QUASI-ELLIPTIC FUNCTION FILTERS WITH A DUAL-PASSBAND RESPONSE WITH HIGH-PERMITTIVITY CERAMICS SUBSTRATE

摘要

The miniaturization of dual-passband filters by employing two high-permittivity ceramic substrates (with respective dielectric constants of 4.5 and 20.8) are investigated. Microwave dielectric ceramics with high permittivity are commonly applied in several microwave communication components. With the advantages of compact size, high-permittivity ceramics can be used as the substrate for dual-passband filters. Moreover, the fundamental characteristics of newly developed compact stepped impedance resonator (SIR) have also been described and applied to the design of band-pass filters. In this article, the designed ring resonators structures are simulated using an IE3D simulator. The responses of the fabricated dual-passband filters using FR4 (ε{sub}r = 4.5, Q × f = 350,000 GHz) and 0.96 Mg{sub}(0.95)CoTiO{sub}3-0.04SrTiO{sub}3 with 1 wt% ZnO addition (ε{sub}r = 20.8, Q×f = 74,000 GHz) ceramic substrates are designed at the center frequency of 2.4/5.2 GHz. This compact size, low loss dual-passband filter should be useful in many wireless communication systems.