Ultra-wideband, Low-loss, and High-isolation Wilkinson Power Divider Using the Multiple Resonant Technique

This paper introduces a novel ultra-wideband (UWB) Wilkinson power divider (WPD) employing the multiple resonant technique to achieve 100% fractional bandwidth (FBW). To enhance the output return-loss bandwidth, both parallel and series resonators are incorporated at the output ports, while a series resonator is utilized at the input port to improve input matching. The proposed UWB WPD is fabricated using the WIN integrated passive devices (WIPD) process and occupies a chip area of 1.188 mm². Measurement results show that the insertion loss remains between 3.4 and 3.95 dB, with return loss exceeding 20 dB across the 6–18 GHz frequency range. Furthermore, the isolation exceeds 18.2 dB throughout the operating band. These results confirm that the proposed design achieves an exceptionally large FBW of 100%, demonstrating its suitability for wideband RF and microwave applications.