Antenna systems for Czechoslovak-made radio relay links

The paper discusses some of the main problems in setting up the antenna system for a radio relay link, giving primary attention to parabolic antennas, but also giving some information on periscopic antennas. The principal parameters of parabolic antennas used in Czechoslovak radio links are tabularized. These antennas range in size from 1 to 3 m, in frequency from 6.5 to 11.1 GHz, in gain from 37 to 45 dB, and employ chiefly horn radiators. Mutual coupling between antennas is suppressed through the use of a metal collar placed around the circumference of the reflector. The effect of such a collar on the radiation pattern is examined. Some typical measurements of mutual coupling between 3-m parabolic antennas are presented, showing the effect of distance between antennas, horizontal polarization, obstacles, cross polarization, and vertical polarization. Some technical requirements regarding protection from the environment, absorbing material around the collar, and laminated or metal mirrors for the antenna are mentioned. The gain characteristics of some periscopic antennas with various radiator-reflector configurations are discussed.