Described herein are rotary transformers for coupling signals between components that rotate relative to one another. In an exemplary embodiment, a rotary transformer comprises a rotary shaft, a first magnetic core on the rotary shaft, and a first winding wound around the first magnetic core. The rotary transformer farther comprises a hollow second magnetic core, and a second winding wound along the inner wall of the second magnetic core. During operation, the first winding on the rotary shaft rotates within the second winding with the magnetic cores magnetically coupling signals between the two windings. Also, the first and second windings are closely spaced to provide capacitive coupling between the windings that extends the frequency response of the transformer. In one embodiment, the windings comprises substantially flat conductors wound in the shape of the windings. In another embodiment, each of the windings comprises circular loops connected by jogs.
