A technical note on HF, VHF & UHF RF coaxial linefilters for EMI suppression (spurious and harmonics)

Multi radio set configuration in vehicles very often generate undesired mutual EMI (both inter modulation and cross modulation products) frequencies at considerable amplitude. When radio sets are not designed to meet those stringent EMI specifications, retrofits, of RF coaxial filters are the only solution, to reject IM/CM products into victim receiver(s). Three different RF coaxial filters chosen for a specific application are evaluated and described in this paper. Test results achieved in laboratory w.r.t supplier´s specification are reported.