摘要 |
<p>An antenna feed horn (10) for a satellite antenna array that includes multiple chokes (34, 36, 40, 42, 44) that provide effective control of the horn aperture mode content to generate radiation patterns which substantially have equal E-plane and H-plane beamwidths, low cross-polarization, low axial ratio, and suppressed sidelobes. The chokes (34, 36, 40, 42, 44) are annular notches that have both radial and axial dimensions. Two chokes (34, 36) are provided at an internal transition location between a conical profile section (14) and a cylindrical aperture section (16). Additionally, another choke (44) is provided in the aperture (20) of the horn (10), and two additional chokes (40, 42) are provided proximate the aperture (20). The size and location of the chokes (34, 36, 40, 42, 44) are optimized for the desirable mode content at the frequency band of interest to allow the propagation modes to be properly phase oriented relative to each other so that the useful bandwidth of the signal is on the order of 10% or greater.</p> |