Tri-Band and Quad-Band Filter Design Using E-Shaped Resonators

Abstract

The semi-analytic procedure is provided for triband and quad-band filter design based on E-shaped resonators. With analytic synthesized procedure in dual-band filter design and connect two filters using double-diplexing configuration, the tri-band and quad-band performances can be achieved. The simulated results for the synthesized filters agree well with the ideal performances after some fine tuning. Two microstrip implementations are provided to demonstrate the reliability of tri-band and quad-band filter design.