Miniaturized band-pass filters using closed-loop microstrip ring resonator with parallel-coupled feed
Athukorala, L. and Budimir, D. 2010. Miniaturized band-pass filters using closed-loop microstrip ring resonator with parallel-coupled feed. Microwave and Optical Technology Letters. 52 (6), pp. 1277-1280. https://doi.org/10.1002/mop.25188