A Performance Comparison of Sub-Octave Band Corrugated Horns to a Quadruple-Ridged Flared Horn for the ngVLA Radio Telescope

The radiation performance of quadruple-ridged flared horns (QRFHs) has in recent years improved greatly due to the more detailed geometries, such as the addition of corrugation rings in the aperture plane (enhanced performance at the lower part of the frequency band) and the addition of dielectric material in the throat of the horn (for improved upper-frequency performance). Over a narrower frequency band, the QRFH can achieve performance levels that are similar to those of the sub-octave band corrugated horns. This is shown in this paper for the lowest (3:1) frequency band of the ngVLA radio telescope.