages, e.g., high aperture efficiency and low cost. Finally, a second design example is given for more references.