Satellite communications involve transmission of microwaves.  Such microwaves can have small wavelengths and be transmitted at high frequencies in the gigahertz (GHz) range.  Antennas can produce focused beams of high-frequency microwaves that allow for point-to-point communications having broad bandwidth and high transmission rates.  A measurement that can be used to determine if an antenna is properly functioning is a microwave frequency response.  This is a quantitative measure of the output spectrum of the antenna in response to a stimulus or signal.  It can provide a measure of the magnitude and phase of the output of the antenna as a function of frequency in comparison to the input stimulus or signal.  Determining the microwave frequency response for an antenna is a useful performance measure for the antenna.