Methods and means of measuring the gain and ellipticity coefficient of spacecraft antennas

One of the main components of any spacecraft is antennas, which are used to receive and transmit information. An inherent stage of spacecraft production is ground experimental testing (GET) of both the complete spacecraft and its individual parts, including antennas. After the antenna has passed the another stage of testing, it is necessary to verify that its radio technical characteristics (RTC) comply with the requirements stated in the technical specification (specifications). The most important characteristics of any antenna are its gain and ellipticity coefficient (EC). The purpose of this article is considering the main methods of measuring the gain and EC of microwave antennas. In the article such well- known methods of measuring the gain and ellipticity coefficient as three- antenna method, comparison method, flat screen method are considered. The three- antenna method on a planar near- field scanner, with using two paths, and using an indicator receiver are considered. The method of comparison on a collimator antenna range is described, in two variants: using two reference antennas, with one of which the signal amplitudes are measured, and using a two- channel power meter.