High performance reflector hat antenna with very low sidelobes for radio-link applications

Reflector antennas with self supported waveguide feeds of swan-neck type are often used in radio link systems. If there are requirements for very low sidelobes, it is common to attach an absorbing cylinder to the rim of the reflector. Both the cylinder and the feed are expensive to manufacture. The paper describes a so called hat antenna which is cheap to manufacture, compact, light-weight and in addition has very low sidelobe performance. An experimental model with 43 cm reflector diameter has been built and measured at 15 and 30 GHz.