Development of Corona and Multipaction-Free Waveguide Offset-Iris Filter for X-Band TT&C Application in Deep Space Missions

For the new deep space missions, for the first time, X-band has been proposed for the telemetry, tracking and command (TT&C) application. Design of filters at higher frequencies with high power handling capacity and high rejection requirements, but free from the inevitable high-power problems under vacuum conditions viz., corona and multipaction, is challenging as the size and internal dimensions are small. This paper presents development and qualification of waveguide offset-iris filter, designed to operate at the transmitter frequency band (8.42 to 8.54 GHz) with a CW power level of about 10.0W and an insertion loss of better than 0.25 dB. To achieve isolation between high power transmitter & sensitive reviver, filter with a rejection of better than 80.0dB at the receive band (7.0-7.3 GHz) is designed. Furthermore, the high-power test results show that the filter is free from corona and multipaction.