Scanning properties of microstrip leaky-wave phased arrays

An investigation on the radiation features of phased arrays of microstrip leaky-wave line sources is presented. A two-dimensional analysis is first performed, in which the complex wavenumbers and current configurations of the operating leaky modes are determined by means of a spectral-domain moment-method approach in a periodic environment. Rigorous three-dimensional simulations of the actual truncated array are then performed, and the effectiveness of the two-dimensional leaky-wave model for a simple but accurate description of the radiation features of the array is illustrated. Information is provided on shape modifications of the radiated beam occurring over the angular scanning in both elevation and azimuth achieved by varying frequency and phase shift between elements, both in the absence and in the presence of grating lobes.