A Low Cross-Polarization Smooth-Walled Horn With Improved Bandwidth

摘要

Corrugated feed horns offer excellent beam symmetry, main beam efficiency, and cross-polar response over wide bandwidths, but can be challenging to fabricate. An easier-to-manufacture smooth-walled feed is explored that approximates these properties over a finite bandwidth. The design, optimization and measurement of a monotonically-profiled, smooth-walled scalar feedhorn with a diffraction-limited $sim 14^{circ}$ FWHM beam is presented. The feed was demonstrated to have low cross polarization ($u0003C;-$30 dB) across the frequency range 33–45 GHz (30% fractional bandwidth). A power reflection below $-$ 28 dB was measured across the band.