Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
  • H01Q13/10—Resonant slot antennas
  • H01Q13/106—Microstrip slot antennas
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
  • H01Q13/10—Resonant slot antennas
  • H01Q13/12—Longitudinally slotted cylinder antennas; Equivalent structures
• • 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
  • 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
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
  • H01Q13/10—Resonant slot antennas

Definitions

• the present invention relates to a device for receiving and / or transmitting electromagnetic signals, more particularly a device comprising reception and / or transmission means constituted by a slot-type antenna, which can be used in the field of wireless transmissions, particularly in home networks, but also as the basic element of a circularly polarized antenna having a wide frequency band.
• the antennas do not need to have a high purity of polarization.
• the frequency bandwidth requested can be significant.
• two disjoint frequency bands have been allocated in Europe according to the BRAN / HIPERLAN2 standard and in the United States, according to the IEEE-802.1 1 A standard. completely these frequency bands, the antenna must operate on a bandwidth of at least 575 MHz for Europe and at least 675 MHz for the United States. Consequently, the frequency band should be approximately 11% and 12.3% of the operating frequency, respectively.
• antennas On the other hand, if one wishes to produce equipment at low cost and in large numbers using these. antennas, additional margins are necessary to take into account the influence of variations on the parameters of the substrate and the manufacturing tolerances on the central frequency of the antenna. Therefore, the relative bandwidths sought are of the order of 15 to 20%
• antennas of the printed antenna type it is known to use antennas of the printed antenna type. However, the printed antennas operate in a narrow frequency band.
• the performance in terms of bandwidth namely the frequency band for which the reflection coefficient S 1 1 at the antenna excitation point is less than -10dB, are mainly fixed by the parameters of the substrate used such as relative permittivity, thickness or the like and the choice of the radiating element, which may be a patch or "patch", a slit or the like.
• slot type antennas make it possible to obtain simple antenna structures at reduced cost and having relatively larger bandwidths than other printed structures.
• antennas of the slot type more particularly the antennas constituted by an annular or polygonal slot, can radiate according to a circular polarization.
• circular polarization can be obtained in two ways:
• the generation of the circular polarization being obtained by the introduction of a disturbance such as a notch or a protuberance in a plane situated at 45 ° from the excitation point.
• FIGS. 1 a and 1 b An antenna of this type is shown in FIGS. 1 a and 1 b which respectively concern a plan view from above and a section view of an antenna of annular slot type, supplied by micro-ribbon line, provided with notches for get circular polarization. More specifically, the antenna is formed by a substrate 1 on one face of which a metal layer 3 has been deposited in which a radiating element of the annular slot type 2 has been made.
• This annular slot is supplied by a line of supply 3 produced by metallic deposition on the other face of the substrate 1.
• This supply line supplies the radiating element 2 by electromagnetic coupling at point A between line 3 and the slot 2.
• the dimension of the line between point A and the end of the line is about ⁇ m / 4 where ⁇ m is the guided wavelength for the line.
• the slot 2 has two diametrically opposite notches 4 and lying in a plane situated substantially at 45 ° from the excitation point A.
• this disturbance makes it possible to separate, in the frequency domain, the two modes orthogonal initially degenerate.
• the method using a two-point excitation makes it possible to obtain a good rate of ellipticity or ARBW (for Axial Ratio Bandwidth in English) with an enlarged adaptation band.
• the present invention therefore aims to provide a new device for receiving and / or transmitting electromagnetic signals comprising a radiating element consisting of an annular slot antenna and a supply line which allow to obtain a circular polarization on adaptation bandwidths much greater than the bandwidths obtained with the devices of the prior art. Consequently, the subject of the present invention is a device for receiving and / or transmitting electromagnetic signals comprising at least one means for receiving and / or transmitting electromagnetic signals constituted by a slot antenna and a supply line. electromagnetically coupled with the slot for connecting the means for receiving and / or transmitting electromagnetic signals to signal processing means, characterized in that the supply line is electromagnetically coupled with the slot-type antenna , at two chosen points such that the electromagnetic waves have a circular polarization.
• the length of the slit between the two coupling points is of the order of ⁇ s / 4 with ⁇ s the wavelength guided in the slit, in the case of a slit with a perimeter ⁇ s, i.e. a quarter of the perimeter of slot,
• the length of the line between the two coupling points is of the order of ' ⁇ m / 4 with ⁇ m the wavelength guided under the supply line and k' an odd integer and,
• the length between the end of the supply line and the first coupling point is of the order of ⁇ m / 8 modulo ⁇ m / 2 with ⁇ m the wavelength guided under the supply line and ends with an open circuit.
• the device comprises several means for receiving and / or transmitting electromagnetic signals constituted by a slot antenna nested in each other and a supply line electromagnetically coupled with the slot of each means in two points chosen such that the electromagnetic waves emitted by each means have a circular polarization.
• the supply line is a microstrip line or a coplanar line and the means for receiving and / or transmitting electromagnetic waves constituted by a slot-type antenna include slots of annular or polygonal shape such as square, rectangular, diamond-shaped or similar.
• FIGS. 1a and 1b respectively represent a plan view from above. and a sectional view of a device according to the prior art
• FIGS. 2a and 2b respectively represent a plan view from above and a sectional view of a first embodiment of a device according to the present invention
• FIG. 3 is a curve giving the modulus of the reflection coefficient S1 1 expressed in dB as a function of the frequency of the device of FIG. 2
• FIG. 4 is a curve giving the ellipticity rate for the devices of FIGS. 1 and 2
• FIGS. 5 and 6 are top plan views of two alternative embodiments of the present invention.
• a device for receiving and / or transmitting circularly polarized electromagnetic signals in accordance with the present invention consists of an antenna of the annular slot type 12, which is supplied by electromagnetic coupling by a supply line 13 connected at the level of port 1 to means for processing signals well known to those skilled in the art.
• annular slot 12 has been made in this metallization.
• the annular slot 12, as shown in FIG. 2a, has a perimeter of the order of ⁇ s. This annular slot therefore operates in its fundamental mode.
• ⁇ s is chosen so that the central operating frequency is around 5.8 GHz.
• a supply line has been produced by depositing a metallization.
• This supply line 13 is positioned so as to be electromagnetically coupled with the slot 12 at two points A1, A2 which are at 90 ° from one another.
• the length of the slit between the two points A1 and A2 is of the order of ⁇ s / 4 with ⁇ s the wavelength guided in the slit, in the case of a slit with a perimeter ⁇ s, i.e. quarter of the perimeter of the slot.
• the length of the excitation line 13 between the two coupling points A1 and A2 is of the order of k' ⁇ m / 4 where ⁇ m is the guided wavelength of the supply line 13 and k 'is an odd integer.
• the power line 13 is constituted by a microstrip line, in the embodiment shown is To obtain this value, the width of the microstrip line is optimized.
• the wavelength between the end of the supply line 13 and the coupling point A1 is of the order of ⁇ m / 8 modulo ⁇ m / 2 with ⁇ m the wavelength guided by the supply line 13.
• This supply line 13 ends in an open circuit.
• the overflow of the line beyond point A2 makes it possible to adapt the annular slot to the measuring devices used.
• the supply line 13 produced in microstrip technique has a characteristic impedance Zm ⁇ 134.5 ohms, a width of 0.2 mm and cuts the annular slot at a distance from the point of tangency parallel to the line of 1.895 mm .
• the simulation results are given for the reflection coefficient S 1 1 by the curve shown in FIG. 3.
• Figure 4 there is shown the ellipticity rate, namely the AR-BW for a conventional device as shown in Figures 1, consisting of a slot with a notch and for a device according to the present invention, as shown in Figures 2, consisting of a slot coupled to a supply line placed in a specific manner.
• the results obtained in Figure 4 show that the AR-BW of the two antennas are equivalent with a slight shift in the operating frequency.
• FIG. 5 there is shown a top plan view of another embodiment comprising two means for receiving and / or transmitting electromagnetic waves of circular polarization nested one inside the other.
• first annular slot 20 and a second annular slot 21 the two slots being supplied by a common supply line 22 produced in microstrip technique.
• This supply line 22 is electromagnetically coupled with the slots 20 and 21 according to the criteria making it possible to obtain circularly polarized waves.
• the line 22 is coupled with the annular slot 20 at the points P1 and P2, so that the length between P1 and P2 is of the order of k' ⁇ m / 4 where ⁇ m is the guided length of the line.
• the length of the slot 20 between P2 and P1 is chosen to be of the order of ⁇ s / 4 where ⁇ s is a function of the operating frequency f1 of the antenna 20 in its background mode and the supply line 22 between P2 and the end of line 22 in open circuit is of the order of ⁇ m / 8 modulo ⁇ m / 2 where ⁇ m is the wavelength guided under line 22.
• the line 22 is also electromagnetically coupled with the slot 21 at two points P3 and P4 chosen so that the line length between P4 and P3 is of the order of k " ⁇ m / 4, the length of the slot between P4 and P3 or of the order of ⁇ 's / 4, where ⁇ 's is a function of the operating frequency f2 of the antenna 21 in its fundamental mode and the line length between P4 and the end of the line 22 is of the order of ⁇ m / 8 modulo ⁇ m / 2.
• the perimeters of the two slots 20, 21 give the two operating frequencies of the two antennas and the specific coupling of the supply line 22 with the two slots makes it possible to obtain operation in circular polarization at the two different frequencies such that f1 and f2 ..
• the two slots 20, 21 are nested so that the length L1 of the microstrip line at the frequency f1 between the open circuit and the middle of the two points of intersection P2-P1 with the slot 20 is equal to the length L2 of the microstrip line at the frequency f2 between the open circuit and the middle of the two points of intersection P3-P4 with the slot 21.
• L1 is of the order of k ⁇ m1 / 4 (k odd integer) and L2 is of the order of k ⁇ m2 / 4 (k odd integer). Therefore, according to the relationships between L1 and L2 and the choice of the values k 'and k ", different configurations can be envisaged for the nested slots which can for example be tangent at a point or have a line supply structure in niche.
• the slot 30 is constituted by a polygon such as a rhombus, which is supplied by a supply line 31 which cuts the rhombus so as to meet the construction criteria in accordance with the present invention.
• the present invention has been described with reference to particular embodiments.
• the shape of the slot-type antenna can be modified in many ways, in particular the slot can be constituted by a square, a rectangle or any other similar polygon and that the line supply can also be carried out in a different technology such as coplanar technology.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Waveguide Aerials (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)

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• 2001
  • 2001-12-19 FR FR0116469A patent/FR2833764B1/fr not_active Expired - Fee Related
• 2002
  • 2002-12-17 WO PCT/FR2002/004376 patent/WO2003052872A1/fr active Application Filing
  • 2002-12-17 AU AU2002364996A patent/AU2002364996A1/en not_active Abandoned
  • 2002-12-17 US US10/499,638 patent/US7227507B2/en not_active Expired - Fee Related
  • 2002-12-17 KR KR1020047009537A patent/KR100970692B1/ko not_active IP Right Cessation
  • 2002-12-17 EP EP02804930A patent/EP1470614A1/fr not_active Ceased
  • 2002-12-17 CN CN028258894A patent/CN1608333B/zh not_active Expired - Fee Related
  • 2002-12-17 JP JP2003553663A patent/JP4147192B2/ja not_active Expired - Fee Related
• 2007
  • 2007-01-18 US US11/654,891 patent/US20070115193A1/en not_active Abandoned

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