Wideband Bandpass HMSIW Filter with Dual Passbands using DGS and Slots

Bandpass filters with dual passbands have become a necessity of modern RF and wireless communications. A wideband half mode substrate integrated waveguide (HMSIW) filter is proposed and simulated using HFSS. The proposed design has DGS on the top and bottom planes. Transmission zeros are created to get double passbands. The top plane uses U-slots to create transmission zeros. A cascade of open loop resonators, open at both ends and containing horizontal slots is also etched in order to achieve strong rejection in stopband. CSRRs are etched in the bottom plane to produce desired passband characteristics. The proposed work produces a dual-band filter with simulated value of insertion loss is less than 1.5dB and return loss is well below 15dB in the passbands.