Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/44—Details of, or arrangements associated with, antennas using equipment having another main function to serve additionally as an antenna, e.g. means for giving an antenna an aesthetic aspect
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/08—Means for collapsing antennas or parts thereof
  • H01Q1/084—Pivotable antennas
• • 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
  • H01Q1/2258—Supports; Mounting means by structural association with other equipment or articles used with computer equipment
  • H01Q1/2275—Supports; Mounting means by structural association with other equipment or articles used with computer equipment associated to expansion card or bus, e.g. in PCMCIA, PC cards, Wireless USB
• • 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
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/52—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure
  • H01Q1/521—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure reducing the coupling between adjacent antennas
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q23/00—Antennas with active circuits or circuit elements integrated within them or attached to them
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
  • H01Q5/30—Arrangements for providing operation on different wavebands
  • H01Q5/307—Individual or coupled radiating elements, each element being fed in an unspecified way
  • H01Q5/342—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes
  • H01Q5/357—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes using a single feed point
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
  • H01Q5/30—Arrangements for providing operation on different wavebands
  • H01Q5/307—Individual or coupled radiating elements, each element being fed in an unspecified way
  • H01Q5/342—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes
  • H01Q5/357—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes using a single feed point
  • H01Q5/364—Creating multiple current paths
  • H01Q5/371—Branching current paths
• • 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
  • H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
  • H01Q9/28—Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines
  • H01Q9/285—Planar dipole

Definitions

• the present invention relates to a portable compact antenna, more particularly an antenna for receiving television signals, in particular the reception of digital signals on a portable electronic device such as a laptop, a PDA (Personal Assistant) or any other device similar in need of an antenna for receiving electromagnetic signals.
• a portable compact antenna more particularly an antenna for receiving television signals, in particular the reception of digital signals on a portable electronic device such as a laptop, a PDA (Personal Assistant) or any other device similar in need of an antenna for receiving electromagnetic signals.
• Devices currently on the market generally consist of an independent antenna such as a whip or loop type antenna mounted on a housing carrying a USB connector.
• the Applicant has proposed in French Patent Application No. 05 51009 filed April 20, 2005, a compact broadband antenna covering the entire UHF band, consisting of a dipole type antenna.
• This antenna is associated with an electronic card that can connect to a portable device using a USB type connector.
• the antenna described in French Patent Application No. 05 51009 comprises a first and a second differential-powered conductor arm, one arm, said first arm, forming at least one cover for a card electronic.
• the first arm has the shape of a housing in which is inserted the electronic card comprising the processing circuits of the signals received by the dipole type antenna.
• These circuits are most often connected to a USB type connector for connection to a laptop or other similar device. Improvements to this particular antenna to achieve diversity have been proposed in French Patent Application No. 05 52401 filed on 1 August 2005 on behalf of the applicant.
• the GSM transmit band (880-915 MHz) is close to the upper limit of the UHF band (862 MHz). Indeed, unlike DVB-H systems, where it was decided to limit the UHF broadcast band for these systems at the high frequency of 698 MHz, for broadcasting DVB-T, all UHF channels and therefore the highest channels can be used.
• LNA Low Noise Amplifier
• a first solution to mitigate this problem of interference with GSM systems would be to place a filter at the input of the receiver, to reject the GSM band.
• this filter, low pass or cut band is not easy to achieve because of: i) the extreme proximity of the band to reject from the top of the useful UHF band, which imposes a very high rejection factor for this filter (order very high filter> 11 poles) ii) the need for compactness of this filter to include it inside the USB key. Indeed the more sought rejection is strong, the more the filter is bulky.
• the use of a filter with a significant rejection of the GSM band means that the frequencies located at the top of the UHF band also undergo attenuation.
• the present invention therefore proposes an antenna solution that responds in particular to the constraints of space and reception of UHF and VHF bands and for rejecting a transmission frequency band close to these bands such as the GSM band.
• the present invention relates to a portable compact antenna formed of a first dipole-type radiating element operating in a first frequency band and comprising a first and at least a second differential-fed conductor arm, the first arm, called a cold arm, forming at least one cover for an electronic card and the second arm, said hot arm, being connected to the cold arm at the power supply.
• the hot arm comprises at least one filter slot etched in the conductive portion of the hot arm and dimensioned to resonate in a second frequency band.
• the slot is a U-slot engraved in the conductive portion of the hot arm, this conductive portion may be constituted by a conductive U-shaped element made on an insulating substrate as described in the French patent application filed on same day as the present application and entitled "Portable Compact Antenna for Digital Terrestrial Television".
• the first frequency band is the UHF band (band between 470 and 862 MHz) and the second frequency band is the GSM band (band between 880 and 915 MHz).
• the hot arm has several slots of different length so that each of the slots resonates at different frequencies, etched in the conductive portion of the hot arm, which allows the broadening of the rejection of the second frequency band.
• the end of the slot may be modified so that it ends in two slots of different lengths. In this case, the slot resonates at two near frequencies, which makes it possible to widen the width of the rejection band.
• a second radiating element consisting of a conductive element bent in meanders, as described in the French patent application. filed the same day as the present application, can be made between the branches of the U-shaped element.
• the second radiating element is sized to operate in a third frequency band such as the VHF band, more particularly VHF-III (174-225-230 MHz).
• FIG. 1 is a schematic perspective view of an antenna as described in French Patent Application No. 05 51009 in the name of the Applicant.
• FIG. 2 is a schematic perspective view of another embodiment of an antenna such as that of FIG.
• FIG. 3 is a schematic perspective view of a first embodiment of an antenna according to the present invention.
• FIG. 4 represents the real and imaginary parts of the simulated antenna 3 in the 400 MHz - 1000 MHz frequency band.
• FIG. 5 is a schematic view of an adaptation circuit used at the antenna output.
• FIG. 6 represents the yield curves of the antenna of FIG. 3.
• FIG. 7 represents the gain and directivity curves obtained by simulating an antenna according to FIG.
• FIG. 8 represents the offset of the efficiency of the antenna provided by the slot according to the present invention.
• FIG. 9 shows a second embodiment of an antenna according to the present invention and operating in the UHF and VHF band with GSM rejection.
• FIG. 10 represents the radiation efficiency of the antenna of FIG. 9.
• FIG. 11 is a schematic view of an adaptation circuit used with the antenna of FIG. 9.
• FIG. 12 represents the yield curves of the antenna of FIG.
• FIG. Figure 13 shows the gain and directivity curves of the antenna of Figure 10.
• FIG. 14 represents the radiation patterns respectively in the UHF and VHF bands obtained by simulation of an antenna according to FIG. 10.
• FIGS. 15, 16, 17, 18 and 19 represent alternative embodiments of an antenna according to the invention.
• FIG. 20 is a schematic representation of an electronic card used with the antennas according to the present invention.
• this dipole antenna comprises a first conducting arm 1 also called a cold arm and a second conducting arm 2 also called a hot arm, the two arms being connected to one another via a hinge zone 3 located at one end of each of the arms.
• the arm 1 has substantially the shape of a housing for receiving in particular an electronic card, an embodiment of which will be described later.
• the housing has a portion 1a of substantially rectangular shape, extending by a curved portion 1b flaring gradually so that the energy is radiated gradually, which promotes adaptation to a wider frequency band.
• the length L1 of the arm 1 is substantially equal to ⁇ 1 / 4 where ⁇ 1 represents the wavelength at the central operating frequency.
• the length L1 of the arm 1 is close to 112 mm for operation in the UHF band (frequency band between 470 and 862 MHz).
• the antenna comprises a second arm 2 rotatably mounted around the axis 3 which also represents the point of connection of the antenna to the signal processing circuit, namely to the electronic card, not shown. inserted in the housing formed by the arm 1.
• the electrical connection of the antenna is made by a metal wire, for example a coaxial cable or the like, while the axis of rotation 3 is made of a material relatively transparent to electromagnetic waves.
• the articulable arm 2 about the axis 3 has a length L1 substantially equal to ⁇ 1 / 4.
• the arm 2 also has a curved profile followed by a flat rectangular part for folding it completely against the arm 1 in the closed position.
• the arm 2 being rotatably mounted at 3 with respect to the arm 1, this makes it possible to modify the orientation of the arm 2 so as to optimize the reception of the television signal.
• FIG. 2 A further embodiment of a dipole antenna will now be described with reference to FIG. 2, this embodiment being the subject of the patent application filed on the same day as the present application and having the title "Antenna compact notebook for digital terrestrial television.
• the antenna comprises a first arm 1 said cold arm having the shape of a housing and a second arm, said hot arm, connected to the arm 1 by a hinge 3.
• the hot arm is constituted by a U-shaped element 21 made of conductive material, produced on an insulating substrate 20.
• the substrate consists of a material known under the name "KAPTON" covered with a copper layer which is etched to produce the U-shaped element.
• each branch of U 21 has a length substantially equal to ⁇ 1 / 4.
• the U-shaped element is connected at the joint 3, by an electrical connection element such as a metal wire, to a not shown electronic card inserted inside the cold arm. 1 forming a housing.
• an electrical connection element such as a metal wire
• the antenna of Figure 2 is sized to operate in the UHF band.
• This antenna therefore comprises a first arm 1 or cold arm having, like the cold arm 1 of FIGS. 1 and 2, the shape of a housing made of conductive material that can receive an electronic card.
• the cold arm 1 is extended by a second arm, called hot arm which, in the embodiment shown, is of the same type as the hot arm 20 of Figure 2.
• the hot arm 20 is constituted by a U-shaped conductive element 21 made on an insulating substrate.
• the U-shaped conductive element 21 can be etched in the metal layer covering a "Kapton" substrate.
• This hot arm 20 is rotatably connected to the cold arm 1 via an axis 3 at which the electrical connection is made.
• a slot 40 is formed on the U-shaped conductive member 21 of the hot arm 20.
• This slot is sized to resonate in a narrow band around a given frequency, namely the GSM frequency in one embodiment of the invention. the invention. More specifically, the slot 40 is a U-shaped slot in the U-shape of the conductive element 21.
• the width of the slot makes it possible to adapt the level of rejection.
• the antenna of Figure 3 was simulated on the electromagnetic IE3D software which is based on the method of moments, in the frequency band (400 MHz - 1000 MHz). The results of the simulation are given in FIG. 4 which represents the real and imaginary parts of the antenna showing a resonance at 900 MHz.
• Complementary simulations have been performed using an adaptation circuit as shown in FIG. 5 between the antenna and the low-noise amplifier of the electronic card.
• This circuit comprises a capacitor C1 of 12 pF connected in series between the output antenna A and a point p, an inductor L1 of 42 nH mounted between the point p and the ground, a second 1.6 pF C2 capacitor connected in series between the point p and a point p1 of connection to the LNA of the electronic card and a parallel circuit LC formed of a capacitance C3 of 1 pF and a self-inducting L2 of 14 nH, mounted between the point p1 and the mass.
• the curve D1 of FIG. the total efficiency of the antenna in the UHF band with the matching cell is greater than 65% with a very good rejection of the GSM band since the efficiency around 900 MHz is between 1 and 10%.
• Curve D2 shows a rejection around 900 MHz from the radiation yield of the antenna.
• the curve D3 of FIG. 7 shows a gain of the antenna in the vicinity of 0 dBi in the UHF band and a rejection between 10 dB and 20 dB around the GSM band, namely close to 900 MHz.
• the simulations carried out show that it is necessary to refocus the rejection band around 900 MHz. It is, in fact, necessary to take into account the technology used to make the device, in particular the permittivity of the materials used to make the second arm.
• a second embodiment of the present invention will now be described with reference to FIGS. 9 to 14 for operating also in a third frequency band such as the VHF band.
• This embodiment proposes, as in the French patent application filed on the same day as the present, to make between the branches of the U-shaped element of the hot arm, a second radiating element consisting of a conductive element bent into meanders.
• This conductive element is sized to operate in the VHF frequency band, more particularly the VHF-III frequency band (174-230 MHz).
• the total electrical length of the meandering conductive element is equal to k * ⁇ 2 / 2-L1 where ⁇ 2 is the wavelength at the center frequency of the third frequency band, L1 the length of the cold arm and k a positive integer representing a harmonic of the third frequency band.
• the antenna comprises a cold arm 1 only a part of which is shown, and a hot arm 20, the two arms being connected by the hinge 3 at the level of the connection to the circuits. exploitation.
• the hot arm 20 comprises on an insulating substrate a U-shaped conductive element 21 into which a U-shaped slot 40 has been etched as for the embodiment of FIG. 2.
• a meandering conductive element 50 is formed between the branches of the U-shaped conductive element 21.
• the meander element 50 is formed such that the meander portions 50 'of the smallest length are parallel to the branches 21, since the orthogonal directions currents flowing in the meanders and at the edges of the U conductor greatly reduce the coupling. This is confirmed by the simulation results given by the curve of FIG. 10 which gives the efficiency of the antenna of FIG. 9.
• an adaptation circuit as shown in FIG. 11 is mounted between the antenna A and the low noise amplifier LNA.
• the matching circuit comprises a capacitance C'1 of 2pF mounted between the antenna output point p 'and the ground, an inductor L 1 of 35 nH connected in series between the point p' and a point p'1 , a second capacitance C'2 of 35 pF mounted between the point p'1 and the ground, a second inductor L'2 mounted between the point p'1 and a point p'2 of connection to the amplifier LNA and a third self The 3 rise between the point p'2 and the mass.
• the curve D'1 represents the efficiency of the simulated antenna of FIG. 9 with the matching circuit of FIG. 11. A yield greater than 65% is thus obtained with a good rejection around 900 MHz. (GSM band).
• the curve D'2 represents the rejection obtained around 900 MHz and derived from the radiation efficiency of the antenna.
• the curve C'3 shows a gain of the antenna in the vicinity of OdB in the UHF band, a rejection between 1OdB and 2OdB in the GSM band around 900 MHz and a gain of the order of 1OdBi in the VHF band.
• Figure 14 shows the VHF and UHF band radiation patterns of the simulated antenna of Figure 9. These diagrams show the omnidirectional nature of the antenna radiation.
• Figures 15 to 17 show different embodiments of an antenna according to the invention.
• the second radiating element 50 ' is formed by a meandering conductor element whose meander gap is changed.
• the length of the zone 50 ' is reduced and the coupling between this zone and the branches of the U-shaped conductive element 21 can be limited.
• FIG. 21 perspective view of another embodiment of an antenna according to the invention and a longitudinal section of the hot arm.
• the two antenna patterns namely the U-shaped conductive element 21 and the second radiating element 50.
• an excess thickness 60 of plastic material is deposited at above the slot (not shown) formed in the U-shaped conductive element 21.
• FIGS. 1 or 2 The other parts of the antenna, namely the cold arm 1 and the hinge zone, are identical to those of FIGS. 1 or 2.
• Figures 18 and 19 have been shown alternative embodiments of the rejection slot.
• three slots 40, 41 and 42 of different lengths have been etched in the U-shaped conducting element 21 of the hot arm 20 containing a second radiating element 50.
• the three slots 40, 41 and 42 having different electrical lengths resonate on different frequencies. It is therefore possible to expand the rejection of the GSM band.
• FIG 19 there is shown the end of a slot 40 formed on the conductive element 21 in U.
• the end is divided into two parts 4OA and 4OB of different length.
• the slot then resonates at two frequencies, which makes it possible to widen the rejection bandwidth.
• an embodiment of an electronic card of dimensions 70-80 mm by 15-25 mm which can be introduced into the housing formed by the cold arm 1 and connected to the antenna.
• This electronic card 100 comprises a low-noise amplifier LNA 101 to which the coaxial cable of the antenna is connected at the joint 3.
• the LNA 101 is connected to an integrated tuner 102 processing both the VHF band and the band UHF.
• the tuner 102 is connected to a demodulator 100 whose output is connected to a USB interface 104, itself connected to a USB connector 105. It is therefore possible with this system to connect the antenna to the USB input of a laptop or other display element, which can receive especially digital terrestrial television on a computer, a PDA or any other portable device.

Applications Claiming Priority (2)

Publications (1)

Family

ID=37606956

Family Applications (1)

Country Status (7)

Cited By (1)

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• 2006
  • 2006-05-12 FR FR0604270A patent/FR2901064A1/fr active Pending
• 2007
  • 2007-05-04 WO PCT/FR2007/051226 patent/WO2007135312A1/fr active Application Filing
  • 2007-05-04 EP EP07766006A patent/EP2018680A1/de not_active Withdrawn
  • 2007-05-04 CN CN200780017323XA patent/CN101443953B/zh not_active Expired - Fee Related
  • 2007-05-04 BR BRPI0711189-4A patent/BRPI0711189A2/pt not_active IP Right Cessation
  • 2007-05-04 JP JP2009508438A patent/JP4912458B2/ja not_active Expired - Fee Related
  • 2007-05-04 US US12/227,245 patent/US7956816B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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