Microstrip posts and dielectric resonators showing a steep slope at lower and upper stopbands for bandpass properties

In this work, two types of novel microstrip structures providing a steep slope at lower and upper stopbands for bandpass characteristics are proposed. The structures have been formed by means of TEM mode dielectric resonators and capacitive or inductive shunt posts in microstrip line. Equivalent circuits of various combined structures have been formulated. S-parameters of the structures have been obtained from a series of experiments and equivalent circuit calculation, and have been compared with each other. The result has also been compared with the measurement and the equivalent circuit calculation for the inductive block.