A Tunable Waveguide Filter Designed with a Constantan Absolute Bandwidth U sing a Single Tuning Element

This paper presents a novel configuration for a high Q tunable waveguide filter with a constant absolute bandwidth that requires the use of only a single tuning element. The tunable waveguide filter is capable to achieve a tuning range of over 15% with a very minimum bandwidth variation. A 15 GHz waveguide filter with a 2 % bandwidth is fabricated and tested to verify the concept. The unique feature of the proposed tunable filter is that it requires only one tuning element. This reduces the number of moving parts, enhancing reliability and significantly reducing production cost.