Single channel radio direction finder - has fast Fourier transform non-recursive digital filtering and goniometer connected to receiver

摘要

The direction finder is single-channel working with a goniometer connected to a receiver. The output signal of the latter is multiplied with a complex carrier whose angular frequency is the same as the angular frequency of rotation of the goniometer. The resulting signals are filtered to remove the sidebands and provide an output signal to drive the display unit. The receiver contains a non-recursive digital filter as the frequency-selective element and which fulfill the filtering function by means of fast Fourier transformation. All signals within the tuning range of the multi-channel receiver are resolved together and the required radio bearings are selected by means of an automatic signal gating unit.