Multiband antenna system and methods

• US 20080303729A1
• Filed: 04/03/2008
• Published: 12/11/2008
• Est. Priority Date: 10/03/2005
• Status: Active Grant

• Current Assignee: Antti Leskela, Pertti Nissinen, Petteri Annamaa, Zlatoljub Milosavljevic
• Original Assignee: Pulse Finland Oy (Yageo Corporation)
• Inventors: Nissinen, Pertti, Annamaa, Petteri, Milosavljevic, Zlatoljub, Leskela, Antti
• Granted Patent: US 7,889,143 B2
• Time in Patent Office: Days
• US Class Current: 343/722
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 5/378 Combination of fed elements with parasitic elements
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/145 by varying the electrical length

Abstract

An antenna system internal to a radio device, the system comprising separate antennas and having separate operating bands. The system is implemented as decentralized in a way that each antenna is typically based on a small-sized chip component (310; 320; 330; 340; 350; 360; 610), which are located at suitable places on the circuit board (PCB) and possibly on also another internal surface in the device. The chip component comprises a ceramic substrate and at least one radiating element. The operating band of an individual antenna covers e.g. the frequency range used by a radio system or only the transmitting or receiving band in that range. At least one antenna is connected to an adjusting circuit with a switch, by which the antenna'"'"'s operating band can be displaced in a desired way. In this case the operating band covers at a time a part of the frequency range used by one or two radio systems. The antennas can be made small-sized, because a relatively small bandwidth is sufficient for an individual antenna, when there is a plurality of antennas. When the bandwidth is small, a material with higher permittivity can be chosen for the antenna than for an antenna having a wider band, in which case the antenna dimensions can be made correspondingly smaller. In addition, a good matching of the antenna is achieved on the whole width of each radio system, because the matching of a separate antenna having a relatively narrow band is easier to arrange than that of a combined multiband antenna.

Claims

1-13. -13. (canceled)

14. An adjusting circuit for use with an antenna system of a radio device, said adjusting circuit comprising:

an input electrically coupled to an antenna component;

a filter circuit;

a switching circuit; and

a plurality of reactive circuits each coupled to an end of said switching circuit.

15. The adjusting circuit of claim 14, wherein said plurality of reactive circuits each comprise a different operating band.

16. The adjusting circuit of claim 15, wherein the number of said plurality of reactive circuits is three.

17. The adjusting circuit of claim 14, wherein each of said plurality of reactive circuits is further coupled to ground.

18. The adjusting circuit of claim 14, wherein said filter circuit is adapted to attenuate at least a portion of harmonic frequency components that develop within said switching circuit.

19. The adjusting circuit of claim 18, wherein said filter circuit further comprises electrostatic discharge (ESD) protection.

20. The adjusting circuit of claim 14, wherein the positioning of said switching circuit is controlled by a control signal.

21. The adjusting circuit of claim 14, wherein at least one of said plurality of reactive circuits comprises an inductive reactance.

22. The adjusting circuit of claim 21, wherein at least one of said plurality of reactive circuits comprises a capacitive reactance.

23. The adjusting circuit of claim 14, wherein each of said plurality of reactive circuits comprises a transmission line coupled to ground.

24. The adjusting circuit of claim 23, wherein each of said transmission lines for said plurality of reactive circuits is of a differing length.

25. The adjusting circuit of claim 14, wherein each of said plurality of reactive circuits is adapted for a plurality of separate operating applications.

26. The adjusting circuit of claim 25, wherein said plurality of separate operating applications are selected from the group consisting of:

a GSM850 application;

a GSM900 application;

a GSM1800 application;

a GSM1900 application; and

a WCDMA application.

27. A method of operating an antenna system of a radio device, said antenna system comprising a ground plane, an antenna and an adjusting circuit, said method comprising:

operating said antenna system in a first mode of operation;

sending a control signal to said adjusting circuit, said control signal switching an operating mode of said adjusting circuit; and

operating said antenna system in a second mode of operation, said first and second modes of operation utilizing the same antenna.

28. The method of claim 27, wherein said first and second modes of operation comprise the GSM850 and GSM900 modes of operation, respectively.

29. The method of claim 27, wherein said first and second modes of operation comprise the GSM1800 and GSM1900 modes of operation, respectively.

30. The method of claim 27, further comprising operating said antenna system in a third mode of operation, said third mode of operation using the same antenna as said first and second modes of operation.

31. The method of claim 30, wherein said first, second and third modes of operation comprise the GSM850 receiving band, GSM900 transmitting band and GSM900 receiving bands, respectively.

32. An antenna system of a radio device, said system comprising:

a ground plane;

at least two antennas each comprising a radiating element, wherein each radiating element comprises a conductor on a surface of a dielectric substrate;

wherein a distance along said ground plane between two of said radiating elements belonging to different antennas is at least the combined length of these two radiating elements; and

wherein at least one antenna is connected to an adjusting circuit.

33. The antenna system of claim 32, wherein said adjusting circuit comprises:

a switching circuit; and

a plurality of reactive circuits each coupled to an end of said switching circuit.

34. The antenna system of claim 32, wherein at least one of the antennas is disposed on a surface of an internal frame of the radio device.

35. An antenna system of a radio device, which system comprises a ground plane and at least two antennas, each radiating element of which is a conductor on a surface of a dielectric substrate, characterized in that:

a distance along said ground plane between two radiating elements belonging to different ones of said antennas is at least the combined length of these radiators, and

at least one of said antennas is connected to an adjusting circuit adapted to displace an operating band thereof.

36. An antenna system according to claim 35, characterized in that the substrate of an individual one of said at least two antennas and the at least one radiating element on the surface of the substrate constitute a unitary, chip-type antenna component.

37. An antenna system according to claim 36, characterized in that said antenna component is located on a circuit board of the radio device.

38. An antenna system according to claim 36, characterized in that said antenna component is disposed on a surface of an internal frame of the radio device.

39. An antenna system according to claim 35, characterized in that an operating band of at least one of said at least two antennas comprises a frequency range used by at least one radio system.

40. An antenna system according to claim 35, wherein an operating band of at least one of said at least two antennas comprises a transmitting band in the frequency range used by a radio system, and an operating band of another one of said at least two antennas comprises a receiving band of the same frequency range.

41. An antenna system according to claim 40, wherein at least one of said at least two antennas comprises an operating band of which includes the receiving band of the frequency range used to implement a spatial diversity function.

42. An antenna system according to claim 35, wherein said adjusting circuit comprises a switch and alternative reactive circuits adapted to change a resonance frequency of at least one of the antennas so as to displace an operating band of the at least one antenna.

43. An antenna system according to claim 42, characterized in that said reactive circuits comprise planar transmission lines.

44. An antenna system according to claim 35, characterized in that said adjusting circuit is connected galvanically to a radiating element of one of said antennas.

45. An antenna system according to claim 35, characterized in that said substrate comprises a ceramic material.

46. An antenna system according to claim 35, characterized in that the substrate of an individual one of said at least two antennas comprises a part of an outer casing of the radio device.