A Compact, Wideband Lumped-Element Wilkinson Power Divider/Combiner Using Symmetric Inductors with Embedded Capacitors

A compact, wideband, and low loss multi-section lumped-element Wilkinson power divider/combiner (WPDC) is reported in this letter. The cascade of four λ/16 LC π-networks for a λ/4 transformer of WPDC, realized by a symmetric inductor with an embedded capacitor technique, can achieve broadband operation and low insertion loss (IL) while saving Si die area. The measured results show a minimum IL of 0.45 dB at 10 GHz. In addition, the IL lower than 1 dB, the isolation (ISO) better than 10 dB, and return losses (RL) higher than 10 dB are satisfied from 5.2 GHz to 18.8 GHz, demonstrating the proposed scheme is applicable to wideband operation. The measured amplitude and phase error are within 0.06 dB and 1.0 degree from DC to 20 GHz, respectively. The core chip size is 0.32 × 0.34 mm
²
. To the authors' best knowledge, the proposed WPDC shows the lowest IL and widest band operational capability for all published Si-based WPDCs, and thus proves useful for low-cost, highly-integrated phased array and wireless communications systems.