Bandpass filter using dielectric resonator with transmission zeros

This article presented a design of the planner bandpass filter using a combination of a microstrip line, dielectric resonator (DR). The proposed bandpass filter was constructed by mounting dielectric resonator on the surface of printed circuit board. DR had permittivity 93.5 feed by a microstrip line to excite the EM field and introduced transmission zeros in the lower cutoff frequency. Three C shape slots were introduced in the ground plane to generated transmission zeros at the upper cutoff frequency. Coupling between the DR was increased by using three parallel transmission lines. By exploiting transmission zeros and coupling between DR a two pole dielectric resonator bandpass filter resonating at 2.18 GHz with 193 MHz bandwidth was designed, fabricated, and measured. The experimental results of two pole dielectric resonator bandpass filter was in good agreement with the designed and simulated response. Designed filter exhibited improved spurious performance in MIC environment. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1583–1586, 2016