Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/48—Earthing means; Earth screens; Counterpoises
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/12—Supports; Mounting means
  • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
  • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
  • H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
  • H01Q1/242—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use
  • H01Q1/243—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use with built-in antennas
• • 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
  • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
  • H01Q9/0421—Substantially flat resonant element parallel to ground plane, e.g. patch antenna with a shorting wall or a shorting pin at one end of the element
• • 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
  • H01Q9/42—Resonant antennas with feed to end of elongated active element, e.g. unipole with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Definitions

• the invention lies in the field of antennas and relates more specifically to a method of manufacturing a planar antenna comprising at least one radiating source and at least one conductive plane associated with said radiating source.
• the invention also relates to a planar antenna comprising at least one radiating source and at least one conducting plane associated with said radiating source.
• the invention also relates to a transmitter / receiver comprising such a planar antenna.
• FIG. 1 schematically illustrates a planar antenna 1 comprising a source 2 coupled to a conductive plane 4 comprising n superimposed layers, the source 2 being adapted to generate, when powered, an electric field and a magnetic field radiated around the conductive plane 4.
• Antenna 1 may be for example an antenna printed on an electronic card, and in this case, the conductor plane 4 is the power plan of the electronic card. Due to the proximity of the antenna to the conductive plane 4, an induced current flow is generated on the surface of the different layers of the conductor plane 4 by the magnetic field radiated by the source 2. This current flow plays a role. important on the performance of the antenna.
• the surface of the conductive plane 4 has an influence on both the impedance, the bandwidth, the efficiency and the shape of the radiation pattern of the antenna. More particularly, it has been found that for an operating wavelength antenna ⁇ , an area of the conductive plane 4 greater than ( ⁇ 2 / (16) causes a deformation of the radiation pattern and the gain of the antenna in one or more directions of space. An example of such a malfunction will be described in the case of an IFA type antenna (for Inverted-F Antenna) diagrammatically shown in FIG. 2.
• the antenna illustrated in FIG. 2 has an operating frequency of 2.5 GHz, close to a rectangular conductor plane 4 of length 125 mm and width 50 mm.
• the 3D radiation diagram of this antenna is illustrated in FIG. 3.
• the radiation of the antenna 2 is essentially concentrated around the lower end of the conductive plane 4 with strong distortions. around the central part of this conductive plane.
• the maximum gain is 4.7 dB and is measured at the lower end of the conductor plane 4 while at the central portion of the conductive plane 4, the measured gain is less than -6 dB. This results in a loss of 10 dB between the lower end and the central part.
• Figures 4 and 5 are projections on a plane of Figure 3.
• FIG. 6, illustrating the adaptation curve of the antenna of FIG. 2 shows a low bandwidth at 143 MHz, ie of the order of 5% at 2.5 GHz.
• FIG. 7 schematically illustrates the distribution of the currents induced on the surface of the conductive plane 4 of the IFA antenna of FIG. 2. This FIG. 7 shows strong losses of the currents over the entire surface of this conductive plane 4. The current is distributed along the conductive plane 4 with a density of the order of -20 dB (A / m) relative to the maximum density.
• a solution of the prior art for reducing the influence of the conductive plane 4 on the performance of the antenna is to separate the radiating source 2 and the conductive plane 4 by a distance to limit their mutual interaction. This solution does not take into account the mechanical constraints and the congestion encountered in the manufacture of integrated planar antennas on a printed circuit.
• An object of the invention is to overcome the disadvantages of the prior art described above.
• This object is achieved by means of a method of manufacturing a planar antenna comprising at least one source radiating an electromagnetic field of wavelength ⁇ and at least one conducting plane associated with said source.
• the conductive plane is cut into a plurality of contiguous flat conductive surfaces so that the least the surface closest to the source has a shape and dimensions such that its area is between (k 2 / 16) and (3. ⁇ 2/8), and connects two conductor flat surfaces contiguous by a conductive blade having an area smaller than those of the conductive surfaces in order to reduce the induced leakage currents and the coupling between said planar surfaces .
• said flat conductive surfaces and said planar conductive blades have a polygonal shape.
• the flat conductive surfaces and the flat conductive blades have a rectangular shape.
• the flat conductive surfaces and the flat conductive blades have a square shape.
• planar conductive strips have a lower or area equal to ( ⁇ 2/100).
• FIG. 1 previously described, schematically illustrates a general architecture of a planar antenna of the prior art
• FIG. 2 previously described, schematically illustrates an antenna of the IFA (for Inverted-F Antenna) type of the prior art
• FIG. 3 and 4-5 previously described, respectively illustrate the 3D radiation pattern and the 2D polar radiation patterns of the antenna of FIG. 2,
• Figure 6 shows the adaptation curve of the antenna of Figure 2
• FIG. 7 schematically illustrates the distribution of the surface currents on the conductive plane of the antenna of FIG. 2
• FIG. 8 schematically illustrates a first example of an IFA-type antenna produced by the method according to the invention
• FIG. 9 is a 3D radiation diagram of the antenna of FIG. 8,
• Figures 10 and 11 show the 2D polar radiation pattern of the antenna of Figure 8.
• Figure 12 shows the adaptation curve of the antenna of Figure 8.
• FIG. 13 schematically illustrates the distribution of the surface currents on the conductive plane of the antenna of FIG. 8.
• FIG. 14 schematically illustrates a second example of a monopole type antenna produced by the method according to the invention.
• FIG. 8 diagrammatically shows a planar antenna 10 comprising a source 2 radiating an electromagnetic field of wavelength ⁇ , and a conductive plane 4, comprising n superimposed layers (not shown on FIG. this figure), associated with the source 2.
• the conductive plane 4 comprises three contiguous flat conductive surfaces 10, 11 and 12 each having a rectangular shape.
• the respective areas of conductor flat surfaces contiguous 10, 11 and 12 are between (k 2/16) and (3. ⁇ 2/8).
• Two adjacent flat conductive surfaces 6 are connected by a conductive strip 8, obtained by cutting each layer of the conductive plane 4, and having a smaller area than the conductive surfaces 10, 11 and 12.
• the antenna illustrated in FIG. 8 has an operating frequency of 2.5 GHz and comprises a rectangular conducting plane 4 of length 125 mm and width 50 mm.
• the 3D radiation diagram of this antenna is illustrated in FIG. 9, on which a radiation uniformly distributed around the central part of the conductive plane 4 can be seen.
• the maximum gain is 2 dB and is measured around the central part of the conductive plane 4, while the gain measured at both ends of the conductive plane 4, is 0 dB.
• Figures 10 and 11 are projections on a plane of Figure 9.
• FIG. 11 illustrating a projection on the xy plane, there are two main lobes respectively at + 170 ° with an opening of 123 ° (at -3 dB) and at 10 ° with an opening of 123 °.
• the maximum gain of the lobe is 0.8 dB.
• FIG. 12 illustrating the adaptation curve of the antenna of FIG. 8, it can be seen that the bandwidth has been significantly improved with respect to the antenna of FIG. 2 and is increased to 237 MHz, ie 10% at 2.5 GHz.
• FIG. 13 schematically illustrates the distribution of the density of the currents induced on the surface of the conductive plane 4 of the IFA antenna of FIG. 8.
• This density is maximum on the flat surface 10 closest to the source 2, reduced on the flat surface 11 central, and almost zero on the flat surface 12 farthest from the source.
• the source 2 is arranged on a ground plane 20 independent of the plane surfaces 10, 11, 12 and 13 cut on the conductive plane.
• the cutting of the conductive plane is carried out in the same way as for the antenna of FIG. 13 in which the source 2 is arranged directly on the first planar surface 10 of the conductive plane.
• the antennas of FIGS. 13 and 14 may comprise more than three contiguous planar conducting surfaces having any polygonal shape optimized for, on the one hand, allowing its installation on the printed circuit, and on the other hand, for maintaining their respective areas between (k 2/16) and (3. ⁇ 2/8).
• the planar conductive strip 8 may also be of any polygonal shape having an area smaller than ( ⁇ 2/100).
• the antennas according to the invention can be integrated in a transmitter / receiver, such as a remote control for example or in a mobile phone, a tablet, a router or a microcomputer.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Waveguide Aerials (AREA)
• Details Of Aerials (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=50624747

Family Applications (1)

Country Status (5)

Family Cites Families (4)

• 2014
  • 2014-01-10 FR FR1450175A patent/FR3016480B1/fr not_active Expired - Fee Related
• 2015
  • 2015-01-05 TW TW104100035A patent/TW201532340A/zh unknown
  • 2015-01-07 EP EP15701299.8A patent/EP3092680A1/de not_active Withdrawn
  • 2015-01-07 CN CN201580003294.6A patent/CN105849972A/zh active Pending
  • 2015-01-07 WO PCT/EP2015/050167 patent/WO2015104291A1/fr not_active Ceased

Non-Patent Citations (2)

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