TY - JOUR A2 - Liseno, Angelo AU - Guan, Xuehui AU - Gui, Ping AU - Xiong, Tao AU - Ren, Baoping AU - Zhu, Lei PY - 2017 DA - 2017/07/31 TI - Hybrid Microstrip/Slotline Ultra-Wideband Bandpass Filter with a Controllable Notch Band SP - 2398610 VL - 2017 AB - An ultra-wideband (UWB) bandpass filter (BPF) with a controllable notch band is presented by using hybrid microstrip/slotline structure. Firstly, a slotline resonator with symmetrically loaded stubs is fed by two microstrip lines to produce a UWB bandpass filtering response. Secondly, a microstrip triangular loop resonator is externally loaded over the slotline, and a notch band is introduced in the UWB passband. The notch band is determined by the perimeter of the loop resonator. Thirdly, two patches are added as the perturbation element to the corners of the microstrip resonator to excite a pair of degenerate modes. Bandwidth of the notch band can be tuned by properly selecting the patch size. Circuit model for the microstrip resonator loaded slotline is given and studied. Finally, the filter is designed, simulated, and measured. Measured results have agreed well with the simulated ones, demonstrating that a UWB filter with a controllable notch band has been realized. SN - 1687-5869 UR - https://doi.org/10.1155/2017/2398610 DO - 10.1155/2017/2398610 JF - International Journal of Antennas and Propagation PB - Hindawi KW - ER -