— This study presents a novel switchable dual-band filter. An original concurrent dual-band filter uses a hybrid feeding structure such that the external quality factors of the two designated bands can be obtained individually. Therefore, there is no need for a dual-band impedance transformer and time-consuming parameter tuning is avoided. Stepped-impedance quarter-wavelength resonators are used to reduce the circuit size. Two types of switching circuit are added to the original concurrent dual-band filter to obtain a switchable dual-band filter. The proposed switchable dual-band filter has four possible operating states and thus the two passbands can be enabled or disabled independently.
— Switchable dual-band filter, stepped-impedance resonator, quarter-wavelength resonator.
Ming-Lin Chuang, Ming-Tien Wu, and Pei-Ru Wu are with the Communication Engineering Department, National Penghu University of Science and Technology, Taiwan (e-mail: email@example.com).
Cite: Ming-Lin Chuang, Ming-Tien Wu, and Pei-Ru Wu, " Switchable Dual-Band Filter with Hybrid Feeding Structure," International Journal of Information and Electronics Engineering vol. 5, no. 2, pp. 79-83, 2015.