Antenna measurements in space with Spacelab

In satellite communications the ground station antenna, usually a large parabolic reflector antenna with or without a subreflector, has to meet stringent requirements. This applies also for antennas on board of the communication satellite e.g., the ATS F and the Intelsat IV satellites which are provided with large parabolic reflectors. Although the entire directive gain pattern is subject to these requirements, the problem may be divided into two main parts, the main beam with the near-angle sidelobes and the far-angle sidelobes. Radiation properties of the antennas, wire properties and temperature and frequency bonds are discussed.