Abstract:
A satellite antenna station composed of: a dish for concentrating received electromagnetic energy; photovoltaic elements for supplying electric power to the station; and a positioning device controlled by a control unit. The positioning device is adjustable at least into a first position for optimizing reception of a signal from a satellite and into a second position for optimizing exposure of the photovoltaic elements to solar radiation.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Satellite reception units consisting of a satellite antenna and corresponding receiver equipment are increasingly being used also for mobile applications, e.g., on vehicles such as motor homes. Each time such a unit is moved, which occurs frequently, it is necessary to optimally re-aim the generally small satellite antenna toward the satellite being received. In addition, at many locations there often is no line power supply available for the operation of the satellite reception unit.  
         [0002]     DE 198 34 577 A1 discloses a special satellite antenna, consisting of many small individual antennas, that is dimensioned for motor homes. With the aid of GPS, the entire system can be swiveled by mechanical rotation into the desired direction for reception.  
         [0003]     The problem of power supply availability is not addressed in this prior art.  
         [0004]     DE 42 08 101 A discloses a stationary satellite reception unit, the parabolic reflector of which is designed not only for the usual purpose of bundling the incident rays onto the focal point, but in which the parabolic mirror additionally has a photovoltaic element affixed on it that directs the daylight, which impinges with greater or lesser intensity in the given satellite reception position of the reflector, to a battery that stores the electric energy to use it for the power supply to the satellite antenna and its associated reception components.  
         [0005]     This solution has the shortcoming that the photovoltaic element on the reflector side may possibly impact the reception qualities for the satellite signal. The inevitable orientation of the satellite antenna toward the satellite accordingly has as a consequence that an optimization of the power supply generated by the photovoltaic element is not possible but occurs only as a by-product.  
         [0006]     In the case of the receiving and reflector surfaces in mobile satellite reception units, which are generally made as small as possible, the solution according to this prior art does not have any advantages.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     The invention serves to optimize the basic concept of a dual purpose of a satellite antenna both for feeding a received satellite signal in the corresponding receiving equipment, as well as for producing solar energy, in such a way that an application to satellite antennas with small dimensions, especially for mobile applications, is made possible as well.  
         [0008]     For this purpose, the invention provides a satellite antenna station comprising: a dish for concentrating received electromagnetic energy; photovoltaic elements for supplying electric power to the station; and a positioning device controlled by a control unit, wherein the positioning device is adjustable for moving the dish at least into a first position for optimizing reception of a signal from a satellite and into a second position for optimizing exposure of the photovoltaic elements to solar radiation.  
         [0009]     The basic concept of the invention can thus be seen in the fact that the generally unutilized rear of the satellite antenna carries the photovoltaic elements and the adjustability of the reflector, primarily used to maximize the received signal, which is generally already provided in modern satellite reception units, is used to also attain a 2-axis optimization of the solar energy made available by the sun or daylight.  
         [0010]     According to a preferred embodiment, the positioning device may cooperate with a navigation receiver (e.g., GPS), the location data from which can be utilized both for the adjustment of the satellite reception position, as well as for the adjustment of the solar ray reception position, and which thus also experiences a dual use. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     A preferred embodiment of the invention will now be explained in more detail with reference to the drawings, in which:  
         [0012]      FIGS. 1A and 1B  are front and rear views of a satellite antenna station according to the invention;  
         [0013]      FIG. 2  is a side view of the satellite antenna station in a storage position;  
         [0014]      FIG. 3  is a first perspective view of the satellite antenna station in a first position for receiving a satellite signal;  
         [0015]      FIG. 4  is a second perspective view of the satellite antenna station in a second position for generating solar power; and  
         [0016]      FIG. 5  is a block diagram of a system for controlling the position of the station. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]     Referring to  FIGS. 1-5  a satellite antenna station according to the invention has a conventional parabolic or planar dish, or antenna  10 . The reverse side of antenna  10 , the side facing away from the signal reflecting side, is provided with a plurality of photovoltaic elements that form a solar module  10 A. The front side of antenna  10  is provided with a reflecting surface or reflector  10 B for reflecting satellite signals to a signal receiver or detector.  
         [0018]     Antenna  10  is secured, at its front side, to the upper end  31 A of a yoke  31 .  
         [0019]     The lower end  31 B of yoke  31  is mounted to pivot about a horizontal swivelling axis H-H through a swivel angle, or elevation angle, β on a rotation unit  32  that is itself rotatable about a vertical axis V-V.  
         [0020]     Rotation unit  32  is implemented as a base element, which can be attached, for example, to the roof of a structure such as a motor home.  
         [0021]     By rotation of rotation unit  32  through a certain angle of rotation, or azimuth angle, a about the vertical axis V-V and swiveling of yoke  31  through a certain swivel angle β about the horizontal axis H-H, any orientation of the antenna toward a certain point in the sky is possible.  
         [0022]     In  FIG. 2 , the satellite antenna is shown in its idle, or storage position, in which it is folded down with the reflector side  10 B and the solar module  10 A is facing up, i.e., the satellite antenna is located in a horizontal position in which at least a generation of solar power by means of the photovoltaic elements of the solar module  10 A is possible in dependence upon the position of the sun.  
         [0023]      FIG. 3  shows the inventive embodiment for adjusting the satellite antenna in the direction X-X in such a way that the signal transmitted by a geostationary satellite S impinges upon the reactor surface  10 B in such a way that an optimization in the sense of a maximization of the received signal occurs. This first position (satellite mode) is thus characterized by a certain value β1 of the swivel angle about the horizontal axis H-H and the angle of rotation α1 about the vertical axis V-V.  
         [0024]     In the position shown in  FIG. 4 , the solar module  10 A is aimed in the direction Y-Y toward the sun, so that this second position (solar mode) is characterized by an appropriately selected swivel movement by a certain swivelling angle β2 about the horizontal axis H-H and a rotation by a certain angle of rotation α2 about the vertical axis V-V.  
         [0025]     The adjustment to either of the first and second positions may advantageously take place in such a way that, as shown in  FIG. 5 , movement of yoke  31  and rotation unit  32  is controlled by an associated control unit  41  that receives, from a navigation receiver  42 , data identifying the exact location of the station. With this location data as a starting point, the angles α1/β1 for the first position in the satellite mode, i.e., the orientation toward the satellite S that is associated with a desired TV station, may be computed with the use of appropriate tables or calibration values, and by selection of the angles α2/β2 the second position in the solar mode, and by means of appropriate control signals to the rotation unit  32 , the same may be rotated about the vertical axis V-V to the computed target angle α1/α2, and the satellite antenna  10  may be swiveled by an appropriate swiveling of the yoke  31  about the horizontal axis H-H to the computed target angle β1/β2.  
         [0026]     The corresponding motors for this control system are not shown in the drawings. These motors and the hardware and software needed to properly orient antenna  10  are already well known in the art.  
         [0027]     Based on the position data supplied by the navigation receiver, it is easily possible to perform an automatic change in position from one satellite to another (multiple positions in the satellite mode) with suitable formulas in the software of the receiver electronics.  
         [0028]     In the second position (solar mode), an automatic tracking of the sun by the satellite antenna, for example in minute-steps, can be performed with the aid of appropriate tables or calibration values, wherein special sun or brightness sensors are no longer necessary due to the fact that the navigation receiver is used for this purpose as well.  
         [0029]     Particularly advantageous in the inventive conception is the fact that the usage periods of the satellite mode and solar mode, which largely correspond to the time of day, overlap only to a small extent, so that a very economic overall solution in the sense of a continuous use of the satellite antenna has been found in this respect as well.  
         [0030]     This application relates to subject matter disclosed in German Application Number 203 14 930.0, filed on Sep. 26, 2003, the disclosure of which is incorporated herein by reference.  
         [0031]     The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.  
         [0032]     Thus the expressions “means to . . . ” and “means for . . . ”, or any method step language, as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i.e., other means or steps for carrying out the same functions can be used; and it is intended that such expressions be given their broadest interpretation.