Abstract:
An apparatus  1  for detecting and evaluating objects in the vicinity of a vehicle, having transmitting and receiving means for electromagnetic radiation in the Gigahertz range, includes at least one antenna protected by a radome  11   a   , 11   b . The radome  11   a   , 11   b  is designed as lens-shaped in such a way that beam focusing and/or beam pivoting of the broadcast electromagnetic radiation is made possible.

Description:
CROSS-REFERENCE 
   The invention described and claimed hereinbelow is also described in PCT/DE 03/01855, filed Jun. 5, 2003 and DE 102 37 790.1, filed Aug. 17, 2002. This German Patent Application, whose subject matter is incorporated here by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119 ( a )–( d ). 
   BACKGROUND OF THE INVENTION 
   The invention relates to an apparatus for detecting and evaluating objects in the vicinity of a vehicle. 
   An apparatus for detecting and evaluating objects in the vicinity of a vehicle of this generic type is known from German Patent Disclosure DE 199 63 005 A1 of the present applicant. It includes a pulse radar sensor with transmitting and receiving means for transmitting and receiving electromagnetic waves in the Gigahertz range. The electromagnetic waves are broadcast and received by an antenna. Typically, to protect such antennas against harmful environmental factors, a so-called radome is provided. This coined term radome means a spherical protective dome. In the present application, the term radome is also used for protective means that are not spherical. 
   SUMMARY OF THE INVENTION 
   The invention offers the advantages in particular that because of the design of the radome, beam shaping and in particular beam propagation and/or pivoting are made possible. Beam propagation in a horizontal plane serves to broaden the detection range to an extent that could not be attained with a conventional radome. Beam pivoting makes easy adaptation to the body shape of the particular vehicle possible and thus offers greater flexibility in installing the apparatus. Hence most of the components of the apparatus can be identical parts that can be mass-produced in large numbers. The adaptation to the radiation characteristic required for a particular vehicle type is then by means of the radome designed according to the invention. The radomes can be connected to the apparatus by means of a clip connection, making installation especially easy. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     The apparatus of the invention will now be described in terms of the exemplary embodiments shown in the drawing. Shown are: 
       FIG. 1 , the apparatus with its essential component groups in an exploded view; 
       FIG. 2 , a cross section through the apparatus with a first exemplary embodiment of a radome; 
       FIG. 3 , a cross section through the apparatus with a second exemplary embodiment of a radome; 
       FIG. 4 , a cross section through the apparatus with a third exemplary embodiment of a radome; 
       FIG. 5 , a cross section through the apparatus with a fourth exemplary embodiment of a radome; and 
       FIG. 6 , a plan view on a striplike radome. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows the apparatus  1  with its essential component groups in an exploded view. The apparatus  1  includes a tublike housing  10 ,  15 , with a housing tub  10  and a cap  15 . The other component groups  11   a ,  11   b  and  12  are mounted in the housing tub, which is closed with the cap  15  after these component groups have been installed. Reference numerals  10   a  and  10   b  designate recesses in the bottom of the housing tub  10 . These recesses are designed in slotlike form and extend parallel to one another in opposed regions of the bottom of the housing tub  10 . The electromagnetic energy is broadcast through these slotlike recesses  10   a ,  10   b . Reference numerals  11   a ,  11   b  designate radomes. These radomes are designed essentially in striplike form and can be placed in the housing tub  10  in such a way that they cover the slotlike recesses  10   a , lob in the bottom of the housing tub. Thus they close off the housing  10 ,  15  from the outside in its bottom region and accordingly take over the usual protective function of a radome, which shields off vulnerable high-frequency components from harmful environmental factors. 
   Especially advantageously, the radomes  11   a ,  11   b  can be connected to the housing tub  10 , or to the further component groups  12 , by means of a clip connection. This makes installing the apparatus  1  substantially simpler and easier. 
   According to the invention, the radomes  11   a ,  11   b  are designed such that they not only perform the protective function known from conventional radomes but also effect beam shaping and/or beam deflection. This will be described below in terms of several exemplary embodiments.  FIGS. 2 ,  3 ,  4  and  5  each show a cross section through the apparatus  1  along a recess  10   a ,  10   b  in the bottom of the housing tub  10 . The exemplary embodiment shown in  FIG. 2  illustrates in principle how the radome  11   a , placed in the housing tub  10 , covers the recess  10   a  in the bottom of the housing tub  10  and thus closes off the housing  10 ,  15  from the environment. Especially advantageously, the radome  11   a  can be clipped onto carriers  21   a ,  21   b ,  21   c ,  21   d , which are connected to the printed circuit board  12 . In the process of installing the radome  11   a , to assure a defined installed position, the essentially striplike radome  11   a  can expediently also be provided with spacers  20   a ,  20   b , which preferably extend perpendicular to a main face of the radome  11   a . The radome  11   a  preferably comprises a material that is highly permeable to high-frequency radiation in the Gigahertz range yet is weatherproof, since in everyday operation of a vehicle it is exposed to severe environmental conditions. A thermoplastic, in particular PBT (polybutylene terephthalate) has proved especially highly suitable. To keep the damping of the electromagnetic waves by the loss-impeded material of the radome  11   a ,  11   b  as slight as possible, the thickness D of the radome  11   a ,  11   b  is reduced in the region of the recesses  10   a ,  10   b  as far as the mechanical stability and technical production capabilities allow. In practice, a thickness D of the radome  11   a ,  11   b  of between 0.2 mm and 15 mm can be considered. An especially favorable compromise in view of both a low damping value and still adequate mechanical stability is a thickness D of the radome  11   a ,  11   b  of 1.0 mm. As  FIG. 2  shows, for that purpose a recess is made in the outer surface of the radome  11   a ,  11   b  that reduces the thickness D of the radome in this region as desired. From a production standpoint, recesses that are rotationally symmetrical are especially simple, in which case the surface of the recess has the shape of a portion of a sphere or a spherical layer, for instance. However, arbitrary other structures of the recess can readily be attained from a production standpoint. Especially advantageously, the shaping of the recess serves the purpose of varying the beam, and in particular beam shaping and/or beam deflection of the broadcast electromagnetic energy. In an especially advantageous exemplary embodiment of the invention ( FIG. 4 ), the recess is designed cylinder-symmetrically; that is, the outer surface of the recess is part of a cylindrical jacket face. As a result of such a design, the radome  11   a ,  11   b  functions as a cylinder lens, which enables beam propagation in a horizontal plane. As a result, an especially favorable broadening of the detection range is made possible. 
   In a further exemplary embodiment ( FIG. 5 ), the recess has the shape of an asymmetrically embodied cylinder lens. As a result, beam deflection or beam pivoting can be attained in a simple way. In turn as a result, the radiation characteristic of the apparatus can be adapted especially simply to different body shapes of vehicles. In this way, great flexibility is obtained in terms of a favorable installation site for the apparatus. It is understood to be within the scope of the present invention to provide still other lens shapes in conjunction with the radome  11   a ,  11   b.    
   In an apparatus  1  that includes a plurality of antennas next to one another, a radome  11   a  which, as shown in  FIG. 6 , has a plurality of regions  60  that vary the electromagnetic radiation in the sense of beam focusing and/or deflection proves to be expedient.