Abstract:
An antenna support to be mounted on an electrical board and used to carry an antenna which is electrically connected to the board. The support has a plurality of housings, each one suitable for receiving the antenna according to different orientations; device for adjusting the position of the antenna on the board; and device for fixing the support to the board. An electrical board provided with an antenna support, a method for positioning an antenna to be connected to an electrical board, and a method for producing an electrical board connected to an antenna are also provided.

Description:
[0001]    The invention relates to the field of transmitting information wirelessly, and it seeks more particularly to provide: an antenna support; an electric circuit card provided with such a support; a method of placing an antenna; and a method of fabricating an electric circuit card fitted with an antenna. 
       BACKGROUND OF THE INVENTION 
       [0002]    A home electronic appliance, such as an Internet gateway of the set-top-box or ADSL box type conventionally comprises a casing incorporating at least one electric circuit card and an antenna that is connected to the electric circuit card to enable the electronic appliance to exchange data with other electronic appliances (e.g. belonging to the same WiFi type wireless network). 
         [0003]    The placing of the antenna on the card or in the casing is generally defined during a design stage preceding the design of the printed circuit of the card, with said prior design stage also involving stages of designing the electrical circuit for the card, performing radio simulations, modeling, testing, etc. 
         [0004]    The placing of the antenna is thus already frozen at the time the printed circuit is designed and fabricated, the electronic components are soldered on the card, and the card is incorporated together with the antenna in the casing. Unfortunately, it can happen that the operation of the system formed by the card and the antenna differs from what was expected, e.g. because of interference being underestimated between the antenna in question and another antenna on the card, or as a result of a late mechanical modification to the casing having an influence on the radiation pattern of the antenna, etc. When such a phenomenon requires the placing of the antenna to be modified, it is necessary to design and fabricate a new printed circuit, which tends to increase the cost of developing an electronic appliance. 
       OBJECT OF THE INVENTION 
       [0005]    An object of the invention is to reduce the cost of developing an electronic appliance including an electric circuit card connected to an antenna. 
       SUMMARY OF THE INVENTION 
       [0006]    In order to achieve this object, the invention provides an antenna support for mounting on an electric circuit card and for carrying an antenna that is electrically connected to the card, the support comprising:
       a plurality of housings, each adapted to receive the antenna in a distinct orientation;   adjustment means for adjusting the position of the antenna on the card;   means for fastening the support on the card.       
 
         [0010]    Thus, the orientation of the antenna and the position of the antenna on the card are not already frozen at the time the printed circuit of the card is designed and fabricated. If the operation of the system formed by the card and the antenna differs from the expected operation, then the antenna support of the invention makes it possible to modify the orientation of the antenna by installing it in another housing, or to modify the position of the antenna on the card by using the means for adjusting the support. 
         [0011]    The invention also provides an electric circuit card provided with an antenna support as described above, said antenna support being adapted to carry an antenna that is electrically connected to the electric circuit card. 
         [0012]    The invention also provides a method of placing an antenna that is for connection to an electric circuit card, the method comprising the steps of:
       installing the antenna in a housing of an antenna support as described above;   mounting the support on the card;   taking a radio measurement in order to evaluate a parameter that is representative of the quality of the placing of the antenna;   modifying the orientation of the antenna and/or the position of the support in order to improve said parameter.       
 
         [0017]    Finally, the invention provides a method of fabricating an electric circuit card connected to an antenna, the method comprising the steps of:
       fabricating a printed circuit card;   mounting the electronic components of the card on the printed circuit;   placing the antenna by using the placing method according to the preceding claim;   fastening the support to the card.       
 
         [0022]    The invention can be better understood in the light of the following description of a particular, non-limiting embodiment of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    Reference is made to the accompanying drawings, in which: 
           [0024]      FIG. 1  shows an electric circuit card and the antenna support of the invention mounted on said electric circuit card; 
           [0025]      FIG. 2  is a rear view in perspective of the antenna support of the invention receiving a flat-plate antenna parallel to the electric circuit card; 
           [0026]      FIG. 3  is a view analogous to the view of  FIG. 2 , in which the flat-plate antenna is received perpendicularly to the card; 
           [0027]      FIG. 4  is a front perspective view of the antenna support of the invention, said support not carrying an antenna; 
           [0028]      FIG. 5  is a rear perspective view analogous to the view of  FIG. 4 ; 
           [0029]      FIG. 6  is a cutaway view showing the electric circuit card fitted with the antenna support of the invention and a casing in which the card is incorporated; and 
           [0030]      FIG. 7  shows an antenna support of the invention in a second embodiment having conductive pads coming into contact with tracks on the card in order to connect the antenna electrically in the card. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    With reference to  FIGS. 1 to 6 , the antenna support  1  of the invention is for mounting on an electric circuit card  2  and for carrying an antenna  3  that is electrically connected to the electric circuit card  2 . The antenna  3  in this example is a flat-plate antenna as used for transmitting data using a WiFi protocol. The electric circuit card  2  and the antenna  3  are incorporated in a casing  10  (visible in  FIG. 6 ) of a home electronic appliance of the set-top-box type. The electric circuit card  2  is itself constituted by a printed circuit having some number of various electronic components  4  soldered thereto, including a data processor connected to radio frequency components (transceiver, etc.) that are directly connected to the antenna  3 . 
         [0032]    The antenna support  1  extends over a length L and over a height h that is less than the length L. A front face F 1  of the antenna support  1  is defined that extends facing the electric circuit card  2  when the antenna support  1  is mounted on the electric circuit card  2 , and a rear face F 2  of the antenna support  1  is defined that extends facing a side face of the casing  10  when the electric circuit card  2  and the antenna support  1  are incorporated in the casing  10 . 
         [0033]    The antenna support  1  presents a bottom portion  7  having a substantially plane bottom face  8  of generally rectangular shape that is to bear against the electric circuit card  2 , and a top portion  9  cantilevered out over the electric circuit card  2  and defining a first housing  11  for receiving the antenna  3  so that it extends parallel to the electric circuit card  2 . 
         [0034]    The first housing  11  has a first flat bottom wall  12  parallel to the bottom base  8 . The first bottom wall  12  is generally rectangular in shape and of area greater than the area of the bottom base  8 , and it is surrounded by first rims  14  projecting perpendicularly from the first bottom wall  12 . 
         [0035]    The antenna support  1  has a second housing  15  for receiving the antenna  3  in such a manner that it extends perpendicularly to the electric circuit card  2 . The second housing  15  extends over the rear face F 2  of the antenna support  1  and is defined in an intermediate portion of the antenna support  1  connecting together the top portion  9  and the bottom portion  7 . Like the first housing  11 , the second housing  15  has a second flat bottom wall  16  of shape that is generally rectangular and of area S, extending perpendicularly to the first bottom wall  12 . The second bottom wall  16  is surrounded by second rims  17  projecting perpendicularly from the second bottom wall  16 . 
         [0036]    Each of the first and second housings  11  and  15  is adapted to receive the antenna  3  in a distinct orientation. In this example, the first housing  11  is adapted to receive the antenna  3  parallel to the electric circuit card  2 , while the second housing  15  is adapted to receive the antenna  3  perpendicularly to the electric circuit card  2 . 
         [0037]    Each of the first and second housings  11  and  15  is provided with a respective notch  19 , said notches  19  being formed respectively in a first rim  14  situated in the vicinity of the rear face F 2  of the antenna support  1  and in a second rim  17 . These notches  19  are for guiding an electric wire  21  connecting the antenna  3  of the electric circuit card  2 . These notches  19  make it possible to control very accurately the length, the position, and the stiffness of the electric wire  21 . 
         [0038]    Each of the first and second housings  11  and  15  has keying means for preventing the electric circuit card  2  fitted with the antenna support  1  and an antenna  3  installed in a wrong housing of the support  1  from being mounted in the casing  10 . In this example, the keying means comprise two first slots  22  situated in the first bottom wall  12  of the first housing  11  and two second slots  23  situated in the second bottom wall  16  of the second housing  15 . The first slots  22  are perpendicular to the second slots  23 , which extend in continuity with the first slots  22 . The first and second slots  22  and  23  are designed to co-operate with complementary tongues  24  of the casing  10 . When the antenna  3  of the electronic appliance is supposed to be mounted in the first housing  11 , the tongues  24  of the casing  10  are positioned on a side face of the casing  10  so that they are inserted into the second slots  23  when the electric circuit card  2  and the antenna support  1  are incorporated in the casing  10 . This situation corresponds to the tongues  24  shown in continuous lines in  FIG. 6 . Thus, when an operator incorporates the electric circuit card  2  with the antenna  3  in the casing  10 , if the antenna  3  is wrongly positioned in the second housing  15  instead of in the first housing  11 , then the tongues engage the antenna  3 , thereby preventing assembly and warning the operator that the antenna is not mounted in the correct housing. Likewise, when the antenna  3  of the electronic appliance is supposed to be mounted in the second housing  15 , the tongues  24  of the casing are positioned on the lid of the casing  10  so that they become inserted into the first slots  22  when the electric circuit card  2  and the antenna support  1  are incorporated in the casing  10 . This situation corresponds to the tongues  24  drawn in dashed lines in  FIG. 6 . Thus, if the antenna  3  is wrongly positioned in the first housing  11 , then at the time of incorporation the tongues will engage the antenna  3  and prevent the lid of the casing  10  being put into place properly. 
         [0039]    The antenna support  1  also has means for adjusting the position of the antenna  3  on the electric circuit card  2 , which means are situated in the bottom portion  7  of the antenna support  1 . The term “position of the antenna” is used herein to mean the position of the antenna along an edge  26  of the electric circuit card  2 , independently of the orientation of the antenna. These adjustment means comprise a slideway  25  co-operating with the edge  26  of the electric circuit card  2  when the antenna support  1  is mounted on the card  2 . The slideway  25  has a bearing plane  27 , specifically formed by a top face of the base  8  of the antenna support  1 , and a plane counter bearing face  28 . The slideway  25  enables the position of the antenna support  1  to be modified while it is being mounted on the electric circuit card  2  by causing the antenna support  1  to slide along the edge  26 , thus enabling the position of the antenna support  1  to be modified. The plane of the counter bearing face  28  has a first chamfer  32  for facilitating insertion of the edge  26  of the electric circuit card  2  in the slideway  25  when mounting the antenna support  1  on the electric circuit card  2 . 
         [0040]    The antenna support  1  also has means for fastening the antenna support  1  on the electric circuit card  2  enabling the antenna support  1  to be fastened once its position along the edge  26  of the electric circuit card  2  is defined. The fastening means comprise two flexible tabs  29 , each provided with a fastener peg  30  that extends in line with the plane bearing face  27  of the slideway  25 . A position for fastening the antenna support  1  is defined on the electric circuit card  2  by fastening orifices  31  formed for this purpose in the electric circuit card  2 . It should be observed that each flexible tab  29  has a second chamber  34  for facilitating insertion of the edge  26  of the electric circuit card  2  in the slideway  25 . 
         [0041]    When the antenna support  1  is mounted on the electric circuit card  2  and is not yet in a fastening position, the flexible tabs  29  are inclined by the action of the electric circuit card  2  on the fastener pegs  30  of the flexible tabs  29 , thereby enabling the antenna support  1  to be slid along the edge  26  of the electric circuit card  2 . When the antenna support  1  is located on the card  2  in a fastening position, the fastener pegs  30  are received in the fastener orifices  31 , thereby enabling the antenna support  1  to be fastened on the electric circuit card  2 . 
         [0042]    It should be observed that the antenna support  1  has two protuberances  33  situated extending the base of the antenna support  1 . These protuberances  33  enable the antenna support  1  to be fastened on an element that might be different from an electric circuit card, e.g. on a mechanical element situated in the bottom of the casing  10  and provided for this purpose. In order to fasten the antenna support  1 , the protuberances  33  co-operate by way of example with slideways or with a clip fastener system or they may receive screws. 
         [0043]    In a second embodiment, shown in  FIG. 7 , the base  8  of the antenna support  1 ′ is provided in the plane bearing surface  27  with two first conductor elements  35  that are electrically connected to the antenna  3 , specifically two conductor pads  35 , and the printed circuit of the electric circuit card  2  has two second conductor elements  36 , specifically two parallel tracks  36  that are not varnished and that run along the edge  26  of the card  2 . When the antenna support  1 ′ is mounted on the electric circuit card  2 , the pads  35  and the parallel tracks  36  thus come into contact and the antenna  3  is thus electrically connected to the electric circuit card  2 . It is thus possible to modify the position of the antenna support  1 ′, and even to slide the antenna support  1 ′, while maintaining this electrical connection (providing the pads  35  remain in contact with the tracks  36 ). 
         [0044]    There follows a description in greater detail of certain advantageous uses of the antenna support of the invention. 
         [0045]    The antenna support  1 ,  1 ′ is particularly well adapted to defining the placing of an antenna  3  that is to be connected to an electric circuit card  2 . The term “placing” is used herein to cover both the orientation of the antenna  3  and the position of the antenna  3  on the card  2 , with the term “position” being understood as defined above. 
         [0046]    The method of placing an antenna  3  of the invention begins with a step of installing the antenna  3  in a housing  11 ,  15  of the antenna support  1 ,  1 ′ that is adapted to receive the antenna  3  in a preferred orientation, which preferred orientation may be defined by way of example as a result of a prior design stage. 
         [0047]    Thereafter, the placing method comprises a step of mounting the antenna support  1 ,  1 ′ on the electric circuit card  2  at a certain position along the edge  26  of the electric circuit card  2 . 
         [0048]    Thereafter, the placing method comprises a step of taking radio measurements in order to evaluate a parameter representative of the quality with which the antenna  3  is placed. By way of example, such radio measurements consist in measuring an electric field at a certain frequency in order to evaluate the transmission quality of the antenna  3  at this particular frequency. 
         [0049]    The placing method then finally includes a step of modifying the position of the antenna support  1 ,  1 ′ on the edge  26  of the electric circuit card  2  in order to improve the parameter in question so that the system formed by the electric circuit card  2  and the antenna  3  operates in satisfactory manner. Optionally, the orientation of the antenna  3  may be modified by installing it in the other housing  11 ,  15  in order to improve said parameter. 
         [0050]    The placing method of the invention may be used during a test stage prior to designing the printed circuit of the electric circuit card, so as to define the final placing of the antenna relative to the card. 
         [0051]    The placing method of the invention may also be used during the method of fabricating an electric circuit card  2  of the invention. The fabrication method consists in making provision to freeze the position of the antenna  3  after the printed circuit of the electric circuit card  2  has been fabricated. The placing method of the invention thus begins with the steps of fabricating the printed circuit and mounting the electronic components  4  of the electric circuit card  2  on the printed circuit. The placing method then includes a step of placing the antenna  3  while using the placing method of the preceding claim. Once the best placing for the antenna  3  has been defined, the antenna support  1 ,  1 ′ is fastened to the electric circuit card  2  by making orifices  31  in the electric circuit card  2  in order to receive the fastener pegs  30  of the flexible tabs  29  of the antenna support  1 . 
         [0052]    It should be observed that these orifices  31  in this example are situated outside the boundary plane of the printed circuit of the electric circuit card  2 . Drilling these orifices  31  therefore does not damage the printed circuit and does not require additional qualification testing to be performed on the printed circuit. 
         [0053]    The invention is not limited to the particular embodiments described above, but on the contrary covers any variant coming within the ambit of the invention as defined by the claims. 
         [0054]    Although the antenna support as described has two housings, each adapted to receive the antenna, the invention applies to supports having some other number of housings. Likewise, provision may be made for a different number of flexible tabs, of conductor elements, of keying slots, of fastening positions, etc. The keying slots are optional. 
         [0055]    The invention also applies to an antenna of some other shape, when used in radio communication of any type (protocol, frequency, etc.). 
         [0056]    It should be observed that although the means for adjusting the position of the antenna on the card as described herein comprise a slideway enabling the position of the support and thus of the antenna on the card to be modified, the means for adjusting the position of the antenna could equally well be situated directly on the support. For example, the support could be provided with a device of the movable drawer type carried by the bottom portion of the support and receiving the antenna. In such a configuration, the support could then be mounted stationary relative to the electric circuit card, with the position of the antenna being modified by sliding the movable drawer on the support.