Dualband Filter using Stub-Loaded Resonators

In this letter, we propose a dual-band filter using stub-loaded resonators. The dual-band filter is analysed by odd and even mode analysis. For the open loaded stub condition, the main line controls both the lower and upper frequencies and the stub only controls the upper band frequency. By contrast the main line effect both the lower and upper frequencies and the short stub only controls the lower band frequency for short loaded stub condition. So the each band can be tuned independently through changing the length of each stub. Then given work frequency bands, physical dimensions of the structure can be easily deduced. Thus, based on full-wave simulation, the proposed design is verified.