Inductive structures with reduced emissions and interference

1. A device, comprising:

a first inductive structure including a first power coil and a first data coil, wherein: the first data coil is substantially centered within the first power coil; a first portion of the first data coil is for conducting current in a first direction; a second portion of the first data coil is for conducting current in a second direction opposite the first direction; the first portion of the first data coil is connected at a first node to the second portion of the first data coil; and the first node is coupled to a first ground; and

a second inductive structure including a second power coil and a second data coil, wherein: the second data coil is substantially centered within the second power coil; a first portion of the second data coil is aligned with the first portion of the first data coil for conducting current in the first direction; a second portion of the second data coil is aligned with the second portion of the first data coil for conducting current in the second direction; the first portion of the second data coil is connected at a second node to the second portion of the second data coil; and the second node is coupled to a second ground isolated from the first ground;

wherein the first power coil is for: receiving power without data from a transmitter; and outputting the power without data by inductive coupling to the second power coil; and

wherein the second power coil is for: receiving power without data by inductive coupling from the first power coil; and outputting the power without data to a receiver.

2. The device of claim 1 , and comprising:

an isolation barrier between the first and second inductive structures.

3. The device of claim 1 , wherein the first data coil is for: receiving data from a transmitter; and outputting the data by inductive coupling to the second data coil.

4. The device of claim 1 , wherein the second data coil is for: receiving data by inductive coupling from the first data coil; and outputting the data to a receiver.

5. The device of claim 1 , wherein the first and second inductive structures are substantially identical to one another.

6. The device of claim 5 , wherein the first and second portions the first data coil are substantially identical to one another, yet reversed from one another.

7. A method, comprising:

conducting current in a first direction through a first portion of a first data coil of a first inductive structure, wherein the first inductive structure includes a first power coil within which the first data coil is substantially centered;

with the first power coil, receiving power without data from a transmitter, and outputting the power without data by inductive coupling to the second power coil;

conducting current in a second direction through a second portion of the first data coil, wherein: the second direction is opposite the first direction; the first portion of the first data coil is connected at a first node to the second portion of the first data coil; and the first node is coupled to a first ground;

conducting current in the first direction through a first portion of a second data coil of a second inductive structure, wherein: the second inductive structure includes a second power coil within which the second data coil is substantially centered; and the first portion of the second data coil is aligned with the first portion of the first data coil;

with the second power coil, receiving power without data by inductive coupling from the first power coil, and outputting the power without data to a receiver; and

conducting current in the second direction through a second portion of the second data coil, wherein: the second portion of the second data coil is aligned with the second portion of the first data coil; the first portion of the second data coil is connected at a second node to the second portion of the second data coil; and the second node is coupled to a second ground isolated from the first ground.

8. The method of claim 7 , and comprising:

inductive coupling the first inductive structure to the second inductive structure, across an isolation barrier between the first and second inductive structures.

9. The method of claim 7 , and comprising:

with the first data coil, receiving data from a transmitter; and outputting the data by inductive coupling to the second data coil.

10. The method of claim 7 , and comprising:

with the second data coil, receiving data by inductive coupling from the first data coil; and

outputting the data to a receiver.

11. The method of claim 7 , wherein the first and second inductive structures are substantially identical to one another.

12. The method of claim 11 , wherein the first and second portions the first data coil are substantially identical to one another, yet reversed from one another.

13. A device, comprising:

a first inductive structure including a first power coil and a first data coil, wherein the first data coil has a symmetric 8-shape substantially centered within the first power coil;

a second inductive structure including a second power coil and a second data coil, wherein the second data coil has the symmetric 8-shape substantially centered within the second power coil, and wherein the first and second data coils are aligned with one another;

an isolation barrier between the first and second inductive structures;

wherein the first power coil is for: receiving power without data from a transmitter; and outputting the power without data by inductive coupling across the isolation barrier to the second power coil;

wherein the second power coil is for: receiving the power without data by inductive coupling across the isolation barrier from the first power coil; and outputting the power without data to a receiver;

wherein the first data coil is for: receiving data from the transmitter; and outputting the data by inductive coupling across the isolation barrier to the second data coil; and

wherein the second data coil is for: receiving the data by inductive coupling across the isolation barrier from the first data coil; and outputting the data to the receiver.

14. The device of claim 13 , wherein the first and second inductive structures are substantially identical to one another.

15. The device of claim 13 , wherein a center of the symmetric 8-shape of the first data coil is coupled to a first ground; and a center of the symmetric 8-shape of the second data coil is coupled to a second ground isolated from the first ground.