A broadband antenna array for sea scatter measurements

A nonuniformly spaced array of 25 side-terminated vertical half rhombics is synthesized for the entire high-frequency band. The array is to be used for both transmitting and receiving, as a sky-wave Doppler radar for sea scatter measurements. The array has the capability for providing a maximum transmitting-receiving product gain in the order of 60 dB at low take-off angles, a product azimuth pattern with a nominal beamwidth of
2\deg
, a
40\deg
sectoral coverage, a final product sidelobe level of -38 dB, and a grating-lobe level of -30 dB.