A method for determining an angular position of a rotatable inductive coupling element, the method comprising:
- establishing a magnetic coupling in a first annular sensor, the first annular sensor comprising a first planar excitation coil having a clockwise winding portion and a counter-clockwise winding portion and a first planar sensing coil pair, wherein both the clockwise winding portion and the counter-clockwise winding portion of the first planar excitation coil are positioned adjacent to a same side of the first planar sensing coil pair, and wherein the first planar sensing coil pair comprises a respective cosine sensing coil and a respective sine sensing coil, each of the respective cosine sensing coil and the respective sine sensing coil of the first planar sensing coil pair comprising a respective clockwise winding portion and a respective counter-clockwise winding portion;
- establishing a magnetic coupling in a second annular sensor positioned to surround the first annular sensor, the second annular sensor comprising a second planar excitation coil having a clockwise winding portion and a counter-clockwise winding portion and a second planar sensing coil pair, wherein both the clockwise winding portion and the counter-clockwise winding portion of the second planar excitation coil are positioned adjacent to a same side of the second planar sensing coil pair, and wherein, the second planar sensing coil pair comprises a respective cosine sensing coil and a respective sine sensing coil, each of the cosine sensing coil and the sine sensing coil of the second planar sensing coil pair comprising a respective clockwise winding portion and a respective counter-clockwise winding portion;
- positioning a rotatable inductive coupling element in overlying relation to, and separated from the first annular sensor and the second annular sensor, the rotatable inductive coupling element comprising a first annular portion comprising at least one annular conductive sector and at least one annular non-conductive sector and a second annular portion comprising at least one annular conductive sector and at least one annular non-conductive sector, and wherein a number of annular conductive sectors of the second annular portion is different than a number of annular conductive sectors of the first annular portion;
- rotating the rotatable inductive coupling element to generate coarse resolution sine and cosine signals having a number of cycles per rotation of the rotatable inductive coupling element equal to a number of annular conductive sectors of a first one of the first annular portion and the second annular portion of the rotatable inductive coupling element and to generate fine resolution sine and cosine signals having a number of cycles per rotation of the rotatable inductive coupling element equal to a number of annular conductive sectors of a second one of the first annular portion and the second annular portion of the rotatable inductive coupling element;
- and
- determining an angular position of the rotatable inductive coupling element using the coarse resolution sine and cosine signals and the fine resolution sine and cosine signals.