MAGNETIC COUPLING AND CANCELLATION ARRANGEMENT
An inductor arrangement comprises a first inductor formed on a substrate, a second inductor formed on the substrate, a first loop formed on the substrate adjacent to the first inductor and a phasing network connected to the first loop which is arranged to receive an input signal representative of a flow of magnetic flux through the second inductor and to apply a first current to the first loop for generating a flow of magnetic flux for reducing magnetic coupling between the second inductor and the first inductor. A second loop can be formed on the substrate adjacent to the second inductor which is arranged to generate a second current in response to a flow of magnetic flux through the second loop, with the second current being the signal representative of a flow of magnetic flux through the second inductor.
1 . An inductor circuit having a circuit for reducing parasitic coupling between inductors, the inductor circuit comprising:
a first inductor formed on a substrate;
a second inductor formed on the substrate, disposed a distance from the first inductor, configured to produce a magnetic flux, and parasitically coupled to the first inductor dependent at least in part on the magnetic flux;
a phasing network configured to receive an input signal representative of a magnetic flux through the second inductor and generate a compensation current dependent on the signal representative of the magnetic flux through the second inductor; and
a first loop coupled to the phasing network and configured to receive the compensation current, the first loop being disposed adjacent to the first inductor, the first loop configured to generate a compensating magnetic flux counter-phase to the magnetic flux.
2 . The inductor circuit of claim 1 , further comprising a second loop coupled to the phasing network, disposed adjacent the second inductor, and configured to provide to the phasing network the input signal representative of the magnetic flux through the second inductor.
3 . The inductor circuit of claim 2 , wherein the phasing network comprises a module arranged to sense a current flowing in the second loop and apply a gain to the current to generate the compensation current.
4 . The inductor circuit of claim 2 , wherein the phasing network comprises:
a first capacitor in series between a first end of the first loop and a first end of the second loop; and
a second capacitor in series between a second end of the first loop and a second end of the second loop.
5 . The inductor circuit of claim 2 , wherein the phasing network comprises a pair of cross-connects configured to couple respective ends of the first loop and the second loop to generate the compensating magnetic flux counter-phase to the magnetic flux.
6 . The inductor circuit of claim 1 , wherein the input signal representative of the magnetic flux through the second inductor comprise a current.
7 . The inductor circuit of claim 6 , wherein the current comprises an amplitude and a phase, and wherein the phasing network is configured to modify the amplitude and phase of the current to generate the compensating current.
8 . The inductor circuit of claim 7 , wherein the phasing network is configured to modify the amplitude and phase of the current to generate the compensating current in a frequency-selective manner.
9 . The inductor circuit of claim 1 , wherein the phasing network comprises an amplifier configured to receive a current representative of the magnetic flux through the second inductor and apply a gain to the current to generate the compensation current.
10 . An inductor circuit having a circuit for reducing parasitic magnetic coupling between inductors, the inductor circuit comprising:
a first inductor having a first plurality of windings formed on a substrate;
a second inductor having a second plurality of windings formed on the substrate and disposed a distance from the first inductor, such that parasitic magnetic coupling will occur between the second inductor and the first inductor; and
a cancellation circuit having,
a first loop formed on the substrate adjacent to and partially surrounding the first inductor and inductively coupled to the first inductor,
a second loop formed on the substrate adjacent to and partially surrounding the second inductor and inductively coupled to the second inductor,
a phasing network electrically coupling the first loop to the second loop, the phasing network configured to
receive an input current from the second loop based on a magnetic flux in the second inductor,
provide an output current to the first loop based on the input current,
induce a flow of additional magnetic flux in the first inductor based on the output current through the first loop, and
reduce the parasitic magnetic coupling based on the additional magnetic flux, the flow of additional magnetic flux being synchronous and opposite phase of the magnetic flux in the second inductor.
11 . The inductor circuit of claim 10 ,
wherein the first loop has a first end and a second end and the second loop has a first end and a second end, and
wherein the phasing network cross couples the first end of the first loop to the second end of the second loop and the second end of the first loop to the first end of the second loop.
12 . The inductor circuit of claim 10 ,
wherein the first loop has a first end and a second end and the second loop has a first end and a second end, and
the phasing network couples the first end of the first loop to the first end of the second loop via a first capacitive element and the second end of the first loop to the second end of the second loop via a second capacitive element.
13 . The inductor circuit of claim 10 , wherein the first loop comprises a different shape than the second loop.
14 . The inductor circuit of claim 10 , wherein the phasing network is further configured to modify a phase of the output current based on a phase of the input current.
15 . The inductor circuit of claim 10 , wherein the phasing network is further configured to modify an amplitude of the output current based on an amplitude of the input current.
16 . An inductor circuit having a circuit for reducing parasitic coupling between inductors, the inductor circuit comprising:
a first inductor formed on a substrate;
a second inductor formed on the substrate, disposed a distance from the first inductor, configured to produce a magnetic flux, and parasitically coupled to the first inductor dependent at least in part on the magnetic flux;
a phasing network configured to receive an input signal representative of a current through the second inductor and generate a compensation current dependent on the signal representative of the magnetic flux through the second inductor;
a first loop coupled to the phasing network and configured to receive the compensation current, the first loop being disposed adjacent to the first inductor, the first loop configured to generate a compensating magnetic flux counter-phase to the magnetic flux; and
a second loop coupled to the phasing network, disposed adjacent to the second inductor, and configured to generate, in dependence on the magnetic flux, an input current as the input signal to the phasing network.
17 . The inductor circuit of claim 16 , wherein the first inductor, second inductor, first loop, and second loop are formed on one layer, and the first loop is disposed laterally offset from the first inductor.
18 . The inductor circuit of claim 16 , wherein the first inductor is formed on a different layer from the first loop.
19 . The inductor circuit of claim 18 , wherein a track of the first inductor is vertically aligned with a track of the first loop.
20 . The inductor circuit of claim 16 , wherein the phasing network comprises at least one phase shifting component selected from the group consisting of a capacitive element, an inductive element, a resistive element, cross-connects, and a combination thereof.