A novel technique for tuning dielectric resonators

This paper presents a novel technique for the tuning of high dielectric resonators at microwave and millimeter wave frequencies. The resonator is tuned by coupling it to a section of non-resonant microstrip line. An experimental band-reject filter with a Q of 550 was tuned using this technique. The resulting tuning range of the filter was over 18 times its bandwidth. This technique makes it cost effective to tune dielectric resonators over a relatively broad range while maintaining a high Q characteristic