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 for mechanically scanned, multichannel radars. The main goal of the analysis is to develop a better understanding for the 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, the author determines the type of ring network needed for low channel loss and small rotational variations of this loss. Measurements on some test models support the predictions of the analysis. >