Test results of a compact smooth-walled spline-profile horn at 30-38 GHz for radio astronomy application

A compact smooth-walled spline-profile horn covering the 30-38 GHz frequency band (8 mm radioastronomy band) has been optimized, manufactured and tested. A maximum aperture size was limited by the array application. The measured 3 dB-beamwidths are 40deg/37deg/38deg in the H/E/45deg-planes. The measured sidelobe level is less than -30 dB/-23 dB/-25 dB in H/E/45deg-planes and the maximum gain is 13.8 dBi. The measured cross-polarization level is less than -20 dB at the top of the band. The results of the trial observations at the RATAN-600 radio telescope with the horn are given. The antenna measurement and test results are in good agreement with simulation. We consider using such a horn as an efficient feed of a multi-beam receiving array for a radio telescope.