Design of Compact Wideband Coupled Line BPF with Wide stop band

A compact band pass filter (BPF) is designed with coupled transmission lines for wider band width and also to have wide stop band response. The proposed filter is implemented using direct coupled transmission lines along with stubs. Conventional equations are used for the calculation of even & odd mode impedances, width and spacing between the coupled lines. The circuit simulation and EM layout results are well matched and it has been observed that, filter has a bandwidth of approximate to 5 GHz with an insertion loss of 0.5 dB in the pass band and return loss is less than 10 dB. The bandwidth of stop band is more than 2 GHz on both sides of the pass band. The dimensions of the filter are 7.3 mm X 27.8 mm.