Multiband antenna formed of superimposed compressed loops

• US 20030098814A1
• Filed: 11/27/2001
• Published: 05/29/2003
• Est. Priority Date: 11/09/2001
• Status: Abandoned Application

• Current Assignee: Protura Wireless, Inc. (Safeguard Scientifics (Delaware), Inc.)
• Original Assignee: Protura Wireless, Inc. (Safeguard Scientifics (Delaware), Inc.)
• Inventors: Keller, Walter John III, Sivaraks, Jesada, Romero, Osbaldo Jose
• Application Number:
  US09/995,478
• Publication Number:
  US 20030098814A1
• Time in Patent Office: Days
• US Class Current: 343/742
• CPC Class Codes: H01Q 1/243 with built-in antennas
• 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 5/364 Creating multiple current paths
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

A compressed multiple band loop antenna that has multiple superimposed compressed loops. Each compressed loop is formed from numerous segments arrayed in multiple diverse directions so that the enclosed area of that loop and the overall size of the antenna are decreased. Multiple loops are arrayed and superimposed to provide multiple frequency bands of operation and are used to broaden the useful bandwidth of individual-bands. The small size of the compressed antenna facilitates its use in small mobile communications devices requiring internal antennas that operate in close proximity to conductive surfaces. Multiple loops are arrayed in several configurations that include nested and non-nested loops as well as closely located and spatially separated superimposed loops.

Claims

1. (Original) A loop antenna, for use with a communication device, operating for exchanging energy in bands of radiation frequencies, comprising,

connection means for conduction of electrical current,

two or more radiation loops wherein,

each loop includes a plurality of electrically conducting segments, each segment having a segment length, where the segments are electrically connected in series to said connection means to form a loop antenna for exchange of energy in one of said bands of radiation frequencies,

at least one of said loops has said segments arrayed in a compressed pattern,

said loops are superimposed whereby an area enclosed by one of said loops covers an area enclosed by another of said loops.

2. (Original) The loop antenna of claim 1 wherein said loops are nested where an area enclosed by one of said loops is within an area enclosed by another of said loops.

3. (Original) The loop antenna of claim 2 wherein a first one of said loops is offset from a second one of said loops by a gap.

4. (Original) The loop antenna of claim 3 wherein said gap is a tuned gap.

5. (Original) The loop antenna of claim 3 wherein said gap is a tuned gap of approximately 0.69 mm.

6. (Original) The loop antenna of claim 3 wherein said tuned gap is less than approximately 10 mm for a US PCS band operating from 1850 MHz to 1990 MHz, a European DCS band operating from 1710 MHz to 1880 MHz, a European GSM band operating from 880 MHz to 960 MHz and a US cellular band operating from 829 MHz to 896 MHz.

7. (Original) The loop antenna of claim 1 wherein said loops are nested in a single plane where an area enclosed by one of said loops is within an area enclosed by another of said loops.

8. (Original) The loop antenna of claim 7 wherein said plane is flat.

9. (Original) The loop antenna of claim 7 wherein said plane is curved.

10. (Original) The loop antenna of claim 1 wherein said loops are nested on the same layer supported by a dielectric substrate where an area enclosed by one of said loops is within an area enclosed by another of said loops.

11. (Original) The loop antenna of claim 1 wherein said loops are on different layers supported by a dielectric substrate.

12. (Original) The loop antenna of claim 1 wherein said loops include two or more loops where each of said loops is a 2-legged compressed loop antenna.

13. (Original) The loop antenna of claim 1 wherein said loops include two or more loops where each of said loops is a 3-legged compressed loop antenna.

14. (Original) The loop antenna of claim 1 wherein said loops include two or more loops where each of said loops is a 4-legged compressed loop antenna.

15. (Original) The loop antenna of claim 1 wherein said loops include two or more loops where each of said loops is a 5-legged compressed loop antenna.

16. (Original) The loop antenna of claim 1 wherein said loops include two or more loops where each of said loops is a 6-legged compressed loop antenna.

17. (Original) The loop antenna of claim 1 wherein said 6-legged compressed antenna has a snowflake pattern.

18. (Original) The loop antenna of claim 1 wherein said connection means includes a transmission line connected to said compressed antennas.

19. (Original) The loop antenna of claim 1 wherein said compressed antennas are mounted on a flexible dielectric substrate.

20. (Original) The loop antenna of claim 1 wherein a majority of said segments are straight and arrayed in multiple divergent directions not parallel to an orthogonal coordinate system so as to provide a long antenna electrical length while permitting the overall outside dimensions of said loop to fit within an antenna area of said communication device.

21. (Original) The loop antenna of claim 1 wherein said connection means includes contact areas for coupling to a transceiver of said communication device.

22. (Original) The loop antenna of claim 1 wherein said connection means includes at least one compressible metal tang.

23. (Original) The loop antenna of claim 1 wherein said connection means includes two compressible metal tangs that have substantially the same spring compression for making balanced electrical connections to first and second conductors.

24. (Original) The loop antenna of claim 1 wherein said radiation loop has an irregular shape and wherein said segments are arrayed in an irregular compressed pattern.

25. (Original) The loop antenna of claim 1 wherein said segments of one or more of said loops are situated on a flexible dielectric substrate.

26. (Original) The loop antenna of claim 1 wherein said radiation loops transmit and receive radiation.

27. (Original) The loop antenna of claim 1 wherein said radiation loops transmit and receive in the US PCS band operating from 1850 MHz to 1990 MHz.

28. (Original) The loop antenna of claim 1 wherein said radiation loops transmit and receive in a European DCS band operating from 1710 MHz to 1880 MHz.

29. (Original) The loop antenna of claim 1 wherein said radiation loops transmit and receive in a European GSM band operating from 880 MHz to 960 MHz.

30. (Original) The loop antenna of claim 1 wherein said radiation loops transmit and receive in b a US cellular band operating from 829 MHz to 896 MHz.

31. (Original) The loop antenna of claim 1 wherein said radiation loops transmit and receive in mobile telephone frequency bands anywhere from 800 MHz to 2500 MHz.

32. (Original) The loop antenna of claim 1 wherein a first one of said radiation loops is nested within a second one of said radiation loops and wherein said first one and said second one of said radiation loops are different in lengths by amounts that establish radiation frequencies that partially overlap and produce combined radiation to establish a combined bandwidth greater than a bandwidth for either said first one and said second one of said radiation loops alone.

33. (Original) The loop antenna of claim 1 wherein one or more first ones of said radiation loops and one or more said second ones of said radiation loops are different in lengths by amounts that establish radiation frequencies that do not substantially overlap and thereby produce combined radiation frequencies for said first ones and said second ones of said radiation loops to establish first and second bands of said frequencies that are separated and do not substantially overlap.

34. (Original) The loop antenna of claim 1 wherein one or more of said radiation loops is on one layer mounted on a dielectric material and one or more other ones of said radiation loops is on a different layer mounted on said dielectric material.

35. (Original) The loop antenna of claim 1 wherein a first one of said radiation loops is on one layer mounted on a dielectric material and where a conductive region is on a different layer mounted on said dielectric material juxtaposed said first one of said radiation loops.

36. (Original) The loop antenna of claim 1 wherein each of said loops have first and second termination points where said first termination points for each of said loops connect together in common at a first pad, where said second termination points for each of said loops connect together in common at a second pad and where said first and second pads connect all of said loops in said communication device.

37. (Original) The loop antenna of claim 36 wherein said loops provide multi-band performance.

38. (Original) The loop antenna of claim 1 wherein said bands of frequencies are not harmonically related.

39. (Original) The loop antenna of claim 1 formed of multiple layers and includes a parasitic patch on one layer juxtaposed an area of one of said loops on another layer to tune the antenna.

40. (Original) The loop antenna of claim 1 formed of multiple layers and a plurality of parasitic patches, each of said patches on one of said layers juxtaposed an area of one of said loops on another of said layers to tune the antenna.

41. (Original) The loop antenna of claim 39 wherein said plurality of parasitic patches are electrically connected.

42. (Original) The loop antenna of claim 34 wherein said plurality of parasitic patches are not electrically connected.

43. (Original) The loop antenna of claim 1 where said loops are nested to create a dual-band, band-pass antenna with good rejection between bands.

44. (Original) The loop antenna of claim 1 where said loops are nested to create a tri-band, band-pass antenna with good rejection between bands.

45. (Original) The loop antenna of claim 1 where said loops are nested to create a quad-band, band-pass antenna with good rejection between bands.

46. (Original) The loop antenna of claim 1 where said loops are located on any one of a plurality of layers.

47. (Original) The loop antenna of claim 1 where one or more of said loops are nested and connected to form a closed loop.

48. (Original) The loop antenna of claim 47 where one or more of said closed loops are floating.

49. (Original) The loop antenna of claim 47 wherein a first one of said closed loops is nested within a second one of said radiation loops and wherein said first one and said second one of said radiation loops are different in lengths by amounts that establish radiation frequencies that partially overlap and produce combined radiation frequencies to establish a combined bandwidth greater than a bandwidth for either said first one and said second one of said radiation loops alone.

50. (Original) The loop antenna of claim 1 wherein a first one of said radiation loops is nested within a second one of said radiation loops and wherein said first one and said second one of said radiation loops have a similar shape with an offset gap that establishes radiation frequencies that partially overlap and produce combined radiation frequencies to establish a combined bandwidth greater than a bandwidth for either said first one and said second one of said radiation loops alone.

51. (Original) The loop antenna of claim 1 wherein a first one of said radiation loops is nested within a second one of said radiation loops and wherein said first one and said second one of said radiation loops have dissimilar shapes that establishes multiband radiation frequencies and produce combined radiation frequencies for said first one and said second one of said radiation loops to establish multiband operation.

52. (Original) The loop antenna of claim 1 where said loops are formed with two or more legs.

53. (Original) The loop antenna of claim 52 where said legs are arrayed with a periodically repeating pattern.

54. (Original) The loop antenna of claim 52 wherein each of said legs includes a plurality of straight segments arrayed in a plurality of different directions.

55. (Original) The loop antenna of claim 1 wherein said loops are formed of an irregular pattern of segments arrayed with non-repeating perturbations.

56. (Original) The loop antenna of claim 1 wherein said loops are formed of an irregular pattern of segments arrayed with repeating perturbations.

57. (Original) The loop antenna of claim 1 wherein one or more of said loops includes a tuning element that tunes the antenna.

58. (Original) The loop antenna of claim 57 wherein said tuning element is adjusted in length to adjust a length of a loop without substantially altering antenna shape.

59. (Original) The loop antenna of claim 57 wherein said tuning element has a rectangular wave shape.

60. (Original) The loop antenna of claim 57 wherein said tuning element has a sinusoidal wave shape.

61. (Original) The loop antenna of claim 57 wherein said tuning element has an irregular shape.

62. (Original) The loop antenna of claim 57 wherein said tuning element is a linear element arrayed internal to a loop.

63. (Original) The loop antenna of claim 57 wherein said tuning element is a linear element arrayed external to a loop.

64. (Original) The loop antenna of claim 63 wherein said linear element adds a resonant frequency to said loop antenna.

65. (Original) The loop antenna of claim 1 wherein said antenna operates in one or more of the bands including an HF band from 3 to 30 MHz, a VHF band from 30 to 300 MHz, a UHF band from 300 MHz to 3 GHz, a SHF band from 3 to 30 GHz and an EHF band from 30 to 300 GHz band.

66. (Original) The loop antenna of claim 1 wherein said antenna operates in the any combination of bands from a group of bands including an HF band from 3 to 30 MHz, a VHF band from 30 to 300 MHz, a UHF band from 300 MHz to 3 GHz, a SHF band from 3 to 30 GHz and an EHF band from 30 to 300 GHz band.

67. (Original) The loop antenna of claim 1 wherein said antenna operates in the any combination of bands from a group of bands in the range from 3 MHz to 300 Ghz.

68. (Original) The loop antenna of claim 1 where said loops include two or more loops where each of said loops is a six-legged compressed loop antenna with one or more sublegs on each of said legs.

69. (Original) The loop antenna of claim 68 where each leg includes six sublegs.

70. (Original) The loop antenna of claim 1 where said loops include two or more loops where each of said loops is a multi-legged compressed loop antenna with from one to six sublegs on each leg.

71. (Original) The loop antenna of claim 1 wherein said loops are nested on the same layer where an area enclosed by a first one of said loops is within an area enclosed by a second one of said loops and where one or more loop interconnects connect between said first one of said loops and said second one of said loops to improve the VSWR or return loss of the antenna.

72. (Original) The loop antenna of claim 1 wherein said loops are nested on the same layer where an area enclosed by a first one of said loops is within an area enclosed by a second one of said loops and where one or more loop interconnects connect between said first one of said loops and said second one of said loops to improve the far field gain performance of the antenna.

73. (Original) The loop antenna of claim 1 wherein said loops are nested where an area enclosed by a first one of said loops is juxtaposed an area enclosed by a second one of said loops and where only one of said loops is physically connected to the circuit board and all other of said loops are not physically connected to said one of said loops.

74. (Original) The loop antenna of claim 1 where some of said nested loops are connected at the a drive point to form drive loops and other of said loops are unconnected loops not physically connected to the drive loops and wherein said unconnected loops are floating.

75. (Original) The loop antenna of claim 74 where said unconnected loops are open.

76. (Original) The loop antenna of claim 74 where said unconnected loops are closed.

77. (Original) The loop antenna of claim 1 formed of multiple layers and one or more parasitic patches, each of said patches on one of said layers juxtaposed an area of one of said loops on another of said layers to tune the antenna.

78. (Original) The loop antenna of claim 77 where one or more of said patches is connected to one or more of the antenna loops.

79. (Original) The loop antenna of claim 1 where an outer loop is driven on one side of a substrate and an inner loop is nested in said outer loop and where said inner loop is driven separately than the outer loop.

80. (Original) The loop antenna of claim 1 where an outer loop is driven on one side of a substrate and an inner loop is nested in said outer loop on the opposite side of said substrate.

81. (Original) The loop antenna of claim 1 where each of said loops is driven individually at a different frequency band of operation.

82. (Original) The loop antenna of claim 1 where the antenna operates in cellular frequencies of North America, South America, Europe, Asia or Australia.

83. (Original) The loop antenna of claim 1 where the antenna operates in cellular frequencies of North America, South America, Europe, Asia or Australia that are used for mobile telephones.

84. (Original) The loop antenna of claim 1 where the antenna is embedded in a communication device and operates in the cellular frequencies of North America, South America, Europe, Asia or Australia.

85. (Original) The loop antenna of claim 1 where the antenna operates in a PDA in any PDA frequency of the North America, South America, Europe, Asia or Australia.

86. (Original) The loop antenna of claim 1 wherein said communication device is a portable computer.

87. (Original) The loop antenna of claim 1 where the loops of said antenna are arrayed to have spatial diversity.

88. (Original) The loop antenna of claim 1 where the loops of said antenna are arrayed to have polarization diversity.

89. (Original) The loop antenna of claim 1 where the loops of said antenna are arrayed to have time diversity.

90. (Original) The loop antenna of claim 1 where the loops of said antenna are arrayed to have frequency diversity.

91. (Original) The loop antenna of claim 1 wherein said communication device operates for telemetry.

92. (Original) The loop antenna of claim 1 where a filter network is etched into the antenna to achieve a high Q.

93. (Original) The loop antenna of claim 1 where a filter network is etched into the antenna to achieve a high Q in one of the bands of the antenna.

94. (Original) The loop antenna of claim 1 wherein said loops are arrayed with an area enclosed by one of said loops overlapping an area enclosed by another of said loops to establish said antenna with low SAR.

95. (Original) The loop antenna of claim 1 wherein first ones of said loops have first pads on one layer and second ones of said loops have second pads on another layer where said first pads and said second pads are juxtaposed for coupling between layers.

96. (Original) The loop antenna of claim 1 wherein a first layer supports one or more first pads and a second layer supports one or more second pads connected to a loop where said first pads and said second pads are juxtaposed for coupling between layers.

97. (Original) The loop antenna of claim 1 wherein a first pad on a first layer capacitive couples a second pad on a second layer where said first and second pads are connected to loops to form a filter.

98. (Original) The loop antenna of claim 1 wherein said filter is a high-pass filter.

99. (Original) The loop antenna of claim 1 wherein a first layer on one side of a dielectric base supports one or more first loops and a second layer supports one or more second loops and including vias through said base for connecting said loops.

100. (Original) The loop antenna of claim 1 wherein a first layer on one side of a dielectric base supports a first loop and a second layer supports a second loop and including vias through said base for connecting said first loop and said second loop in a two turn antenna.

101. (Original) The loop antenna of claim 1 wherein one or more of said loops includes one or more segments that tunes the antenna.

102. (Original) The loop antenna of claim 101 wherein said one or more segments have different widths than other segments.

103. (Original) The loop antenna of claim 101 wherein at least one of said segments has a tapered width.

104. (Original) A communication device operating for exchanging energy in bands of radiation frequencies, comprising,

a case for housing the communication device,

a circuit board internal to said case for supporting electrical components including a transceiver unit,

a loop antenna formed of two or more radiation loops wherein,

each loop includes a plurality of electrically conducting segments, each segment having a segment length, where the segments are electrically connected in series to said connection means to form a loop antenna for exchange of energy in one of said bands of radiation frequencies and where said segments are arrayed in a compressed pattern,

said loops are superimposed whereby an area enclosed by one of said loops covers an area enclosed by another of said loops,

connection means for conduction of electrical current between said transceiver unit and said loop antenna.

105. (Original) The communication device of claim 104 wherein said loop antenna and said connection means are internal to said case.

106. (Original) The communication device of claim 104 wherein said loop antenna is affixed to the inside of the case by a pressure sensitive adhesive.

107. (Original) The communication device of claim 104 wherein said loop antenna is injection molded into the case.

108. (Original) The communication device of claim 104 wherein said loop antenna is insert molded into the case.

109. (Original) The communication device of claim 104 where the antenna is connected to the circuit board by a transmission line that is part of the antenna.

110. (Original) The loop antenna of claim 109 where the transmission line alone is not 50 ohms.

111. (Original) The communication device of claim 104 where the antenna is connected to the circuit board through a tang connector.

112. (Original) The communication device of claim 104 where the tang connector alone is not 50 ohms.

113. (Original) The communication device of claim 112 where the tang connector is 50 ohms.

114. (Original) The communication device of claim 113 where the antenna is connected to the circuit board through having a tang where the output impedance of the connector and the tang together is 50 ohms.

115. (Original) The communication device of claim 104 where the antenna is connected to the circuit board through a transmission line and a tang connector where the combined impedance of the transmissions line and tang connector is 50 ohms.

116. (Original) The communication device of claim 104 where the antenna is connected to the circuit board through a transmissions line that is part of the antenna where the antenna and transmission line together have an impedance of 50 ohms.

117. (Original) The communication device of claim 104 where the antenna is connected to the circuit board through a transmission line that is part of the antenna with an impedance that is not 50 ohms.

118. (Original) The communication device of claim 104 where the antenna is connected to the circuit board through a transmission line that is part of the antenna with an impedance that is 50 ohms.

119. (Original) The communication device of claim 104 wherein said loops are nested on the same layer where an area enclosed by a first one of said loops is within an area enclosed by a second one of said loops and where each of said loops has an independent connection to the circuit board.

120. (Original) The communication device of claim 104 wherein each of one or more of said loops provide operation in different frequency bands and where at least one of said loops for a different frequency band has an independent connection to the circuit board.

121. (Original) The communication device of claim 104 wherein said loops are nested where an area enclosed by a first one of said loops is juxtaposed an area enclosed by a second one of said loops and where one of said loops is physically connected to the circuit board and other of said loops are not physically connected to said one of said loops.

122. (Original) The communication device of claim 104 wherein said loops are nested where an area enclosed by a first one of said loops is juxtaposed an area enclosed by a second one of said loops and where only one loop is a drive loop connected at a drive point and all other loops are not physically connected to the drive loop and wherein said unconnected loops are open loops.

123. (Original) The communication device of claim 104 wherein said loops are nested where an area enclosed by a first one of said loops is juxtaposed an area enclosed by a second one of said loops and where only one loop is a drive loop connected at a drive point and all other loops are unconnected loops not physically connected to the drive loop and wherein said unconnected loops are open loops.

124. (Original) The communication device of claim 104 wherein said loops are nested where an area enclosed by a first one of said loops is juxtaposed an area enclosed by a second one of said loops and where only one loop is a drive loop connected at a drive point and all other loops are unconnected loops not physically connected to the drive loop and wherein said unconnected loops are closed loops.

125. (Original) The communication device of claim 104 wherein said loops are nested where an area enclosed by a first one of said loops is juxtaposed an area enclosed by a second one of said loops and where only one loop is a drive loop connected at a drive point and all other loops are unconnected loops not physically connected to the drive loop and wherein said unconnected loops are floating.

126. (Original) The communication device of claim 104 wherein said loops are nested where an area enclosed by a first one of said loops is juxtaposed an area enclosed by a second one of said loops and where only one loop is a drive loop connected at a drive point and all other loops are unconnected loops not physically connected to the drive loop and wherein said unconnected loops are connected to ground.

127. (Original) The communication device of claim 104 wherein said circuit board includes a ground plane and where said loop antenna is in an antenna plane substantially parallel to said ground plane.

128. (Original) The communication device of claim 127 wherein said antenna plane has an offset from said circuit board.

129. (Original) The communication device of claim 128 wherein said offset is less than 10 mm.

130. (Original) The communication device of claim 104 wherein said loops are nested on the same layer where an area enclosed by a first one of said loops is within an area enclosed by a second one of said loops and including first and second connecting pads, each of said pads connected to both said first one and said second one of said loops.

131. (Original) The communication device of claim 130 including a filter connected between said first and second pads.

132. (Original) The communication device of claim 131 wherein said filter is a conductive segment having dimensions establishing a high-pass filter.

133. (Original) A method of making a loop antenna, for use with a communication device operating for exchanging energy in bands of radiation frequencies, comprising the steps of,

forming two or more radiation loops having a tuning parameter on a dielectric substrate to make an instantiation of said loop antenna wherein,

at least one of said loops is arrayed in a compressed pattern,

said loops are superimposed whereby an area enclosed by one of said loops covers an area enclosed by another of said loops;

testing said instantiation of said loop antenna to determine properties of the instantiation of the loop antenna;

modifying said tuning parameter;

repeating said forming, testing and modifying steps until the properties of the loop antenna are acceptable.

134. (Original) The method of claim 133 wherein said tuning parameter is the length of a tuning section connected in series with a loop.

135. (Original) The method of claim 133 wherein said tuning parameter is a gap between loops.

136. (Original) The method of claim 133 wherein said tuning parameter is a width of one or more segments.

137. (Original) The method of claim 136 wherein at least one of said one or more segments is tapered.

138. (Original) The method of claim 133 wherein said tuning parameter is a length of a stub situated internal to a loop.

139. (Original) The method of claim 133 wherein said tuning parameter is a length of a stub situated external to a loop.

140. (Original) The method of claim 133 wherein said tuning parameter is a relative location of juxtaposed loops.

141. (Original) The method of claim 133 wherein said tuning parameter is a length of one or more of said loops.

142. (Original) The method of claim 133 wherein said steps include the step of simulating performance of said antenna.

143. (Original) The method of claim 142 wherein said step of simulating said antenna is repeated after one or more of said modifying steps.

144. (Original) A loop antenna, for use with a communication device, operating for exchanging energy in bands of radiation frequencies, comprising,

connection means for conduction of electrical current,

two or more radiation loops wherein,

each loop includes a plurality of electrically conducting segments, each segment having a segment length, where the segments are electrically connected in series to said connection means to form a loop antenna for exchange of energy in one of said bands of radiation frequencies and where said segments are arrayed in a compressed pattern,

said loops are superimposed whereby an area enclosed by one of said loops covers an area enclosed by another of said loops,

a tuning element for tuning said loop antenna.