Hybrid Dielectric TE/TM Mode Resonator Filter with Wide Spurious Free Range and Transmission Zeros Generated by Higher Order Modes

This paper presents a hybrid fourth order dielectric bandpass filter. By combining TE and TM mode ceramics, their individual advantages in terms of high Q-factor and spurious mode performance are exploited. The fundamental modes of the ceramics are used, the T $E_{01\delta}$ and TM 010 mode. In order to couple the different resonator types with each other, they have to be arranged in a proper orientation. The filter has three transmission zeros (TZs), one of which is generated by using a triplet configuration. The other two transmission zeros are generated by higher order modes (HOMs) and can be placed independently from the first TZ and without shifting the passband. Finally the filter has been measured and results are compared with the simulation results.