Investigating Nonlinearity in Radio Telescope Receivers Using the MeerKAT System

An investigation into nonlinear distortion in the high-sensitivity radio receivers used by the MeerKAT telescope is presented. The trade-off between dynamic range and sensitivity is introduced, and a description of the receiving signal chains is given, indicating how the system analyses signals and where nonlinearities could manifest. An overview of the system engineering test of receiver linearity is discussed, indicating that the nonlinearity presents as an increase in system gain in the presence of strong interfering signals. The investigation includes measurements at the integrated interferometer and individual Digitiser levels in the laboratory.