A miniaturized filtering power divider with wide stopband

This paper presents a miniaturized power divider integrated with wide-stopband bandpass responses. Two K-inverters with bandpass functions are utilized to replace the two quarter-wavelength transmission lines in the conventional Wilkinson power divider. The K-inverter consists of transmission lines and capacitors which can reduce the occupied area and suppress the high-order harmonics. Theoretical analysis is carried out and design equations are derived. For demonstration, a filtering power divider operating at 470 MHz is implemented with the wide stopband up to 4 GHz. The circuit size is 0.033 λg × 0.044 λg, featuring compact size.