Wide-stopband Wilkinson power divider with bandpass response

A wide-stopband Wilkinson power divider with bandpass response and good isolation is presented. A 3-terminal, 2-pole bandpass filter and two 3-pole lowpass filters are used to replace the two quarter-wavelength transformer in a conventional Wilkinson power. The divider consists of two shorted-circuited half-wavelength stepped-impedance resonators and two 3-pole microstrip stepped-impedance lowpass filters. Thus, the divider achieves not only a bandpass response but also a very wide stopband. For the upper stopband performance, the rejection level is >10 dB up to 22.2 times the centre frequency.