Compact Wilkinson power divider with simultaneous bandpass response and harmonic suppression

In this paper, an integrated power divider/bandpass filter component is proposed for simultaneous size reduction and harmonic suppression. A stepped impedance interdigital coupling element is used to replace the conventional quarter wavelength impedance transforming section of the Wilkinson power divider, yielding not only selective bandpass response but also good power splitting performance. From the experimental results, the insertion loss of a 2.4 GHz prototype is kept as low as 3.3 dB in the passband, and the isolation is 20.6 dB. The first spurious passband is recorded at 3.4f₀. These indexes show the significance of the proposed integrated component.