Slot antenna having a MEMS varactor for resonance frequency tuning

• US 20060125703A1
• Filed: 12/14/2004
• Published: 06/15/2006
• Est. Priority Date: 12/14/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Ma, Qing, Lin, Xintian Eddie, Bettner, Al
• Granted Patent: US 7,348,928 B2
• Time in Patent Office: Days
• US Class Current: 343/767
• CPC Class Codes: H01Q 13/103 with variable reactance for tuning the antenna tuning resonant circuits H03J

Abstract

Briefly, in accordance with one embodiment of the invention, a slot antenna may include a primary slot and one or more secondary slots. The size of the antenna may be reduced by adding one or more of the secondary slots which may add additional inductance to the antenna. Furthermore, the size of the antenna may be reduced by increasing the inductance of the secondary slots via increasing the length of the slots or by changing the shape of the slots. The antenna may include one or more MEMS varactors coupled to one or more of the secondary slots. The resonant frequency of the slot antenna may be tuned to a desired frequency by changing the capacitance value of one or more of the MEMS varactors to a desired capacitance value.

Claims

1. An apparatus, comprising:

a antenna layer having a primary slot formed in the antenna layer, and one or more secondary slots formed in the antenna layer to form a slot antenna; and

one or more varactors coupled to one or more of the secondary slots to tune the slot antenna to a desired frequency via selection of a capacitance of one or more of the varactors.

2. An apparatus as claimed in claim 1, wherein the varactors are microelectromechanical system structures.

3. An apparatus as claimed in claim 1, wherein the slot antenna may be tuned to a channel of a cellular communication system via the varactors.

4. An apparatus as claimed in claim 1, wherein the slot antenna may be tuned to a channel of a wireless local area communication system via the varactors.

5. An apparatus as claimed in claim 1, wherein the one or more of the secondary slots is folded to provide an increased inductance for the secondary slot.

6. An apparatus as claimed in claim 1, wherein the slot antenna has a higher Q value based a higher Q value of the varactors.

7. An apparatus as claimed in claim 1, wherein an inductance of the secondary slots in combination with a capacitance of the varactors give the slot antenna a narrow band characteristic.

8. An apparatus as claimed in claim 1, wherein one or more of the varactors has a continuously selectable capacitance value.

9. An apparatus as claimed in claim 1, wherein one or more of the varactors has a discrete valued selectable capacitance.

10. An apparatus as claimed in claim 1, wherein one or more of the varactors comprises a network of selectable capacitors to provide a stepped variable capacitance value.

20. An apparatus as claimed in claim 1, wherein the slot antenna has a higher Q value based a higher Q value of the varactors.

11. A method, comprising:

determining a desired frequency on which to operate a slot antenna;

tuning a slot antenna to the frequency determined in said determining by selecting a capacitance value of a varactor coupled to an inductive slot of the slot antenna; and

operating the slot antenna at the desired frequency.

12. A method as claimed in claim 11, wherein said tuning includes modifying an inductance value of the antenna via modifying the capacitance value of the varactor.

13. A method as claimed in claim 11, wherein said tuning includes increasing the capacitance value of the varactor to increase a resonant frequency of the slot antenna.

14. A method as claimed in claim 11, wherein said tuning includes decreasing the capacitance value of the varactor to decrease the resonant frequency of the slot antenna.

15. An apparatus, comprising:

a baseband processor to process baseband cellular telephone information;

a transceiver to couple to the baseband processor; and

a slot antenna to couple to the transceiver, wherein the slot antenna comprises;

a antenna layer having a primary slot formed in the antenna layer, and one or more secondary slots formed in the antenna layer to form a slot antenna; and

one or more varactors coupled to one or more of the secondary slots to tune the slot antenna to a desired frequency via selection of a capacitance of one or more of the varactors.

16. An apparatus as claimed in claim 15, wherein the varactors are microelectromechanical system structures.

17. An apparatus as claimed in claim 15, wherein the slot antenna may be tuned to a channel of a cellular communication system via the varactors.

18. An apparatus as claimed in claim 15, wherein the slot antenna may be tuned to a channel of a wireless local area communication system via the varactors.

19. An apparatus as claimed in claim 15, wherein the one or more of the secondary slots is folded to provide an increased inductance for the secondary slot.

21. An apparatus as claimed in claim 15, wherein an inductance of the secondary slots in combination with a capacitance of the varactors give the slot antenna a narrow band characteristic.

22. An apparatus as claimed in claim 15, wherein one or more of the varactors has a continuously selectable capacitance value.

23. An apparatus as claimed in claim 15, wherein one or more of the varactors has a discrete valued selectable capacitance.

24. An apparatus as claimed in claim 15, wherein one or more of the varactors comprises a network of selectable capacitors to provide a stepped variable capacitance value.