A Low-Sidelobe Space Feed Lens,

Abstract : A parallel-plate waveguide microwave lens, constructed as part of the concept development of completely overlapped subarray antennas, was modified and tested. The lens function is comparable to that of a Rotman lens with 16 inputs (bma ports) and 60 outputs (antenna ports). However, the input face is linear with uniformly spaced monopole elements, and the output face is circular, with monopole elements spaced uniformly in angle. Using a four-way power divider at the center four inputs and the outputs connected to a line-source array, low sidelobe patterns were measured over a 22 percent bandwidth. Over the same 8.0 to 10.0 GHz band, total power loss in the lens was between 0.3 and 1.3 dB including mismatch, spillover and reflection losses.