Bandwidth improvement of inlined coupled rectangular waveguide band pass iris filter for space borne missions

Abstract

Over the past decades, filter technology has evolved due to advancement in RF technologies demanded by defense and scientific research systems i.e. Ground based radars, Air borne and Space borne applications. Microwave waveguide filters are one of the critical components in full duplex RF satellite systems that have acquired much importance among satellite communication filters. For air borne and space borne applications, it is used as a receiver protector technology at the output of Jammers in Radars, at the front end of sensitive channelized receiver. Using resonator technology, Iris filter provides narrow pass bands with outstanding selectivity and high stop band rejection. Therefore, Equiripple waveguide filters have become essential option to remove inter-symbol noise and to shape spectrum in space borne communication. In this paper, procedures for synthesis, optimization techniques to improve bandwidth of 5th order Chebyshev band pass iris filter are proposed. Filter is designed to resonate in a frequency range of 8.2 to 8.35 GHz. This single mode cavity filter is a part of pre-selector required to limit bandwidth for transmitter/receiver in a communication satellite/ Radars. Coupling matrix technique along with half wave topology is implemented to carry out results. Design is optimized using HFSS (Eigen and Driven modal) to achieve desired coupling bandwidths good reflection coefficient and narrow bandwidth.