How To Make An RF Or Microwave Power Splitting Network

By Doug Jorgesen

In microwave and RF systems, designing efficient power-splitting networks is critical, as they are widely used in applications like phased array radar, clock distribution, and MIMO systems. This case study examines a specific 8-way power-splitting network for 6-20 GHz, evaluating different configurations that incorporate Wilkinson and resistive power dividers, along with optional amplifiers, attenuators, and equalizers. Ten designs are analyzed, focusing on essential parameters such as insertion loss, return loss, isolation, and phase and amplitude balance.

Cascading Wilkinson dividers results in low insertion loss and high isolation but may create standing waves that worsen return loss and insertion loss ripples. Staggered spacing or an integrated four-way Wilkinson divider can mitigate these issues but at the expense of layout flexibility and phase balance. Conversely, resistive dividers provide better insertion loss flatness and return loss but with higher overall loss and lower isolation. Integrating resistive dividers with Wilkinson dividers achieves optimal performance across specifications. Amplifiers enhance signal gain and isolation, though they complicate layout, while attenuators and equalizers help match impedances but add loss.

For applications demanding high isolation, match quality, and phase stability, the study suggests carefully balancing these components to optimize the network's output, particularly recommending mixed configurations of Wilkinson and resistive dividers for enhanced performance across different scenarios.