Classifications

• • G—PHYSICS
  • G04—HOROLOGY
  • G04G—ELECTRONIC TIME-PIECES
  • G04G21/00—Input or output devices integrated in time-pieces
  • G04G21/04—Input or output devices integrated in time-pieces using radio waves
• • G—PHYSICS
  • G04—HOROLOGY
  • G04R—RADIO-CONTROLLED TIME-PIECES
  • G04R60/00—Constructional details
  • G04R60/06—Antennas attached to or integrated in clock or watch bodies
  • G04R60/08—Antennas attached to or integrated in clock or watch bodies inside bezels
• • 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
  • H01Q1/273—Adaptation for carrying or wearing by persons or animals
• • 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

Definitions

• the present invention relates generally to a patch type antenna for a portable electronic instrument of small volume, in particular for a timepiece.
• This antenna is more particularly intended to allow the reception of positioning and navigation signals by satellites and to be thus incorporated in a receiver of positioning and navigation signals, such a receiver compatible with the American positioning system GPS, the system of Russian positioning GLONASS or the future European satellite positioning system GALILÉO.
• the invention also relates to a portable electronic instrument comprising such a patch antenna.
• a patch antenna also called microstrip antenna
• the general shape of this type of antenna is generally parallelepiped. Excitation and ground conductors are respectively connected to this radiant element and this ground plane.
• GPS watch - An analog quartz watch fitted with a very low consumption GPS receiver
• P.-A. Farine et al. (Asulab SA), European Congress of Chronometry, CEC 2000, Geneva, 28-29 September 2000, session 7, communication 19, again presents an example of an electronic instrument in the form of a wristwatch comprising a GPS receiver and a patch antenna.
• the patch antenna is placed in the 12 o'clock zone of the watch on its ground plane itself located on the main printed circuit of the watch. The dimensions of this antenna are approximately 13 x 13 x 4 mm.
• a main aim of the present invention is thus to propose an antenna configuration for a portable electronic instrument of small volume which offers better flexibility for the design of the electronic instrument and the construction of which makes it possible, if necessary, to use metallic materials for the realization of the external covering of the instrument.
• Another object of the present invention is to provide such a solution which, however, provides a robust mechanical support for the antenna while facilitating and simplifying its electrical connection to the electronic module of the portable instrument.
• the present invention thus relates to a patch type antenna whose characteristics are set out in independent claim 1.
• the present invention also relates to a portable electronic instrument of small volume, such as a wristwatch, the characteristics of which are set out in independent claim 7.
• the ground plane of the antenna is advantageously formed of a stamped metal plate comprising at least one foot folded out of the ground plane and directly connecting the latter to the electronic module, this foot forming the conductor of mass of the antenna.
• the assembly and connection of the antenna is greatly facilitated. It is indeed not necessary to provide the instrument with a pair of separate conductors, such as a coaxial conductor, to allow excitation of the antenna, the ground conductor advantageously being an integral part of the ground plane of the 'antenna.
• the arrangement of the antenna is such that the various electronic and electrical components of the instrument are situated substantially behind the ground plane of the antenna, this proving an advantage in order to reduce interference with the antenna .
• FIG. 1 is a plan view of a wristwatch constituting a first embodiment of the invention
• FIG. 2 is a sectional view of the wristwatch taken along the section line A-A 'in Figure 1;
• FIG. 3a and 3b are respectively sectional and plan views of the patch type antenna fitted to the wristwatch of Figure 1;
• - Figures 4a and 4b are respectively sectional and plan views of the ground plane of the antenna illustrated in Figures 3a and 3b; and
• FIG. 5 is a sectional view of the type of Figure 2 illustrating a second embodiment of the invention also in the form of a wristwatch and in which the ground plane of the antenna is part part of an instrument shield plate.
• FIG. 1 shows a plan view of a portable electronic instrument according to the invention indicated overall by the reference numeral 1 and advantageously being in the form of a wristwatch.
• This wristwatch 1 is notably equipped with an antenna 20 electrically connected to an electronic module (6 in FIG. 2) placed inside the wristwatch.
• this antenna 20 is intended to allow reception of radiofrequency signals emitted by one or more distant emission sources. More particularly, this antenna is intended to allow the reception of positioning and navigation signals by satellites, such as GPS (Global Positioning System) signals coming from the American NAVSTAR system or other positioning signals by satellites coming from similar systems such as the the Russian GLONASS system or the future European satellite positioning system GALILÉO.
• GPS Global Positioning System
• the wristwatch 1 has a general appearance analogous to a conventional wristwatch and comprises, in addition to the antenna 20, a case generally designated by the reference 2, a strap (not shown) attached to the case 2, a crystal 3 under which is arranged a display device 5 enclosed in the housing 2 (such as a liquid crystal display), and control members 12 to 16, namely five push-buttons placed one (16) at 6 o'clock and the other four (12 to 15) on the periphery of the case 2.
• FIG. 2 shows a sectional view of the wristwatch 1 illustrated in Figure 1 taken along the cutting line A-A 'parallel to the axis 6 h-12 h and passing through the center of the wristwatch.
• the wristwatch 1 further comprises, arranged inside the housing 2, an electronic module 6 comprising in particular a printed circuit 60, on which are mounted the various electronic and electrical components of the instrument, as well as a source of supply 10 of electrical energy supplying in particular the electronic module 6 and the display device 5.
• the power source 10 consists of a rechargeable accumulator placed in the bottom of the housing 2.
• This power source 10 could nevertheless consist of a conventional battery (in which case a battery flap should preferably be provided in the bottom of the case in order to allow its exchange) or any other source capable of providing an adequate supply of electrical energy.
• the display device 5 namely a liquid crystal display
• the display device 5 is electrically connected to the electronic module 6 by a flexible connector 50.
• An electroluminescent sheet designated by the reference numeral 56 is interposed between the display device 5 and the electronic module 6.
• This electroluminescent sheet 56 is electrically connected to the electronic module 6 by a pair of designated connectors 57, only one of them being illustrated by way of explanation in FIG. 2.
• Each of these connectors 57 comprises a pin and a contact spring.
• the housing 2 comprises a covering body 4 having a bottom 4a and side walls 4b as well as a bezel element 7 adjusted on the covering body 4a.
• the bottom 4a and the side walls 4b are preferably made in one piece, although it is conceivable to provide two separate pieces assembled to each other, and together form, in this example, a case back of the watch bracelet 1 to which the bracelet is typically attached (not shown).
• the lens element 7 is adjusted on the covering body 4, or more exactly on the side walls 4b of the covering body 4, and supports the lens 3, the latter preferably being glued or welded to the element 7.
• this lens element 7 is made of plastic material and the lens 3 is for example welded by a known ultrasonic process.
• the spectacle element 7 is preferably tightly adjusted on the covering body, for example by means of an O-ring 30 placed between a shoulder formed on the periphery of element 7 and a similar shoulder formed on the side walls 4b of the covering body 4.
• the antenna 20 is mechanically supported by the lens element 7 and rests on an external face, designated 7a, of this element.
• This antenna 20 can optionally be glued to this outer face 7a or held by other suitable fixing means.
• the antenna 20 is advantageously placed at 12 o'clock and in an inclined position relative to the plane, designated ⁇ , in which the display device 5 and the electronic module are located. In this way, the antenna is advantageously oriented substantially towards the top in order to optimize the reception of GPS signals for the natural position of the wrist when the wearer reads the information on the display device 5.
• the element 7 also supports the control members 12 to 16 of the wristwatch.
• the wristwatch 1 further comprises an additional element 8 forming a casing circle disposed in the housing 2 between the element forming the bezel 7 and the bottom 4a of the covering body 4.
• the elements 7 and 8 form in some so the upper and lower parts of a container inside which are closed the display device 5 and the electronic module 6.
• the power source 10 is disposed between the element forming a casing circle 8 and the bottom 4a of the covering body 4. It will easily be understood that this accumulator could alternately be enclosed between the elements 7 and 8 with the display device 5 and the electronic module 6.
• the covering body 4 is made of metallic material and the lens element 7 (as well as the element 8) is made of plastic material.
• An outer covering element, designated by the reference numeral 11 (cf. FIG. 1), of essentially annular shape is further adjusted on the element 7, for example by clipping, in order to cover this element 7.
• the annular covering element 11 is preferably made of a metallic material similar to the material used for the production of the covering body 4 and has an opening 11a (indicated in FIG. 1) in which the antenna 20 is housed.
• a protective cover made of dielectric material 9 is also attached to the lens element 7 in order to protect the antenna 20 from the external environment.
• the annular covering element 11 and the cover of protection 9 could be made in one piece from a material which does not disturb the operation of the antenna 20.
• the patch antenna 20 is of essentially parallelepiped shape having a radiant element 21 separated from a ground plane 23 of larger dimension by a dielectric 22, such as a ceramic element.
• the radiant element 21 is excited by an excitation conductor 25 isolated from the ground plane 23 and passing through the dielectric 22 to be connected to the electronic module 6, the element 7 being provided with an opening 7c allowing the passage of this conductor excitation 25.
• the ground plane 23 is itself electrically connected to the electronic module by a separate ground conductor 26 also passing through the opening 7c.
• the antenna 20 thus rests on the outer face 7a of the lens element 7 by its ground plane 23.
• this type of antenna is generally placed directly on the surface of the electronic module this having the drawbacks already mentioned, namely greater interference with the electronics of the watch requiring specific shielding as well as the impossibility, if desired, of making the case from a metallic material.
• the ground plane 23 of the antenna 20 will preferably be glued to the outer face 7a of the lens element 7.
• 3a and 3b thus respectively show a sectional view and a plan view of the patch antenna 20 used in the context of the first embodiment of the 'invention.
• the excitation conductor 25 is offset from the center of symmetry of the radiant element 21, this in particular so that the antenna 20 has a circular type polarization. It will be noted that this decentring also participates in the definition of the antenna impedance.
• the distance separating the excitation conductor 25 from the ground conductor 26 is also selected in a conventional manner to allow an adequate adaptation of the antenna to the associated reception circuit.
• the ground plane 23 comprises two feet 26a and 26b extending out of the ground plane 23 and forming the ground conductor 26. It will be noted that these feet 26a and 26b are arranged so that they are arranged symmetrically on either side of the excitation conductor 25.
• the figures 4a and 4b show in more detail the structure of the ground plane 23.
• This ground plane 23 is advantageously produced from a metal plate formed by a conventional stamping process. This plate is initially cut so that it has a central opening 23a into which an extension 23b projects, having essentially the shape of a "U" opening in the central opening 23a and from which are finally formed the feet 26a, 26b.
• the structure of the ground plane 23, at the end of the cutting operation, is illustrated in broken lines in FIG. 4b, the feet being designated at this stage by the numerical references 26a * and 26b * .
• the extension 23b is subsequently folded back so that the legs 26a, 26b thus formed extend outside the ground plane 23 as illustrated.
• the excitation conductor 25 is formed so as to present a similar profile as illustrated in FIGS. 3a and 3b.
• the profile of the feet 26a, 26b and of the excitation conductor 25 is chosen so as to allow inclined positioning of the antenna 20 relative to the electronic module on which this antenna is connected.
• the ground conductor 26 forms an integral part of the ground plane 23, thus greatly simplifying the connection of the antenna 20 to the electronic module 6, although this antenna 20 does not rest directly on the electronic module 6.
• the ground conductor 26, namely the feet 26a and 26b of the ground plane 23, and the excitation conductor 25 are connected directly by welding to the printed circuit 60 of the electronic module 6, corresponding contact orifices being provided in the printed circuit 60.
• the proposed antenna connector formed of conductors 25, 26 makes it possible to define a line whose impedance is adapted between the antenna and the line (not shown) on the printed circuit 60 and thus to minimize losses by mismatch (or "mismatch loss").
• FIG. 5 shows for example another conceivable embodiment of the invention in which the ground plane of the antenna forms an integral part of a shielding plate of the portable electronic instrument.
• FIG. 5 is suitable for the production of a portable instrument provided with a covering made of non-metallic material (eg plastic), or, in general, a material which does not disturb the operation of the antenna.
• the wristwatch constituting another embodiment of a portable electronic instrument according to the invention is generally identified by the reference numeral 1 * .
• the display device 5 connected by its flexible connector 50 to the printed circuit 60 of the electronic module 6, the electroluminescent sheet placed under the display device 5, the power source 10 as well as the patch antenna 20 with its radiant element 21, its dielectric 22, its plane of ground 23 and its excitation conductors 25 and ground 26.
• These elements 5, 6, 10 and 20 are enclosed in a box designated here by the reference numeral 2 * and composed of two nested parts 4a * and 4b *.
• the lower part 4a * forms in this example a case middle of the instrument and the element 4b * attached to the upper part forms a sort of cover of the housing of the instrument 4b *.
• the instrument also comprises shielding elements 100 * and 102 * disposed respectively on the upper and lower faces of the printed circuit 60.
• the upper shielding element 100 * consists of 'a stamped metal plate of which an end portion constitutes the ground plane 23 of the antenna 20.
• the ground plane of the antenna 23 is an integral part of the antenna shielding structure. It should be noted that the antenna is always placed at a distance from the printed circuit 60 and does not rest directly on one face of this printed circuit 60.
• the antenna 20 is again arranged in a plane inclined with respect to the plane in which the display device 5 and the electronic module are located, this in order to optimize the orientation of the antenna for reception of the positioning signals during normal reading of the data displayed by the display device 5.
• the present invention is not limited to a wristwatch as illustrated in the figures, but applies to any other portable instrument which may or may not be worn on the wrist.
• the antenna is always illustrated as being placed at 12 o'clock, this antenna can obviously be placed in other eccentric positions, for example at 9 o'clock, 3 o'clock or 6 o'clock, or even on the diagonals.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Electric Clocks (AREA)
• Support Of Aerials (AREA)
• Waveguide Aerials (AREA)
• Details Of Aerials (AREA)

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ID=8180600

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• 2001
  • 2001-07-05 EP EP01202593A patent/EP1274150A1/de not_active Withdrawn
• 2002
  • 2002-06-17 US US10/571,198 patent/US20070041275A1/en not_active Abandoned
  • 2002-06-17 JP JP2003511340A patent/JP2004534239A/ja active Pending
  • 2002-06-17 DE DE60230515T patent/DE60230515D1/de not_active Expired - Lifetime
  • 2002-06-17 EP EP02743215A patent/EP1407510B1/de not_active Expired - Lifetime
  • 2002-06-17 CN CNB028134974A patent/CN1331272C/zh not_active Expired - Fee Related
  • 2002-06-17 WO PCT/EP2002/006669 patent/WO2003005484A1/en active Application Filing
  • 2002-07-04 EP EP02764633A patent/EP1407513B1/de not_active Expired - Lifetime
  • 2002-07-04 JP JP2003511342A patent/JP4044898B2/ja not_active Expired - Fee Related
  • 2002-07-04 DE DE60202213T patent/DE60202213T2/de not_active Expired - Lifetime
  • 2002-07-04 WO PCT/EP2002/007494 patent/WO2003005486A1/fr active IP Right Grant
  • 2002-07-04 CN CNB028134869A patent/CN100373696C/zh not_active Expired - Fee Related
  • 2002-07-04 US US10/478,659 patent/US6914564B2/en not_active Expired - Lifetime
• 2004
  • 2004-01-05 US US10/754,084 patent/US20040145975A1/en not_active Abandoned

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