A High-Efficiency, Low-Phase Error Waveguide Lens for a Transform Feed Antenna,
ROME AIR DEVELOPMENT CENTER GRIFFISS AFB NY
Pagination or Media Count:
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 beam ports ands 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 bandwidth. Over the same 8.0 to 10.0 GHz band, total power loss in the lens was less than 2.3 dB including mismatch, spillover and reflectioon losses.