Manifestations and limits of dual-mode filter configurations for communications satellite multiplexers

It is noted that dual-mode filters and multiplexers now figure prominently in designs for satellite input and output multiplexing networks. In selecting a multiplexer, however, the designer is handicapped in that comprehensive design and trade-off information is not available for this type of structure. All possible manifestations of the dual-mode configuration from fourth to twelfth order filters, including dual-mode allpass networks, are described. Attention is given to the available response functions with equiripple passband, to the possible mechanical configurations to realize them, and to their relative sensitivities. Owing to the severe constraints on the transmission channel characteristics of future satellites, a number of the new response functions and design configurations described here are likely to form the baseline design of future multiplexers.