Summary
Characteristics of a low-sidelobe phased array antenna are investigated using the technique of planar near-field scanning. The theory associated with the planar near-field scanning technique, with and without probe compensation, is reviewed and an application of the theory is made. The design of an experimental low-sidelobe phased array antenna consisting of monopole elements which are corporate-fed using high precision transmit/receive modules is described. Accurate array radiation patterns are obtained both theoretically and experimentally using centerline scanning at less than one wavelength distance from the antenna. The effects of the antenna probe on the array near-field pattern, plane-wave spectrum, and far-field pattern are demonstrated theoretically using a method of moments numerical simulation. Comparisons of the array theoretical near-zone electric field and array received voltage due to a V-dipole near-field transmitting probe are made. It is shown that a V-dipole theoretical probe antenna can accurately model a practical near-field measurement probe consisting of an open-ended rectangular waveguide surrounded with anechoic material.