An analysis of a coupled-ring rotary joint design

A theoretical and experimental analysis of a coupled-ring rotary joint design is described. A rotary joint of this type is commonly used in multichannel radar designs. The main goal of the analysis is to develop a better understanding for transfer of energy through the joint´s highly coupled rings. The author considers the geometry of a typical single channel and then describes a coupled transmission line model for the coupled-ring network. Using the model, he determines the type of ring network needed for low channel loss and small rotational variations of this loss. A series of measurements on some test models supports the predictions of the analysis.<>