Wideband Bias Tee Without Lumped Components

This article describes the design that won first place in the Student Design Competition for the 1-8 GHz Component Less Bias Tee at the 2024 IEEE International Microwave Symposium. The proposed design utilizes transmission lines fabricated on a single-layer PCB, where the parameters and substrate were selected based on the tradeoff between bandwidth and fabrication feasibility. Measurements show a high bandwidth-to-size ratio – a 3-dB bandwidth of 3.05 – 8.9 GHz within a PCB area of 4.5 mm × 20.5 mm. Additionally, this article explores alternative structures and examines the power-handling limitations for future component-less bias tee designs.