SCANNING CHARACTERISTICS OF INFINITE ARRAYS OF PRINTED ANTENNA SUBARRAYS

In this paper the analysis and scanning characteristics of several different types of infinite arrays composed of subarrayed printed dipole and microstrip patch elements are presented. The analysis is based on full-wave moment method theory, and includes mutual coupling between elements in the subarray as well as between subarrays. The effect of subarraying on scan blindness is demonstrated for arrays using two-element subarrays of printed dipoles and microstrip patches, and it is found that subarraying can eliminate or reduce mismatch due to scan blindness. Results are also given for the amount of power radiated in grating lobes, which in many cases is found to be the primary factor that limits the practical scan range of subarrayed arrays. This paper also considers the effect of a subarray composed of one driven element and one parasitic element, and the use of a four-element synchronous subarray of microstrip patches to generate circular polarization. Data are given for impedance mismatch, power radiated into grating lobes, and the axial ratio; both square and rectangular patches are considered, and it is found that rectangular patches give better performance for all characteristics. Finally, results are shown for an infinite array of seven-element hexagonal subarrays of printed dipoles, and it is found that the large spacing between subarrays leads to a limited scan range.