Apparatus for generating an RF signal for use in RF signal detection is described. The apparatus comprises at least one processor configured to generate a set of IQ data based on at least one set of weighted IQ data, each set of weighted IQ data having a respective weight and a circuit configured to generate an RF signal using the set of IQ data. The at least one processor is configured to calculate each respective weight in dependence upon location of a signal detector or an antenna associated with the RF signal detector.