The paper proposes the coaxial-sector antenna-feeder device (AFD), which is given for longitude output of high-power pulse microwave radiation from generator with magnetic isolation. The proposed device is sufficiently compact and allows us to form polar pattern of radiation with the maximum on generator axis. The design description, results of PC modeling and experimental research of coaxial-sector AFD, to be operated as a part of generator with magnetic isolation, which works in range 1.8÷2.1 GHz with power level 1 GWt and length of generation pulse 100 ns, are presented.