Dual-Polarised Mode Generator for Cross-Polar Ccmpensation in Offset Parabolic Reflector Antennas

Abstract

It has been recently shown that the depolarisatlon and beam-squinting effects exhibited by offset parabolic reflector antennas can be suppressed by means of techmiques based upon focal-plane field matching and the use of higher-order waveguide modes.

Removal of Beam Squinting Effects in a Circularly Polarized Offset Parabolic Reflector Antenna Using a Matched Feed

“…As reported in [12], for the optimum performance of the trimode horn, the TM 11 mode amplitude level should be approximately −5 dB and TE 21 mode amplitude level should be −20 dB relative to the fundamental TE 11 mode. The total power of all the modes at the horn aperture should be 1 watt.…”

A Tri-mode Horn Feed for Gravitationally Balanced Back-to-Back Reflector Antennas

“…A number of techniques can be applied to improve the bandwidth of the feeds. For example, a dual-mode corrugated horn device, employing the HE 11 and HE 21 hybrid modes, has been described in [7] which offers improved bandwidth potential. …”

Tri-mode horn array fed multiple-beam offset reflector antenna with low cross-polarization and improved side lobes

“…Generally, the TM11 mode level should be approximately -5 dB and TE 2l mode level should be -20 dB relative to the fundamental TEll mode. Also there should be in-phase relationship between TEll and TM ll mode and quadrature phase relationship between TEll and TE 2l mode [10]. To study the overall cross-polar performance of an offset reflector, the contour plots were generated.…”

“…For the applications where small focal length (F/D <1) is preferred due to space constraints, a tri-mode hom fed offset reflector is the most suitable option [9][10]. In the present paper, the use oftri-mode hom{s) as primary feed for multiple beam generation is discussed…”