Characteristic Parameters of an Antenna

Summary

Certain parameters need defining precisely in order for readers to properly understand how they are used. Such is the case of the capture surface, which does not only apply to aperture antennas. In a link budget, we use the formula to find the noise power available at the reception access of an antenna. Indeed, it is when the antenna is in receiver mode that the noise generated by different sources becomes important in determining the quality factor, particularly in applications relating to satellites. This chapter presents the case of a single‐carrier satellite downlink because of the availability of a simple equation for the link budget, given by the Friis equation. The quality factor of a link is defined by the antenna's receiver gain and its system temperature at the receiver access point.