New compact microstrip stacked slotted resonators bandpass filter with transmission zeros using high-permittivity ceramics substrate

The miniaturization of hairpin band-pass filters by employing two high-permittivity ceramic substrates (with respective dielectric constants of 9.7 and 26.1) 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 band-pass filters. Moreover, the fundamental characteristics of newly developed slotted resonators. In this article, the designed vertically stacked slotted resonators structures are simulated using an IE3D simulator. The responses of the fabricated filters using Al₂O₃ (ε_r = 9.7, Q × f = 350,000 GHz) and 0.8(Mg _0.95Zn_0.05)TiO_3- 0.2Ca_0.61Nd _0.26TiO₃(ε_r = 26.1, Q × f = 46,000 GHz) ceramic substrates are designed at a center frequency of 2.45 GHz, This vertically stacked slotted resonators and sharp cutoff frequency response band-pass filter should be useful in many wireless communication systems.