Surface Mountable L- And C-Band Pre-distorted Filters for Frequency Converters of High Throughput Satellite systems

In this paper the design and first experimental results of surface mountable bandpass filters in the L- and C- bands are presented. Used for frequency converters in High Throughput Satellite (HTS) systems, the L-band filter is centred at 960MHz with 500MHz bandwidth (FBW=52%) while the C- band filter is centred at 5.35GHz with 2.5GHz bandwidth (FBW=47%). The results presented in this paper are the outcomes of an ESA ARTES AT project called SUMO ('Surface Mountable Filters for Frequency Converters'). Pre-distorted filter characteristics are proposed for both L- and C-band architectures in order to obtain flatter in-band responses (IL- flatness<1dB). Concerning the L-band filter, two solutions are proposed and compared by combining commercial SMD lumped components with customized LTCC elements. About the C-Band filter, a distributed solution based on edge-coupled quarter- wavelength resonators is proposed. Before the fabrication of the final engineering models, multiple prototypes have been designed in order to test the LTCC fabrication process and materials used for LTCC architectures. The results of these preliminary analyses are shown in this paper.