Mobile handheld antenna for reading tags

1. A tag reader, comprising:

a. a mobile part including an antenna for positioning near a group of tags attached to items, transmitting a power signal to the tags and receiving a response from the tags; wherein the antenna has an internal impedance that increases or decreases responsive to objects located in its vicinity;

b. a reader base for providing the power signal to the mobile part and for storing and analyzing information read from tags; wherein the information includes an identification code of each tag;

c. a real-time antenna tuning circuit for adjusting the impedance of the antenna;

wherein the real time antenna tuning circuit includes a sensor for determining power return loss of the antenna in real time;

wherein the mobile part, reader base and real time antenna tuning circuit are wired together to transfer the power signal from the reader base to the antenna through the real-time antenna tuning circuit;

wherein the real-time antenna tuning circuit monitors the power signal and adjusts the impedance of the antenna responsive to determining the power return loss; and

wherein the mobile part includes a display that provides an indication if all the items attached to the group of tags were located; and

wherein the real-time antenna tuning circuit is installed in the mobile part and connected by a cable to the reader base.

2. A tag reader according to claim 1 , further comprising a docking station to position the mobile part in a stationary position to serve as a stationary reader of items in the vicinity of the reader.

3. A tag reader according to claim 1 , wherein the real-time antenna tuning circuit includes an array of controllable capacitors/resistors/inductors in sequence or in parallel that can each be turned on or off to increase or decrease the impedance of the antenna.

4. A tag reader according to claim 1 , wherein the real-time antenna tuning circuit includes an array of controllable capacitors in parallel that can each be turned on or off to increase or decrease capacitance of the antenna.

5. A tag reader according to claim 4 , wherein some of the capacitor of the array have distinct values.

6. A tag reader according to claim 1 , wherein the real-time antenna tuning circuit includes a motion detector.

7. A tag reader according to claim 6 , wherein the antenna impedance is adjusted only when the motion detector detects that the real-time antenna tuning circuit is in motion.

8. A tag reader according to claim 1 , wherein the real-time antenna tuning circuit adjusts the impedance of the antenna to keep the power return loss within pre-selected limits.

9. A tag reader according to claim 1 , wherein the real-time antenna tuning circuit adjusts the impedance of the antenna to keep the power return loss stable.

10. A method of reading tags by a tag reader having a reader base and a mobile part, comprising:

positioning the mobile part including an antenna near a group of tags attached to items; wherein the antenna has an internal impedance that increases or decreases responsive to objects located in its vicinity;

receiving by a real-time antenna tuning circuit connecting between the reader base and the mobile part a power signal from the reader base; wherein the real-time antenna tuning circuit is installed in the mobile part and connected by a cable to the reader base;

providing the power signal to the antenna of the mobile part and receiving a response from the antenna;

determining an antenna power return loss by a sensor in the real-time antenna tuning circuit from the provided signal and the response;

adjusting the antenna impedance responsive to the determination in real-time of the power return loss from the antenna;

reading information from the tags; wherein the information includes an identification code of each tag;

storing and analyzing the information to determine if all the tags of the group were located; and

wherein the mobile part includes a display that provides an indication if all the items attached to the group of tags were located.

11. A method according to claim 10 , wherein the real-time antenna tuning circuit includes an array of controllable capacitors/resistors/inductors in sequence or in parallel that can each be turned on or off to increase or decrease the impedance of the antenna.

12. A method according to claim 10 , wherein the real-time antenna tuning circuit includes an array of controllable capacitors in parallel that can each be turned on or off to increase or decrease capacitance of the antenna.

13. A method according to claim 12 , wherein some of the capacitor of the array have distinct values.

14. A method according to claim 10 , wherein the real-time antenna tuning circuit includes a motion detector.

15. A method according to claim 10 , wherein the antenna impedance is adjusted only when the motion detector detects that the real-time antenna tuning circuit is in motion.

16. A method according to claim 10 , wherein the real-time antenna tuning circuit adjusts the impedance of the antenna to keep the power return loss within pre-selected limits.

17. A method according to claim 10 , wherein the real-time antenna tuning circuit adjusts the impedance of the antenna to keep the power return loss stable.

18. A tag reader according to claim 1 , wherein the display is configured to show a picture of a missing item to help the user to locate the item.

19. A method according to claim 10 , wherein the display is configured to show a picture of a missing item to help the user to locate the item.

20. A method according to claim 10 , wherein the tag reader includes a docking station to position the mobile part in a stationary position to serve as a stationary reader of items in the vicinity of the reader.