Vertical HF and UHF radiation system with superimposed aerials - has isolators for each supply cable to superimposed aerials, disposed in excitation zone of HF aerial

摘要

The aerial system has e.g. superposed HF and UHF aerials, operating in the respective ranges 2-24 NHz and 1030-1090 MHz. A lower HF aerial and an isolator are located in each supply cable (4a,4b) of the upper UHF aerials. The isolators is disposed in that part of the cables located in the excitation zone at the HF aerial. Each isolator comprises two series resonant inductor-capacitor circuit, (L1C1,L2C2) connected in parallel and also connected together on each side by a respective parallel resonant inductor-capacitor circuit (L3C3,L4C4). The reactance arms of the parallel resonant circuits are a quarter wavelength long. The series resonant circuits are open circuit line section.