Wide-band rotary transformer—Unbalanced current analysis

Performance of a wide-band rotary transformer with approximately 1000:1 bandwidth (80 kHz-80 MHz) is described. A previous paper [1] gave theoretical analysis and experimental results based upon lossless balanced, transmission line theory. This paper extends the results to the case of a shielded transformer, and uses a combination of balanced and unbalanced line theory to account for losses and predict frequency response. Theoretical results are confirmed by data measured on a prototype coupler.