ThisApplicationNotedescribestheoperatingprincipleofDME(DistanceMeasurementEquipment)thatisusedfordistancemeasurementinaviation.ItalsodescribesvarioustestscenariosforthemaintenanceofaDMEtransponder.ThesetestsrequireanR&S®SMA100AsignalgeneratorwithR&S®SMA-K26DMEmodulationoption,and