Compact Tri-Band Bandpass and Bandstop Filters Based on Hilbert-Fork Resonators

摘要

In this work, a multi-mode Hilbert-fork resonator consisting of two dual-mode resonators is presented. The behavior of the proposed configuration is analyzed in detail. To demonstrate the potential of the proposed resonator, tri-band bandpass and bandstop filters operating at 2.4/3.5/5.2 GHz have been designed, fabricated and measured. Both filters are characterized by good performances and very compact size of only $0.21 lambda_{g}times 0.11lambda_{g}$ and $0.22 lambda_{g} times 0.1lambda_{g}$ , respectively.