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

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 dualplane 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 0.071λ
_g
× 0.097λ
_g
× 0.002λ
_g
.