Wideband Four-Way Filtering Power Divider Using Simple Three-Line Coupled Structures

Two quarter-wavelength three-line coupled structures (TLCSs) are employed in the design of filtering power divider (FPD) to achieve a wide fractional bandwidth and good out-of-band rejection. The center frequency of the FPD passband can be adjusted flexibly by changing the length of the TLCS while the fractional bandwidth will remain unchanged. The frequency selectivity and passband bandwidth of the FPD can be easily controlled with the variations of the TLCS width and gap, respectively. Furthermore, the proposed FPD topology can be extended to design a four-way FPD through adding two conventional Wilkinson power dividers. This four-way FPD is fabricated with the center frequencies of 2.42 GHz and 3-dB fractional bandwidths of over 100%. The simulated and measured results are compared with good agreement.