A new ultra-wideband parallel coupled line microstrip bandpass filter

Bandpass filter is presented based on parallel coupled line microstrip structure suitable for wireless communication applications. Chebyshev filter of order 4 and 0.2 dB passband ripple with fractional bandwidth of 52.17 % is designed using insertion loss method. The proposed filter demonstrated excellent ultra-wide bandwidth from 6 GHz to 16 GHz. The analysis of the filter is performed by using MoM based electromagnetic solver, IE3D. With the above structural features the overall dimension of the filter is 23 mm (height) × 4 mm (length) × 1.6 mm (breadth). It is not only compact but also delivers excellent scattering parameters with the magnitude of insertion loss, |S₂₁| lower than -1.2 dB and return loss better than -19.42 dB. In the passband the measured group delay varies in between 0 ns and 0.15 ns, showing stability with minimum variation of only 0.15 ns.