Dual-band Beam Waveguide Fed Terahertz Antenna for Ground Telescope

This paper presents the design of 3 m Cassegrain antenna fed by a dual-band beam waveguide. Antenna has been designed to achieve 60 % aperture efficiency and 90% beam efficiency at 0.225 THz and 0.338 THz bands. Gaussian beam parameters like, beam waist and radius of curvature are computed for fundamental Gaussian beam mode at input and output of mirror equivalent lenses for initial design of multireflector antenna. The simulation results of the beam waveguide antenna are presented for various electrical parameters such as beam-width, cross-polar level, side lobe level and efficiency. The realization, assembly and alignment challenges at terahertz frequencies are also discussed. This antenna has been designed for ground telescope to reveal the properties of molecular clouds in the Milky Way Galaxy for astronomical observations.