Adaptive antenna neutralization network

1. An adaptive antenna neutralization network (AANN) for neutralizing coupling between a first antenna coupled to a first radio and a second antenna coupled to a second radio of a mobile terminal, the AANN comprising:

an array of reactive branches, each reactive branch including a reactive element and an electrically controlled switch with a control input for selectively coupling the reactive element between the first antenna and the second antenna;

a switch driver having an output coupled to the control input of each electrically controlled switch; and

a controller having an output for sending control signals to the switch driver to turn on or off the electrically controlled switch of each reactive branch selected to produce anti-resonance to block an interfering signal from reactively coupling between the first antenna and the second antenna in response to a feedback signal generated by at least one of the first radio and second radio.

2. The AANN of claim 1 , wherein the array of reactive branches is a programmable array of capacitors (PAC).

3. The AANN of claim 1 , wherein the array of reactive branches is a programmable array of inductors (PAI).

4. The AANN of claim 1 , wherein the array of reactive branches include inductors and capacitors.

5. The AANN of claim 1 , wherein the controller is adapted to receive control signals from a baseband (BB) generator.

6. The AANN of claim 5 , wherein the BB generator is adapted to execute a signal to noise (S/N) estimator that provides a discriminator function for a gradient search algorithm that selects appropriate reactive elements to couple between the first antenna and the second antenna to minimize antenna coupling.

7. The AANN of claim 1 , wherein a de-coupling of the first antenna and the second antenna is bi-directional.

8. A mobile terminal comprising:

a first antenna;

a first radio coupled to the first antenna;

a second antenna;

a second radio coupled to the second antenna; and

an adaptive antenna neutralization network (AANN) comprising:

an array of reactive branches, each reactive branch having a reactive element and an electrically controlled switch with a control input for selectively coupling the reactive element between the first antenna and the second antenna;

a switch driver having an output coupled to the control input of each electrically controlled switch; and

a controller having an output for sending control signals to the switch driver to turn on or off the electrically controlled switch of each reactive branch selected to produce anti-resonance to block an interfering signal from reactively coupling between the first antenna and the second antenna in response to a feedback signal generated by at least one of the first radio and second radio.

9. The mobile terminal of claim 8 , wherein the array of reactive branches is a programmable array of capacitors (PAC).

10. The mobile terminal of claim 8 , wherein the array of reactive branches is a programmable array of inductors (PAI).

11. The mobile terminal of claim 8 , wherein the array of reactive branches include inductors and capacitors.

12. The mobile terminal of claim 8 , wherein the controller includes an input for receiving external control signals from a baseband (BB) generator.

13. The mobile terminal of claim 12 , wherein the BB generator is adapted to execute a signal to noise (S/N) estimator that provides a discriminator function for a gradient search algorithm that selects appropriate reactive elements to couple between the first antenna and the second antenna to achieve a minimum antenna coupling.

14. The mobile terminal of claim 8 , wherein a de-coupling of the first antenna and the second antenna is bi-directional.

15. An adaptive antenna neutralization network (AANN) for neutralizing coupling between a first antenna coupled to a first radio and a second antenna coupled to a second radio of a mobile terminal, the AANN comprising:

an array of reactive branches, each reactive branch including a reactive element and an electrically controlled switch with a control input for selectively coupling the reactive element between the first antenna and the second antenna;

a switch driver having an output coupled to the control input of each electrically controlled switch;

a first inductor selectively coupled between the array of reactive branches and the first antenna via a first switch that is in series with the first inductor;

a second inductor selectively coupled between the array of reactive branches and the second antenna via a second switch that is in series with the second inductor; and

a controller having an output for sending control signals to the switch driver to turn on or off the electrically controlled switch of each reactive branch selected to produce anti-resonance to block an interfering signal from reactively coupling between the first antenna and the second antenna in response to a feedback signal generated by at least one of the first radio and second radio.

16. The AANN of claim 15 , further including a capacitor coupled in parallel with the first inductor to provide a parallel resonance to block a signal that is transmitted from the first antenna from entering the array of reactive branches.

17. The AANN of claim 15 , wherein the array of reactive branches is a programmable array of capacitors (PAC).

18. The AANN of claim 15 , wherein the controller is adapted to receive control signals from a baseband (BB) generator.

19. The AANN of claim 18 , wherein the BB generator is adapted to execute a signal to noise (S/N) estimator that provides a discriminator function for a gradient search algorithm that selects appropriate reactive elements to couple between the first antenna and the second antenna to minimize antenna coupling.