A novel method of tuning the properties of microwave dielectric resonators

Dielectric resonators (DRs) with positive temperature variation of resonant frequency (τf) has been stacked with resonators with negative τf. The stack acted as a single resonator. The τf of the resultant stack depends on the volume fraction of the positive τf and negative τf DR materials. The τf can be tuned to 0 or to a desired value by adjusting the volume fraction of the positive and negative τf materials. The dielectric constant and quality factor also change depending on the volume fraction of the two different DR materials. The experiment is performed with varying volume fractions of Ba5Nb4O15 as the positive τf DR and Sr(Y1/2Nb1/2)O3 and 5ZnO–2Nb2O5 as the negative τf DR materials. The DR material in the bottom of the stack has greater influence on the τf of the resultant stacked resonator.