Dual-Plane Quadruplexer Using Common Lumped-Element Quadruple-Mode Resonator

Abstract

This letter presents a 0.43 GHz/0.9 GHz/1.575 GHz/ 2.45 GHz quadruplexer with ripple bandwidth of 40 MHz/ 70 MHz/60 MHz/100 MHz using a common lumped-element quadruple-mode resonator (LE-QMR). One resonant mode from LE-QMR and two resonant modes from two $LC$ resonators constitute every channel of the proposed quadruplexer. The dual-plane structure configuration is employed in this design to relieve the limited physical space. A step-to-step design procedure is given to validate our design approach. The measured result shows that the fabricated quadruplexer exhibits low insertion loss, up to 40-dB port-to-port isolation and compact size of $0.071\lambda _{g}\times 0.097\lambda _{g}\times 0.002\lambda _{g}$ .