A W-Band Circular Box-Horn Antenna Array Radiating Sum and Difference Beams With Suppressed Sidelobe.

A circular aperture box-horn array antenna operating in W-band, with sum and difference radiation beams, is presented in this paper. The circular aperture provides maximum usage efficiency of the area, which is well suited for a rotational platform. Nonuniform power distribution is applied for the radiating elements, contributing to a radiation pattern with suppressed sidelobe. In order to fit into the circular aperture, the feed networks are optimally arranged on a compact two-planar layer with four quadrants fed by the sum–difference network. The antenna array, along with its full-corporate feed networks, has a low profile and is easy to be machined. Measured results show that the peak gain is over 35.6 dBi from 92 to 94 GHz, with up to −21 dBi sidelobe level. In addition, the sum–difference contradictions are less than 4 dB, and the nulls of difference beams are below −25 dB. [ABSTRACT FROM AUTHOR]