Design of the Filtering Power Divider With a Wide Passband and Stopband

The planar power divider with a wide passband/stopband and filtering characteristics is proposed in this letter. In order to increase the slope rate around the passband skirt, the modified parallel-coupled bandpass filter is adopted. Moreover, utilizing the stub-loaded resonator within the filter, a wide passband can be achieved. Furthermore, the stopband bandwidth and attenuation can be extended with the stepped-impedance coupled lines. An exemplary design of the filtering power divider operated at 2 GHz is presented. In addition, the measured fractional bandwidth at 3 dB and attenuation in the stopband are 57.1% and 40 dB, respectively.