Design of Length-Saving Multiway Wilkinson Power Dividers

A conventional multiway Wilkinson power divider must include transmission lines with a quarter of the wavelength. The prior miniaturized versions can further shorten the quarter-wave lines by adopting synthesized transmission lines, but the resulted shrunk operation bandwidth has not been considered as part of design. This paper introduces a method of designing the proposed length-saving multiway power divider to achieve targeted bandwidth performance with the minimum required total length. The proposed multiway power divider, including transmission lines with flexible lengths and additional matching capacitors, has the adjustable total length that can be set to the optimum value according to the generated plot mapping the corresponding bandwidths to the selected total lengths. The background principle, the theoretical analyses, and the design procedure of the proposed idea are addressed in detail. The design examples of the four-way, eight-way, and 32-way power dividers are provided. A 1-GHz eightway power divider prototype based on the proposed design method is fabricated. The measurements, decently matching with simulations and the theoretical prediction, show an expected 51% operation bandwidth with the total length reduced to 72% of the conventional value.