Wideband filtering power divider with high selectivity

A wideband filtering power divider (PD) with high selectivity is introduced, based on a terminated coupled line structure. The bandwidth tuning, isolation and impedance matching performances optimisation are presented and explained. Finally, the filtering PD is designed and implemented with a centre frequency (f₀) of 3.0 GHz and a fractional bandwidth of 70%. The upper stopband is achieved up to 2.6 f₀, with a rejection of better than 13 dB. The measured minimum in-band insertion loss is 0.3 dB (not including the splitting loss). Isolation of higher than 16.7 dB between the output ports is observed up to 2.7 f₀.