Miniature monolithic microwave frequency diplexers

Two novel diplexers composed of active, lumped, and transversal element filters that have been developed as monolithic microwave ICs (MMICs) are described. One diplexer produces a low-pass cutoff band edge at 7.5 GHz and a high-pass turn-on band edge at 9 GHz, while the second diplexer produces two passbands, one from 12.5-13.5 GHz and the other from 15.5-16.5 GHz. These are the first reported active MMIC diplexers. Both diplexers have 30 dB of signal rejection 1.5 GHz from their band edges. The use of active transversal filters produces the high rejection characteristic and yields compact diplexers that can be used as building blocks in miniature microwave-frequency multiplexing applications.<
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