WO2001039321A1 - Capacitively loaded antenna and an antenna assembly - Google Patents

Capacitively loaded antenna and an antenna assembly Download PDF

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Publication number
WO2001039321A1
WO2001039321A1 PCT/SE2000/002333 SE0002333W WO0139321A1 WO 2001039321 A1 WO2001039321 A1 WO 2001039321A1 SE 0002333 W SE0002333 W SE 0002333W WO 0139321 A1 WO0139321 A1 WO 0139321A1
Authority
WO
WIPO (PCT)
Prior art keywords
antenna
capacitive load
ground
radiating element
antenna according
Prior art date
Application number
PCT/SE2000/002333
Other languages
French (fr)
Inventor
Roger Gustafs
Original Assignee
Smarteq Wireless Ab
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Smarteq Wireless Ab filed Critical Smarteq Wireless Ab
Priority to AU17498/01A priority Critical patent/AU1749801A/en
Publication of WO2001039321A1 publication Critical patent/WO2001039321A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/28—Combinations of substantially independent non-interacting antenna units or systems
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/28—Adaptation for use in or on aircraft, missiles, satellites, or balloons
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/28—Adaptation for use in or on aircraft, missiles, satellites, or balloons
    • H01Q1/282—Modifying the aerodynamic properties of the vehicle, e.g. projecting type aerials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/32—Adaptation for use in or on road or rail vehicles
    • H01Q1/325—Adaptation for use in or on road or rail vehicles characterised by the location of the antenna on the vehicle
    • H01Q1/3275—Adaptation for use in or on road or rail vehicles characterised by the location of the antenna on the vehicle mounted on a horizontal surface of the vehicle, e.g. on roof, hood, trunk
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
    • H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
    • H01Q9/32—Vertical arrangement of element
    • H01Q9/36—Vertical arrangement of element with top loading

Definitions

  • the present invention relates to a capacitively loaded antenna, and in particular to a capacitively loaded meander antenna, according to the preamble of claim 1.
  • the invention also relates to an antenna assembly.
  • a general method for optimising an electrically small antenna for common applications is maximising the product of bandwidth and radiation efficiency for the antenna. Occasionally this can be done by decreasing the reactance of the antenna without decreasing, and preferably by increasing, the radiation efficiency. Decreasing the reactance of a monopole antenna can be done by minimising the inductive loading or maximising the capacitive loading. An added capacitive load will optimally reduce the necessary inductive loading for an electrically small self resonant monopole, will give no added losses, and will increase the total currents on the monopole. Together this means that capacitive loading will increase the above mentioned product of bandwidth and radiation efficiency.
  • Adding a load, capacitive or inductive, at the top is optimum for radiation efficiency, though other mechanical or matching aspects might exclude such top loading.
  • a self resonant electrically small capacitively loaded antenna will still need a minimum amount of inductive loading.
  • the present invention seeks to provide an antenna that optimise the use of an electrically small cubic volume available for the antenna, in particular with respect to radiation efficiency and bandwidth.
  • the invention is also directed to an antenna assembly including a capacitively loaded antenna.
  • An advantage with the present invention is that a simple construction is obtained thus reducing manufacturing costs.
  • the antenna may be assembled of flat parts, which are easy to produce and store.
  • the antenna may be made very robust only by adding one support.
  • a further advantage is that no lumped electric component needs to be added for matching the capacitively top loaded antenna, which is an expensive process in manufacturing.
  • Fig. 1 shows a preferred embodiment of the present invention.
  • Fig. 2 shows a principal function of the antenna in Fig. 1.
  • Fig. 3 shows a second preferred embodiment of the present invention.
  • Fig. 4 shows a principal function of the antenna in Fig. 3.
  • Fig. 5 shows an antenna assembly including an antenna according to the present invention.
  • Fig. 1 shows a preferred embodiment of an antenna 10 according to the present invention.
  • the antenna comprises a vertical radiating element 1, having a meandering shape, a top plate 2, referred to as a capacitive load, and a ground plane means 3- 5.
  • the ground plane comprises a first ground member 3 arranged in a first plane and a second and a third ground member 4, 5 arranged in a second plane.
  • the first ground member has an essentially E-shape and is provided with a grounding point 11 preferably symmetrically arranged.
  • a central portion 12 of the E-shape is connected to a first end 13 of the vertical radiating element 1 via a matching means 6.
  • the first ground member further provides two essentially identical mirror-inverted branches each having a distal point 14, 15.
  • the first ground member 3 is connected to said second 4 ground member at said distal point 14 and said third 5 ground member at said distal point 15, respectively.
  • the total length from said grounding point 11 to a free end 16 of said second and third ground member, respectively, via said distal point 14, 15, is set to ⁇ /4, a quarter of a wavelength at the frequency of operation for the antenna 10.
  • a feeding point 17 is provided at said first end of the vertical radiating element 1.
  • a second end 18 of said radiating element 1 is connected to said capacitive load 2.
  • the capacitive load 2 has a first side 7 and a second side 8, where said second side 8 is facing the ground means 3-5 and the first side 7 is facing away from the ground means 3-5.
  • the second end 18 of the vertical radiating element 1 is connected to the first side 7 of the capacitive load 2 to allow for a more robust and less compressed meander pattern.
  • the vertical radiating element 1 and the capacitive load 2 can preferably be made of a solid metal sheet or a partially coated substrate (e.g. a printed circuit board).
  • the ground plane means preferably comprises a substrate, such as a printed circuit board, on which said first ground member 3 is arranged on a first side and said second and third ground member 4, 5 are arranged on a second side.
  • the first ground member 3 is connected, at the distal end 14, to the second ground member 4, at an end opposite to said free end 16 through said substrate.
  • the first and third ground members are connected is a similar way.
  • the matching means 6 is preferably a printed part of the printed circuit board.
  • Fig. 2 shows a principal function of the antenna 10 in Fig. 1.
  • a coaxial cable 20 is shown in the figure to indicate how to connect a radio communication apparatus (not shown) to the antenna 10.
  • a signal connector 21 is connected to the feeding point 17 and a ground connector 22 is connected to the grounding point 11.
  • the matching means 6 is illustrated by an inductor between said feeding point 17 and said grounding point 11.
  • the meandering patterned vertical radiating element 1 is illustrated by a meandering line between the feeding point 17 and the capacitive load 2, which is illustrated by a strait line.
  • the ground plane means comprises the first ground member 3, illustrated by a line, and the second and third ground member 4, 5 are illustrated by separate lines.
  • the first ground member 3 may be arranged on top of the second 4 and the third 5 ground members as shown in figure 1, but it is also possible to arrange the second and third ground members on top of the first ground member 3.
  • the ground members 3-5 and the capacitive load are preferable arranged in parallel.
  • the total height of the antenna 10 is approximately ⁇ /16, a sixteenths of the wavelength at the frequency of operation for the antenna.
  • Fig. 3 shows an second embodiment of an antenna 30.
  • the antenna comprises the same elements as the antenna described in connection with Fig. 1, but the ground plane means has an alternative shaping.
  • the same elements are denoted with the same reference numerals as in Fig. 2.
  • the ground plane means comprises a first member 30 having an open circular shape, where the matching means 6 is connected to a connection at a first end 31 of the first ground member 30 and a second end 32 of the first ground member 30 is provided with a connection 33 to a second ground member 40.
  • the second ground member is a flat surface having substantially the same outer dimensions as the first ground member 30.
  • the connection 33 from the first to the second ground member is located essentially at the centre of the second ground member 40.
  • the grounding point 11 and the feeding point 17 are located at the same place as in Fig. 1.
  • Fig. 4 shows the principal function of the antenna in Fig. 3.
  • the alternative shape of the ground means is illustrated by a meandering line from the grounding portion 11, corresponding to the first ground member 30, down to a centre portion of a straight line, corresponding to the second ground member 40.
  • Fig. 5 shows an antenna assembly 50, especially adapted for mounting on a vehicle body, e.g. on the roof of a car.
  • a GPS antenna 52 is also provided and mounted on the base 51.
  • An coaxial antenna cable 54 comprising a ground connector and a signal connector, is arranged to be connected to the grounding point and the feeding point, respectively, of the antenna 10.
  • the assembly 50 is covered and protective by a housing 55.
  • a dielectric support 56 is mounted on the base 51 and is attached at its upper end to the top load 2.
  • the top load 2 will be steadily fixed and will also serve to support the radiating element 1.
  • Such a support or similar could advantageously also be used in the previous embodiments.

Abstract

The present invention relates to an electrically small capacitively loaded antenna comprising ground plane means including a grounding portion, said grounding portion being connectable to a ground connection, at least one radiating element, having a first end and a second end, including a feeding portion at said first end, said feeding portion being connectable to a signal connection, and a capacitive load being connected to said second end of said radiating element, said radiating element has a meandering shape, said ground plane means is arranged in at least two planes which are interconnected, and said antenna further comprises a matching means arranged between said first end of the radiating element and said ground plane means. The invention also relates to an antenna assembly including a capacitively loaded antenna.

Description

Capacitively loaded antenna and an antenna assembly
Technical field
The present invention relates to a capacitively loaded antenna, and in particular to a capacitively loaded meander antenna, according to the preamble of claim 1. The invention also relates to an antenna assembly.
Prior art
A general method for optimising an electrically small antenna for common applications is maximising the product of bandwidth and radiation efficiency for the antenna. Occasionally this can be done by decreasing the reactance of the antenna without decreasing, and preferably by increasing, the radiation efficiency. Decreasing the reactance of a monopole antenna can be done by minimising the inductive loading or maximising the capacitive loading. An added capacitive load will optimally reduce the necessary inductive loading for an electrically small self resonant monopole, will give no added losses, and will increase the total currents on the monopole. Together this means that capacitive loading will increase the above mentioned product of bandwidth and radiation efficiency.
Adding a load, capacitive or inductive, at the top is optimum for radiation efficiency, though other mechanical or matching aspects might exclude such top loading. A self resonant electrically small capacitively loaded antenna will still need a minimum amount of inductive loading.
Attempts to optimise the use of an available electrically small cubic volume for an antenna by introducing a top plate and a small coil, in said antenna, can be a mechanical and economical challenge, attempts have been made to take care of this and allow for easy mass production of a robust antenna. Summary of the invention
The present invention seeks to provide an antenna that optimise the use of an electrically small cubic volume available for the antenna, in particular with respect to radiation efficiency and bandwidth.
According to an aspect of the invention, there is provided a capacitively loaded antenna as specified in claim 1.
Further aspects of the invention is included in the dependent claims .
The invention is also directed to an antenna assembly including a capacitively loaded antenna.
An advantage with the present invention is that a simple construction is obtained thus reducing manufacturing costs.
Another advantage of the present invention is that the antenna may be assembled of flat parts, which are easy to produce and store.
Another advantage is that the antenna may be made very robust only by adding one support.
A further advantage is that no lumped electric component needs to be added for matching the capacitively top loaded antenna, which is an expensive process in manufacturing.
Brief description of the drawings
Fig. 1 shows a preferred embodiment of the present invention.
Fig. 2 shows a principal function of the antenna in Fig. 1.
Fig. 3 shows a second preferred embodiment of the present invention. Fig. 4 shows a principal function of the antenna in Fig. 3.
Fig. 5 shows an antenna assembly including an antenna according to the present invention.
Detailed description of the preferred embodiment
Fig. 1 shows a preferred embodiment of an antenna 10 according to the present invention. The antenna comprises a vertical radiating element 1, having a meandering shape, a top plate 2, referred to as a capacitive load, and a ground plane means 3- 5. The ground plane comprises a first ground member 3 arranged in a first plane and a second and a third ground member 4, 5 arranged in a second plane.
The first ground member has an essentially E-shape and is provided with a grounding point 11 preferably symmetrically arranged. A central portion 12 of the E-shape is connected to a first end 13 of the vertical radiating element 1 via a matching means 6. The first ground member further provides two essentially identical mirror-inverted branches each having a distal point 14, 15.
The first ground member 3 is connected to said second 4 ground member at said distal point 14 and said third 5 ground member at said distal point 15, respectively. The total length from said grounding point 11 to a free end 16 of said second and third ground member, respectively, via said distal point 14, 15, is set to λ/4, a quarter of a wavelength at the frequency of operation for the antenna 10.
A feeding point 17 is provided at said first end of the vertical radiating element 1. A second end 18 of said radiating element 1 is connected to said capacitive load 2. The capacitive load 2 has a first side 7 and a second side 8, where said second side 8 is facing the ground means 3-5 and the first side 7 is facing away from the ground means 3-5. The second end 18 of the vertical radiating element 1 is connected to the first side 7 of the capacitive load 2 to allow for a more robust and less compressed meander pattern.
The vertical radiating element 1 and the capacitive load 2 can preferably be made of a solid metal sheet or a partially coated substrate (e.g. a printed circuit board).
The ground plane means preferably comprises a substrate, such as a printed circuit board, on which said first ground member 3 is arranged on a first side and said second and third ground member 4, 5 are arranged on a second side. The first ground member 3 is connected, at the distal end 14, to the second ground member 4, at an end opposite to said free end 16 through said substrate. The first and third ground members are connected is a similar way. The matching means 6 is preferably a printed part of the printed circuit board.
Fig. 2 shows a principal function of the antenna 10 in Fig. 1. A coaxial cable 20 is shown in the figure to indicate how to connect a radio communication apparatus (not shown) to the antenna 10. A signal connector 21 is connected to the feeding point 17 and a ground connector 22 is connected to the grounding point 11. The matching means 6 is illustrated by an inductor between said feeding point 17 and said grounding point 11. The meandering patterned vertical radiating element 1 is illustrated by a meandering line between the feeding point 17 and the capacitive load 2, which is illustrated by a strait line. The ground plane means comprises the first ground member 3, illustrated by a line, and the second and third ground member 4, 5 are illustrated by separate lines. The first ground member 3 may be arranged on top of the second 4 and the third 5 ground members as shown in figure 1, but it is also possible to arrange the second and third ground members on top of the first ground member 3.
The ground members 3-5 and the capacitive load are preferable arranged in parallel. The total height of the antenna 10 is approximately λ/16, a sixteenths of the wavelength at the frequency of operation for the antenna.
Fig. 3 shows an second embodiment of an antenna 30. The antenna comprises the same elements as the antenna described in connection with Fig. 1, but the ground plane means has an alternative shaping. The same elements are denoted with the same reference numerals as in Fig. 2. The ground plane means comprises a first member 30 having an open circular shape, where the matching means 6 is connected to a connection at a first end 31 of the first ground member 30 and a second end 32 of the first ground member 30 is provided with a connection 33 to a second ground member 40. The second ground member is a flat surface having substantially the same outer dimensions as the first ground member 30. The connection 33 from the first to the second ground member is located essentially at the centre of the second ground member 40. The grounding point 11 and the feeding point 17 are located at the same place as in Fig. 1.
Fig. 4 shows the principal function of the antenna in Fig. 3. The alternative shape of the ground means is illustrated by a meandering line from the grounding portion 11, corresponding to the first ground member 30, down to a centre portion of a straight line, corresponding to the second ground member 40.
Fig. 5 shows an antenna assembly 50, especially adapted for mounting on a vehicle body, e.g. on the roof of a car. The antenna 10, .which include the radiation element 1, the top load 2 and the ground plane means 3-5, is mounted on a base 51. A GPS antenna 52 is also provided and mounted on the base 51. In the centre portion of the base 51 is a hole 53 arranged for feeding through cables. An coaxial antenna cable 54, comprising a ground connector and a signal connector, is arranged to be connected to the grounding point and the feeding point, respectively, of the antenna 10. The assembly 50 is covered and protective by a housing 55.
A dielectric support 56 is mounted on the base 51 and is attached at its upper end to the top load 2. Hereby the top load 2 will be steadily fixed and will also serve to support the radiating element 1. Such a support or similar could advantageously also be used in the previous embodiments.

Claims

Claims
1. A capacitively loaded antenna comprising:
ground plane means including a grounding portion, said grounding portion being connectable to a ground connection,
- at least one radiating element, having a first end and a second end, including a feeding portion at said first end, said feeding portion being connectable to a signal connection, and
a capacitive load being connected to said second end of said radiating element
characterised in that
said radiating element has a meandering shape,
said ground plane means is arranged in at least two planes which are interconnected, and
- said antenna further comprises a matching means arranged between said first end of the radiating element and said ground plane means.
2. The antenna according to claim 1, wherein said capacitive load has a first surface and a second surface, where the second end of said radiating element is connected to said first surface of the capacitive load, and said second surface of said capacitive load face said ground plane means.
3. The antenna according to claim 1, wherein said capacitive load has a first surface and a second surface, where the second end of said radiating element is connected to said second surface of the capacitive load, and said second surface of said capacitive load face said ground plane means.
4. The antenna according to any of claims 1-3, wherein said at least two interconnected ground planes are arranged on opposite surfaces of a substrate.
5. The antenna according to any of claims 1-4, wherein said capacitive load is a metal member.
6. The antenna according to any of claims 1-5, wherein said radiating element is a metal member.
7. The antenna according to claim 5 or 6, wherein said metal member is arranged on a substrate.
8. The antenna according to any of claims 1-7, wherein said grounding portion is arranged on a first ground member arranged in a first plane, said first ground member having an E-shape, where said grounding portion is essentially centred thereby creating two essentially identical mirror-inverted branches and one centre portion where said matching means is connected.
9. The antenna according to claim 8, wherein said first ground member is interconnected with a second and third ground member arranged in a second plane at a distal point of each of said branches, respectively, each second and third ground member having a free end.
10. The antenna according to any of claims 8 or 9, wherein said first plane is arranged between said second plane and said capacitive load, essentially in parallel.
11. The antenna according to any of claims 8 or 9, wherein said second plane is arranged between said first plane and said capacitive load, essentially in parallel.
12. The antenna according to any of claims 8-11, wherein the total length from the grounding portion to each free end is a quarter of a wavelength.
13. The antenna according to any of the proceeding claims, wherein said capacitive load is supported by a support, and said radiating element is supported by the capacitive load.
14. An antenna assembly, characterised in that said antenna assembly comprises a capacitive loaded antenna according to any of claims 1-13, said antenna assembly being arranged to be mounted on a vehicle.
15. The antenna assembly according to claim 14, wherein said antenna assembly further comprises a GPS antenna.
PCT/SE2000/002333 1999-11-29 2000-11-27 Capacitively loaded antenna and an antenna assembly WO2001039321A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU17498/01A AU1749801A (en) 1999-11-29 2000-11-27 Capacitively loaded antenna and an antenna assembly

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9904320-0 1999-11-29
SE9904320A SE515504C2 (en) 1999-11-29 1999-11-29 Capacitively loaded antenna and an antenna unit

Publications (1)

Publication Number Publication Date
WO2001039321A1 true WO2001039321A1 (en) 2001-05-31

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AU (1) AU1749801A (en)
SE (1) SE515504C2 (en)
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Cited By (14)

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WO2002065582A1 (en) * 2001-02-13 2002-08-22 Koninklijke Philips Electronics N.V. Wireless terminal
WO2003098735A1 (en) * 2002-05-16 2003-11-27 Kathrein-Werke Kg Roof for motor vehicles
DE20311035U1 (en) * 2003-07-17 2004-04-08 Kathrein-Werke Kg Antenna arrangement, in particular for motor vehicles
EP1411585A1 (en) * 2002-10-15 2004-04-21 Calearo S.r.l. Cover for vehicular antennas
EP1432071A2 (en) * 2002-12-16 2004-06-23 Alps Electric Co., Ltd. Compact and low-profile antenna device having wide range of resonance frequencies
EP1437795A1 (en) * 2002-06-27 2004-07-14 Matsushita Electric Industrial Co., Ltd. Antenna device
EP1306924A3 (en) * 2001-10-24 2004-10-27 Alps Electric Co., Ltd. Monopole antenna that can easily be reduced in height dimension
EP1683231A1 (en) * 2003-10-30 2006-07-26 Wavetest Systems, Inc. High performance antenna
US7362283B2 (en) 2001-09-13 2008-04-22 Fractus, S.A. Multilevel and space-filling ground-planes for miniature and multiband antennas
EP1597794B1 (en) * 2003-02-19 2008-08-20 Fractus S.A. Miniature antenna having a volumetric structure
US7486242B2 (en) 2002-06-25 2009-02-03 Fractus, S.A. Multiband antenna for handheld terminal
US7928915B2 (en) 2004-09-21 2011-04-19 Fractus, S.A. Multilevel ground-plane for a mobile device
US8941541B2 (en) 1999-09-20 2015-01-27 Fractus, S.A. Multilevel antennae
JP2017108395A (en) * 2015-11-27 2017-06-15 原田工業株式会社 Low-profile antenna device

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US9761934B2 (en) 1999-09-20 2017-09-12 Fractus, S.A. Multilevel antennae
US9240632B2 (en) 1999-09-20 2016-01-19 Fractus, S.A. Multilevel antennae
US10056682B2 (en) 1999-09-20 2018-08-21 Fractus, S.A. Multilevel antennae
US9000985B2 (en) 1999-09-20 2015-04-07 Fractus, S.A. Multilevel antennae
US8976069B2 (en) 1999-09-20 2015-03-10 Fractus, S.A. Multilevel antennae
US9054421B2 (en) 1999-09-20 2015-06-09 Fractus, S.A. Multilevel antennae
US9362617B2 (en) 1999-09-20 2016-06-07 Fractus, S.A. Multilevel antennae
US8941541B2 (en) 1999-09-20 2015-01-27 Fractus, S.A. Multilevel antennae
WO2002065582A1 (en) * 2001-02-13 2002-08-22 Koninklijke Philips Electronics N.V. Wireless terminal
US7522936B2 (en) 2001-02-13 2009-04-21 Nxp B.V. Wireless terminal
US7688276B2 (en) 2001-09-13 2010-03-30 Fractus, S.A. Multilevel and space-filling ground-planes for miniature and multiband antennas
US7362283B2 (en) 2001-09-13 2008-04-22 Fractus, S.A. Multilevel and space-filling ground-planes for miniature and multiband antennas
US7911394B2 (en) 2001-09-13 2011-03-22 Fractus, S.A. Multilevel and space-filling ground-planes for miniature and multiband antennas
US8581785B2 (en) 2001-09-13 2013-11-12 Fractus, S.A. Multilevel and space-filling ground-planes for miniature and multiband antennas
EP1306924A3 (en) * 2001-10-24 2004-10-27 Alps Electric Co., Ltd. Monopole antenna that can easily be reduced in height dimension
WO2003098735A1 (en) * 2002-05-16 2003-11-27 Kathrein-Werke Kg Roof for motor vehicles
US7486242B2 (en) 2002-06-25 2009-02-03 Fractus, S.A. Multiband antenna for handheld terminal
US7903037B2 (en) 2002-06-25 2011-03-08 Fractus, S.A. Multiband antenna for handheld terminal
EP1437795A4 (en) * 2002-06-27 2008-12-10 Panasonic Corp Antenna device
EP1437795A1 (en) * 2002-06-27 2004-07-14 Matsushita Electric Industrial Co., Ltd. Antenna device
EP1411585A1 (en) * 2002-10-15 2004-04-21 Calearo S.r.l. Cover for vehicular antennas
EP1432071A3 (en) * 2002-12-16 2004-07-07 Alps Electric Co., Ltd. Compact and low-profile antenna device having wide range of resonance frequencies
EP1432071A2 (en) * 2002-12-16 2004-06-23 Alps Electric Co., Ltd. Compact and low-profile antenna device having wide range of resonance frequencies
US8593349B2 (en) 2003-02-19 2013-11-26 Fractus, S.A. Miniature antenna having a volumetric structure
US8149171B2 (en) 2003-02-19 2012-04-03 Fractus, S.A. Miniature antenna having a volumetric structure
US7504997B2 (en) 2003-02-19 2009-03-17 Fractus, S.A. Miniature antenna having a volumetric structure
EP1912280A3 (en) * 2003-02-19 2008-10-22 Fractus, S.A. Miniature antenna having a volumetric structure
EP1597794B1 (en) * 2003-02-19 2008-08-20 Fractus S.A. Miniature antenna having a volumetric structure
US7030821B2 (en) 2003-07-17 2006-04-18 Kathrein-Werke Kg Antenna arrangement for motor vehicles
DE20311035U1 (en) * 2003-07-17 2004-04-08 Kathrein-Werke Kg Antenna arrangement, in particular for motor vehicles
EP1683231A4 (en) * 2003-10-30 2008-01-23 Wavetest Systems Inc High performance antenna
EP1683231A1 (en) * 2003-10-30 2006-07-26 Wavetest Systems, Inc. High performance antenna
US7928915B2 (en) 2004-09-21 2011-04-19 Fractus, S.A. Multilevel ground-plane for a mobile device
JP2017108395A (en) * 2015-11-27 2017-06-15 原田工業株式会社 Low-profile antenna device

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AU1749801A (en) 2001-06-04
SE9904320D0 (en) 1999-11-29
SE515504C2 (en) 2001-08-20
SE9904320L (en) 2001-05-30

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