A Novel Stacked Ceramic-Monoblock Filter With Highly Flexible Transmission Zero Pair

In this letter, a novel five-pole monoblock dielectricresonator (MDR) bandpass filter with two transmission zeroes (TZs) based on the compact stacked configuration is proposed. The TZ pair is introduced with great flexibility and can be readily allocated at either or both sides of the passband with only a few filter dimension adjustments. The proposed filter has a simple fabrication process with tuning flexibility since there is no need to weld or assemble cavities. A 2.6-GHz filter with a symmetric TZ pair and 150-MHz bandwidth is fabricated. Measurement results show good agreement with simulated responses for validating the design theory.