Design and development of coaxial cavity band pass filters for INMARSAT terminal

This paper describes the design, development and performance of coaxial cavity band pass filters for transmit and receive chains of Standard-C terminal of International Maritime Satellite (INMARSAT) system.The band pass filters are at centre frequencies 1537.5 & 1636 MHz with bandwidths of 15 & 20 MHz with respect to centre.The sharp cut off has been achieved at 1626 & 1545 MHz for receive and transmit band pass filters. The fabrication technique is simple and the filters have better repeatability. The plated Achrylonitrile Butadien Styrene (ABS) plastic-body filters also have been reported in this paper.