Antenna diversity system and slot antenna component

• US 8,531,337 B2
• Filed: 05/12/2006
• Issued: 09/10/2013
• Est. Priority Date: 05/13/2005
• Status: Active Grant

• Current Assignee: Fractus SA
• Original Assignee: Fractus SA
• Inventors: Soler Castany, Jordi, Mumbru Forn, Jos, Puente Baliarda, Carles
• Primary Examiner(s): Wimer, Michael C
• Assistant Examiner(s): ISLAM, HASAN Z
• Application Number:
  US11/914,178
• Publication Number:
  US 20080198082A1
• Time in Patent Office: 2,678 Days
• Field of Search: 343/700.MS, 343/767, 343/770, 343/893, 343/702, 343/846
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

The present invention refers to an antenna diversity system comprising at least a first antenna and a second antenna wherein the first antenna substantially behaves as an electric current source or as a magnetic current source, and the second antenna substantially behaves as an electric current source or as a magnetic current source and a corresponding wireless device. Further the invention relates to an SMT-type slot-antenna component comprising at least one conductive surface or sheet of metal in which the pattern of a slot is created, at least one contact terminal accessible from the exterior of said component to electrically connect the conductive surface included in the slot-antenna component with the ground plane of a circuit board such as a printed circuit board and a corresponding wireless device.

Claims

1. A wireless device including an antenna diversity system comprising:

a first antenna;

a second antenna; and

an elongated printed circuit board, said elongated printed circuit board including a ground plane common to the first antenna and the second antenna;

wherein the second antenna is a slot antenna forming a slot having an open end, said open end in contact with an edge of said ground plane;

wherein said slot is provided in a rectangular area having a longest dimension substantially parallel to a longest side of the elongated printed circuit board; and

wherein the first antenna is located proximate to a shortest side of the elongated printed circuit board.

2. The wireless device according to claim 1, wherein the first antenna is an electric current source.

3. The wireless device according to claim 2, wherein the first antenna is selected from a group comprising:

a monopole antenna, a patch antenna, an IFA, a PIFA and a multiband antenna.

4. The wireless device according to claim 3, wherein the first antenna is printed as a conductive layer on the elongated printed circuit board or is etched from a conductive layer of the elongated printed circuit board.

5. The wireless device according to claim 1, wherein said slot is inscribed in a rectangular area a width of which divided by a free-space operating wavelength of the slot antenna being smaller than, or equal to, at least one of the fractions of the group comprising:

1/10, 1/30, 1/50, 1/60, 1/70, or 1/80.

6. The wireless device according to claim 1, wherein said slot is inscribed in a rectangular area a length of which divided by a free-space operating wavelength of the slot antenna being smaller than, or equal to, at least one of the fractions of the group comprising:

½

, ⅓

, ¼

, ⅕

, ⅙

or ⅛

.

7. The wireless device according to claim 1, wherein the slot antenna is printed as a conductive layer on the elongated printed circuit board or etched from a conductive layer of the elongated printed circuit board.

8. The wireless device according to claim 7, wherein said conductive layer is the ground plane of the wireless device.

9. The wireless device according to claim 1, wherein the slot comprises a plurality of segments, and wherein at least two segments of said plurality of segments have different lengths.

10. The wireless device according to claim 9, wherein a separation between opposite edges of at least one segment is constant.

11. The wireless device according to claim 9, wherein a separation between opposite edges of at least one, two, three, four, or more segments is within a minimum and a maximum fraction of a free-space operating wavelength of said slot antenna, wherein said minimum and maximum fraction are selected from the set comprising:

0.08%, 0.16%, 0.32%, 0.5%, 1%, 2%, 4%, 6%, and 8%.

12. The wireless device according to claim 9, wherein the longest segment of the slot is substantially parallel to a longest symmetry axis of the elongated printed circuit board.

13. The wireless device according to claim 1, wherein the slot antenna is embedded in an SMT component.

14. The wireless device according to claim 13, wherein the slot comprises at least one curved segment.

15. The wireless device according to claim 14, wherein a separation between opposite edges of at least two segments is the same.

16. The wireless device according to claim 14, wherein a separation between opposite edges of at least one segment is within a minimum and a maximum fraction of a free-space operating wavelength of said slot antenna, wherein said minimum and maximum fraction are selected from the set comprising:

0.08%, 0.16%, 0.32%, 0.5%, 1%, 2%, 4%, 6%, and 8%.

17. The wireless device according to claim 14, wherein the longest segment, preferably the longest straight segment, of the slot is substantially parallel to the longest edge, extension or symmetry axis of the component.

18. The wireless device according to claim 13, wherein said open end is provided at an edge of the SMT component.

19. The wireless device according to claim 1, wherein the slot comprises a plurality of portions, and wherein at least two portions of said plurality of portions are parallel to each other.

20. The wireless device according to claim 1, wherein the area of a smallest possible rectangular area which completely encloses a perpendicular projection of the slot onto a plane of the elongated printed circuit board divided by the area of the elongated printed circuit board is equal to or less than a fraction of the group comprising:

⅕

, 1/7, 1/10, 1/15, 1/20, 1/15, 1/30, 1/40, 1/50, 1/60, 1/70, 1/80, 1/90, 1/100, 1/120, 1/140, 1/160, 1/180, 1/200, 1/250, 1/300, 1/400, 1/500, 1/1000.

21. The wireless device according to claim 2, wherein electric currents excited on at least a portion of the ground plane by the radiating mode of the first antenna are substantially parallel to magnetic currents excited on at least a portion of an extension of the second antenna.

22. The wireless device according to claim 13, wherein the first antenna is a slot antenna.

23. The wireless device according to claim 22, wherein a longest side of a smallest rectangle enclosing the first slot antenna is substantially perpendicular to a longest side of a smallest rectangle enclosing the second slot antenna.

24. The wireless device according to claim 22, wherein the first slot antenna comprises a second slot having an open end on a second edge of said ground plane, said second edge being substantially perpendicular to said edge.

25. The wireless device according to claim 13, wherein magnetic currents excited on at least a portion of an extension of the first antenna are substantially orthogonal to magnetic currents excited on at least a portion of an extension of the second antenna.

26. The wireless device according to claim 1, wherein the first antenna is radiating with a first polarization, and the second antenna is radiating with a second polarization, wherein the first polarization and the second polarization are substantially orthogonal.

27. The wireless device according to claim 1, wherein at least one of the first antenna and the second antenna is a multiband antenna, and wherein the first antenna and the second antenna have at least one frequency band in common.

28. The wireless device according to claim 1, wherein at least one of the first antenna and the second antenna is located on a corner of the elongated printed circuit board or not separated from said corner more than 1%, 5%, 10% or 20% of a longest extension of said elongated printed circuit board carrying the antennas.

29. The wireless device according to claim 1, wherein at least one of the first antenna and the second antenna is located on a side of the elongated printed circuit board carrying the antennas or not further separated from said side than 1%, 5%, 10% or 20% of a longest extension of the elongated printed circuit board.

30. The wireless device according to claim 1, wherein at least one of the first antenna and the second antenna is covering the middle of a side or is not more separated from the middle than 1%, 5%, 10% or 20% of a longest extension of the elongated printed circuit board.

31. The wireless device according to claim 1, wherein a separation between the first antenna and the second antenna is not more than a percentage of a longest extension of the elongated printed circuit board carrying the antennas, the percentage being chosen from the group comprising:

1%, 2%, 3%, 5%, 7%, 10%, 12%, 15%, 20%, 30%, 40% and 50%.

32. The wireless device according to claim 1, wherein a separation between the first antenna and the second antenna is more than a percentage of a longest extension of the elongated printed circuit board carrying the antennas, the percentage being chosen from the group comprising:

50%, 60%, 70%, 75%, 80%, 85%, 90% and 95%.

33. The wireless device according to claim 1, wherein at least one of the first antenna and the second antenna is integrated in a semiconductor package.

34. The wireless device according to claim 33, wherein said semiconductor package includes an electronic circuit.

35. The wireless device according to claim 34, wherein said electronic circuit comprises an electronic die.

36. The wireless device according to claim 1, wherein at least one of the said at least two antennas is operating not only in the same frequency band as the other antennas, but is also operating, at least, at some other frequency band used for mobile telephone systems.

37. The wireless device according to claim 1, wherein at least a portion of at least one of the first antenna and the second antenna is shaped as a space-filing curve, a box-counting, a grid dimension curve, a fractal curve, or a combination thereof.

38. The wireless device according to claim 1, wherein at least a portion of at least one of the first antenna and the second antenna is a polygonal or multilevel structure or coupled to a polygonal or multilevel structure.

39. The wireless device according to claim 1, wherein the first antenna is a magnetic current source.

40. The wireless device according to claim 1, wherein the slot antenna is a magnetic current source.

41. A wireless device including an antenna diversity system comprising:

a first antenna for transmitting and receiving electromagnetic waves in at least one frequency band;

a second antenna for receiving electromagnetic waves in the at least one frequency band;

an elongated printed circuit board, said elongated printed circuit board including a ground plane common to the first antenna and the second antenna;

wherein the first antenna is provided as an electric current source and the second antenna is provided as a magnetic current source;

wherein the first antenna and the second antenna receive simultaneously;

wherein the second antenna is a slot antenna comprising a slot;

wherein the first antenna is located proximate to a first side of the elongated printed circuit board and the second antenna is located proximate to a second side of the elongated printed circuit board;

wherein said first side is substantially perpendicular to said second side; and

wherein said slot is inscribed in a rectangular area having a longest dimension substantially parallel to the second side of the elongated printed circuit board.

42. The wireless device according to claim 41, wherein the device is at least one or a combination of wireless devices of a group of wireless devices comprising:

a cellular phone, a mobile phone, a handheld phone, a smart phone, a satellite phone, a multimedia terminal, personal digital assistant (PDA), a portable music player, a radio, a digital camera, a USB dongle, a wireless headset, an ear phone, a hands-free kit, an electronic game, a remote control, an electric switch, a light switch, an alarm, a car kit, a computer card, a PCMCIA card, a sensor, a headset, a dongle, a computer interface a computer mouse, a keyboard, a personal computer, a MP3 player, a portable DVD/CD player, a smoke detector, a switch, a motion sensor, a pressure sensor, a temperature sensor, a medical sensor, a meter, a short/medium range wireless connectivity application, a Mini-PCI, a Notebook, PC with WiFi module integrated, a compact flash wireless card, a UART dongle, a pocket PC with integrated Wi-Fi, an access point for a hot spot, a wireless wrist watch, a wireless wrist sensor, a bracelet FM radio, an MP3 player, a radio frequency identification tag, key remote entry system, an air pressure sensor e.g. in a tire, a radio controlled toy, a laptop and a cardbus 32 card.

43. The wireless device according to claim 42, wherein the device is configured for operation in one, two, three or more of the wireless communication systems preferably selected from the group comprising:

Bluetooth, 2.4 GHz Bluetooth, 2.4 GHz WiMAX, ZigBee, ZigBee at 860 MHz, ZigBee at 915 MHz, GPS, GPS at 1.575 GHz, GPS at 1.227 GHz, Galileo, GSM 450, GSM 850, GSM 900, GSM 1800, American GSM, DCS-1800, UMTS, CDMA, DMB, DVB-H, WLAN, WLAN at 2.4 GHz-6 GHz, PCS 1900, KPCS, WCDMA, SDARs, XDARS, DAB, WiFi, UWB, 2.4-2.483 GHz band, 2.471-2.497 GHz band, IEEE802.11ba, IEEE802.11b, IEEE802.11g and FM.

44. The wireless device according to claim 41, wherein the first antenna is selected from a group comprising:

a monopole antenna, a patch antenna, an IFA, a PIFA and a multiband antenna.

45. The wireless device according to claim 44, wherein the first antenna is printed as a conductive layer on the elongated printed circuit board or is etched from a conductive layer of the elongated printed circuit board.

46. The wireless device according to claim 41, wherein said slot is inscribed in a rectangular area a width of which divided by a free-space operating wavelength of the slot antenna being smaller than, or equal to, at least one of the fractions of the group comprising:

1/10, 1/30, 1/50, 1/60, 1/70, or 1/80.

47. The wireless device according to claim 41, wherein said slot is inscribed in a rectangular area a length of which divided by a free-space operating wavelength of the slot antenna being smaller than, or equal to, at least one of the fractions of the group comprising:

½

, ⅓

, ¼

, ⅕

, ⅙

or ⅛

.

48. The wireless device according to claim 41, wherein said slot antenna is printed as a conductive layer on the elongated printed circuit board or etched from a conductive layer of the elongated printed circuit board.

49. The wireless device according to claim 48, wherein said conductive layer is the ground plane of the wireless device.

50. The wireless device according to claim 41, wherein the slot comprises a plurality of segments, and wherein at least two segments of said plurality of segments have different lengths.

51. The wireless device according to claim 50, wherein a separation between opposite edges of at least one segment is constant.

52. The wireless device according to claim 50, wherein a separation between opposite edges of at least one, two, three, four, or more segments is within a minimum and a maximum fraction of a free-space operating wavelength of said slot antenna, wherein said minimum and maximum fraction are selected from the set comprising:

0.08%, 0.16%, 0.32%, 0.5%, 1%, 2%, 4%, 6%, and 8%.

53. The wireless device according to claim 50, wherein the longest segment of the slot is substantially parallel to a longest symmetry axis of the elongated printed circuit board.

54. The wireless device according to claim 41, wherein the slot has an open end which is provided at an edge of the ground plane.

55. The wireless device according to claim 41, wherein said slot antenna is embedded in an SMT component.

56. The wireless device according to claim 55, wherein the slot comprises at least one curved segment.

57. The wireless device according to claim 56, wherein a separation between opposite edges of at least two segments is the same.

58. The wireless device according to claim 56, wherein a separation between opposite edges of at least one segment is within a minimum and a maximum fraction of a free-space operating wavelength of said slot antenna, wherein said minimum and maximum fraction are selected from the set comprising:

0.08%, 0.16%, 0.32%, 0.5%, 1%, 2%, 4%, 6%, and 8%.

59. The wireless device according to claim 56, wherein the longest segment, preferably the longest straight segment, of the slot is substantially parallel to the longest edge, extension or symmetry axis of the component.

60. The wireless device according to claim 55, wherein an open end is provided at an edge of the SMT component.

61. The wireless device according to claim 41, wherein the slot comprises a plurality of portions, and wherein at least two portions of said plurality of portions are parallel to each other.

62. The wireless device according to claim 41, wherein the area of a smallest possible rectangular area which completely encloses a perpendicular projection of the slot onto a plane of the elongated printed circuit board divided by the area of the elongated printed circuit board is equal to or less than a fraction of the group comprising:

⅕

, 1/7, 1/10, 1/15, 1/20, 1/15, 1/30, 1/40, 1/50, 1/60, 1/70, 1/80, 1/90, 1/100, 1/120, 1/140, 1/160, 1/180, 1/200, 1/250, 1/300, 1/400, 1/500, 1/1000.

63. The wireless device according to claim 41, wherein electric currents excited on at least a portion of the ground plane by the radiating mode of the first antenna are substantially parallel to magnetic currents excited on at least a portion of an extension of the second antenna.

64. The wireless device according to claim 41, wherein the first antenna is radiating with a first polarization, and the second antenna is radiating with a second polarization, wherein the first polarization and the second polarization are substantially orthogonal.

65. The wireless device according to claim 41, wherein at least one of the first antenna and the second antenna is a multiband antenna.

66. The wireless device according to claim 41, wherein at least one of the first antenna and the second antenna is located on a corner of the elongated printed circuit board or not separated from said corner more than 1%, 5%, 10% or 20% of a longest extension of said elongated printed circuit board carrying the antennas.

67. The wireless device according to claim 41, wherein at least one of the first antenna and the second antenna is located on a side of the elongated printed circuit board carrying the antennas or not further separated from said side than 1%, 5%, 10% or 20% of a longest extension of the elongated printed circuit board.

68. The wireless device according to claim 41, wherein at least one of the first antenna and the second antenna is covering the middle of a side or is not more separated from the middle than 1%, 5%, 10% or 20% of a longest extension of the elongated printed circuit board.

69. The wireless device according to claim 41, wherein a separation between the first antenna and the second antenna is not more than a percentage of a longest extension of the elongated printed circuit board carrying the antennas, the percentage being chosen from the group comprising:

1%, 2%, 3%, 5%, 7%, 10%, 12%, 15%, 20%, 30%, 40% and 50%.

70. The wireless device according to claim 41, wherein a separation between the first antenna and the second antenna is more than a percentage of a longest extension of the elongated printed circuit board carrying the antennas, the percentage being chosen from the group comprising:

50%, 60%, 70%, 75%, 80%, 85%, 90% and 95%.

71. The wireless device according to claim 41, wherein at least one of the first antenna and the second antenna is integrated in a semiconductor package.

72. The wireless device according to claim 71, wherein said semiconductor package includes an electronic circuit.

73. The wireless device according to claim 72, wherein said electronic circuit comprises an electronic die.

74. The wireless device according to claim 41, wherein at least one of the said at least two antennas is operating not only in the same frequency band as the other antennas, but is also operating, at least, at some other frequency band used for mobile communication systems.

75. The wireless device according to claim 41, wherein at least a portion of at least one of the first antenna and the second antenna is shaped as a space-filing curve, a box-counting, a grid dimension curve, a fractal curve, or a combination thereof.

76. The wireless device according to claim 41, wherein at least a portion of at least one of the first antenna and the second antenna is a polygonal or multilevel structure or coupled to a polygonal or multilevel structure.

77. A wireless device including an antenna diversity system comprising:

a first antenna for transmitting and receiving electromagnetic waves in multiple frequency bands;

a second antenna for receiving electromagnetic waves in at least a frequency band;

wherein the second antenna is a slot antenna forming a slot having an open end, said open end in contact with an edge of said ground plane;

an elongated printed circuit board, said elongated printed circuit board including a ground plane common to the first antenna and the second antenna;

wherein the first antenna is inscribed in a rectangular area having a longest dimension substantially parallel to a first side of the elongated printed circuit board;

wherein the second antenna is inscribed in a rectangular area having a longest

dimension substantially parallel to a second side of the elongated printed circuit board;

wherein said first side is substantially perpendicular to said second side; and

wherein the first antenna and the second antenna have at least a receiving frequency range of a frequency band in common.

78. The wireless device according to claim 77, wherein the device is at least one of a group of wireless devices comprising:

a cellular phone, a mobile phone, a handheld phone, a smart phone, a satellite phone, personal digital assistant (PDA), a portable music player, a radio, a digital camera, a USB dongle, a wireless headset, an ear phone, a hands-free kit, an electronic game, a computer card, a PCMCIA card, a headset, a dongle, a personal computer, a Mini-PCI, a Notebook, a compact flash wireless card, a UART dongle, a pocket PC with integrated Wi-Fi, an access point for a hot spot, an MP3 player, a laptop, and a cardbus 32 card.

79. The wireless device according to claim 77, wherein the device is configured for operation in one, two, three or more of the wireless communication systems preferably selected from the group comprising:

Bluetooth, 2.4 GHz Bluetooth, 2.4 GHz WiMAX, ZigBee, ZigBee at 860 MHz, ZigBee at 915 MHz, GPS, GPS at 1.575 GHz, GPS at 1.227 GHz, Galileo, GSM 450, GSM 850, GSM 900, GSM 1800, American GSM, DCS-1800, UMTS, CDMA, DMB, DVB-H, WLAN, WLAN at 2.4 GHz-6 GHz, PCS 1900, KPCS, WCDMA, SDARs, XDARS, DAB, WiFi, UWB, 2.4-2.483 GHz band, 2.471-2.497 GHz band, IEEE802.11ba, IEEE802.11b, IEEE802.11g and FM.

80. The wireless device according to claim 77, wherein said second antenna is a multiband antenna operating in a plurality of frequency bands.

81. The wireless device according to claim 77, wherein said wireless device is a portable communications device.

82. The wireless device according to claim 81, wherein said portable communications device is a handset.

83. The wireless device according to claim 82, wherein at least one of the first antenna and the second antenna operates in at least two frequency bands within the 700 MHz 3600 MHz frequency range.

84. The wireless device according to claim 82, wherein at least one of the first antenna and the second antenna operates in at least four frequency bands within the 700 MHz 3600 MHz frequency range.

85. The wireless device according to claim 82, wherein at least one of the first antenna and the second antenna operates in at least one of the frequency bands used by at least a GSM or UMTS communication service.

86. The wireless device according to claim 82, wherein the first antenna and the second antenna operate at least one frequency band used by at least a GSM or UMTS communication service.

87. The wireless device according to claim 81, wherein the first antenna and the second antenna operate at least one frequency band used by at least a Bluetooth or WiFi connectivity service.

88. The wireless device according to claim 77, wherein the first antenna is an electric current source and the second antenna is a magnetic current source.

89. The wireless device according to claim 88, wherein the second antenna is a slot antenna.

90. The wireless device according to claim 88, wherein the first antenna is selected from a group comprising:

a monopole antenna, a patch antenna, an IFA, a PIFA and a multiband antenna.

91. The wireless device according to claim 90, wherein the first antenna is printed as a conductive layer on the elongated printed circuit board or is etched from a conductive layer of the elongated printed circuit board.

92. The wireless device according to claim 89, wherein said slot is inscribed in a rectangular area a width of which divided by a free-space operating wavelength of the slot antenna being smaller than, or equal to, at least one of the fractions of the group comprising:

1/10, 1/30, 1/50, 1/60, 1/70, or 1/80.

93. The wireless device according to claim 89, wherein said slot is inscribed in a rectangular area a length of which divided by a free-space operating wavelength of the slot antenna being smaller than, or equal to, at least one of the fractions of the group comprising:

½

, ⅓

, ¼

, ⅕

, ⅙

or ⅛

.

94. The wireless device according to claim 89, wherein the said slot antenna is printed as a conductive layer on the elongated printed circuit board or etched from a conductive layer of the elongated printed circuit board.

95. The wireless device according to claim 94, wherein said conductive layer is the ground plane of the wireless device.

96. The wireless device according to claim 89, wherein the slot has an open end which is provided at one edge of the ground plane.

97. The wireless device according to claim 89, wherein the slot antenna is embedded in an SMT component.

98. The wireless device according to claim 89, wherein the area of a smallest possible rectangular area which completely encloses a perpendicular projection of the slot onto a plane of the elongated printed circuit board divided by the area of the elongated printed circuit board is equal to or less than a fraction of the group comprising:

⅕

, 1/7, 1/10, 1/15, 1/20, 1/15, 1/30, 1/40, 1/50, 1/60, 1/70, 1/80, 1/90, 1/100, 1/120, 1/140, 1/160, 1/180, 1/200, 1/250, 1/300, 1/400, 1/500, 1/1000.

99. The wireless device according to claim 88, wherein electric currents excited on at least a portion of the ground plane by the radiating mode of the first antenna are substantially parallel to magnetic currents excited on at least a portion of an extension of the second antenna.

100. The wireless device according to claim 77, wherein the first antenna and the second antenna are magnetic current sources.

101. The wireless device according to claim 100, wherein the first and the second antenna are slot antennas.

102. The wireless device according to claim 101, wherein a longest side of a smallest rectangle enclosing the first slot antenna is substantially perpendicular to a longest side of a smallest rectangle enclosing the second slot antenna.

103. The wireless device according to claim 101, wherein the first slot antenna comprises a first slot having an open end on a first edge of said ground plane and the second slot antenna has an open end on a second edge of said ground plane, said first and second edges being substantially perpendicular.

104. The wireless device according to claim 100, wherein magnetic currents excited on at least a portion of an extension of the first antenna are substantially orthogonal to magnetic currents excited on at least a portion of an extension of the second antenna.

105. The wireless device according to claim 77, wherein the first antenna and the second antenna behave as electric current sources.

106. An antenna diversity system according to claim 105, wherein the electric currents excited on a printed circuit board, by the radiating mode of the first antenna, are substantially orthogonal to the electric currents excited on the said printed circuit board by the radiating mode of the second antenna, in at least a portion of the printed circuit board.

107. An antenna diversity system according to claim 105, wherein the first and/or the second antenna is selected from the group comprising:

a monopole antenna, patch antenna, IFA, a PIFA and a multiband antenna.

108. The wireless device according to claim 77, wherein the first antenna is radiating with a first polarization, and the second antenna is radiating with a second polarization, wherein the first polarization and the second polarization are substantially orthogonal.

109. The wireless device according to claim 77, wherein a separation between the first antenna and the second antenna is not more than a percentage of a longest extension of the elongated printed circuit board carrying the antennas, the percentage being chosen from the group comprising:

1%, 2%, 3%, 5%, 7%, 10%, 12%, 15%, 20%, 30%, 40% and 50%.

110. A wireless portable device comprising a circuit board and a slot-antenna component, wherein said circuit board comprises a ground plane, and wherein said slot-antenna component comprises:

at least one conductive surface, different from the ground plane of the circuit board, on which a pattern of a slot is created;

a dielectric substrate that backs said at least one conductive surface, or in which said at least one conducting surface is embedded;

at least one contact terminal named grounding terminal accessible from the exterior of said slot-antenna component to electrically connect said at least one conductive surface included in the slot-antenna component with the ground plane of the circuit board;

and at least one contact terminal named feeding terminal to couple a radio-frequency feeding signal from the outside of the slot-antenna component with the slot defined in said at least one conductive surface;

wherein said slot-antenna component has a rectangular shape with a length smaller than 1/10 of a free-space operating wavelength of the slot antenna, a width smaller than 1/15 of a free-space operating wavelength of the slot antenna and a height smaller than 1/60 of a free-space operating wavelength of the slot antenna;

wherein the unfolded length of the slot antenna comprising the slot created in said at least one conductive surface of the slot-antenna component is approximately a quarter of an operating wavelength of the slot antenna;

wherein at least a portion of the slot created in said at least one conductive surface of the slot-antenna component is shaped as a space-filling curve, or a box-counting curve, or a grid dimension curve;

wherein the slot-antenna component comprises a second grounding terminal;

wherein the first and second grounding terminals are close to two opposite edges of said slot-antenna component;

wherein the slot-antenna component comprises feeding means including a conductive strip connected to the at least one feeding terminal, and having a width smaller than 1/300 of a free-space operating wavelength of the slot antenna;

wherein said conductive strip is connected to an edge of the slot created in the at least one conductive surface of the slot-antenna component at a distance from a closed end of said slot smaller than 8% of a free-space operating wavelength of the slot antenna;

and wherein the wireless device is operating at one, two, three or more communication and connectivity services selected from the group comprising GSM850, GSM900, GSM1800, American GSM, PCS1900, GSM450, UMTS, WCDMA, CDMA, Bluetooth™

, IEEE802.11a, IEEE802.11b, IEEE802.11g, WLAN, WiFi, UWB, ZigBee, GPS, Galileo, SDARs, XDARS, WiMAX, DAB, FM, DMB, and DVB-H.