Synthesis and Design of Non-Equiripple Filter with Composite Coplanar Waveguide and Slotlines

This conference paper presents synthesis and design process for equiripple and non-equiripple bandpass filters using composite coplanar waveguide (CPW) and slotlines. The proposal of the non-equiripple filter is to reduce the manufacturing sensitivity and ensure the better in-band responses. A set of nonlinear equations are derived to obtain the coefficients of the characteristic function (CF) of the non-equiripple filter. Based on the derived normalized characteristic impedances, equiripple and non-equiripple CPW-based filters are designed, simulated and fabricated. The simulated and measured results show that the non-equiripple filter has a lower insertion loss than the equiripple one near the band edge and demonstrate the reduced sensitivity to manufacturing errors of non-equiripple filter.