Abstract:
An inventive measuring device comprises a measuring unit, a communication unit and a control unit. The measuring unit is adapted to wirelessly receive a measuring signal transmitted by a device under test. The control unit is adapted to derive at least one measuring device, especially a signal level, from the received measuring signal. The communication unit is adapted to only wirelessly transmit the at least one measuring result to a central measuring unit, not being part of the measuring device.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to a measuring device, a measuring system and a measuring method for measuring radiation patterns of devices under test, especially mobile telephones. 
       BACKGROUND ART 
       [0002]    For measuring the radiation pattern of mobile telephones, complex measurement set-ups are so far necessary. Within a shielded test chamber, one or more antennas are arranged around the device under test. While the device under test is radiating, the one or more antennas are moved with regard to the device under test so that measurements from all directions can be made. The individual measurement antennas are connected to a measuring device, which measures the received signals and processes them. The antennas are connected to the measuring device using cable connections. This results in scattering from the cable connections, which have to be suppressed or prevented so as not to influence the measurements. This is done by using absorbing material. Therefore, a very complex set-up due to the necessity of a measuring chamber and extensive shielding is required while at the same time due to the necessary movement of the measuring antennas, a long measuring time is necessary. 
         [0003]    The document US 2011/0084887 A1 shows a measuring set-up using a sphere of measuring antennas arranged around a device under test. Without the necessity of moving the measuring antennas with regard to the device under test, the measurements for all angles can be made within a short measuring time. The measuring set-up shown in this document though is also disadvantageous, since due to the cable connection of the individual measuring antennas, a great effort for absorbing and shielding is necessary. 
         [0004]    Accordingly, one object of the invention is to provide a measuring device, measuring system and measuring method, which allow for a very fast measurement of a large number of measurement angles while at the same time requiring only a low hardware effort. 
       SUMMARY OF THE INVENTION 
       [0005]    According to one aspect of the invention, the measuring device comprises a measuring unit, a communication unit and a control unit. The measuring unit is adapted to wirelessly receive a measuring signal transmitted by a device under test. The control unit is adapted to derive at least one measuring result, especially a signal level, from the received measuring signal. The communication unit is adapted to only wirelessly transmit the at least one measuring result to a central measuring unit, not being part of the measuring device. By arranging a plurality of such measuring devices around the device under test, it is thereby possible to simultaneously perform measurements for all measuring angles. Since the measuring results are transmitted wirelessly, a wired connection to the individual measuring devices is not necessary. Thereby, extensive absorbing and shielding measures are not necessary. 
         [0006]    Advantageously, the measuring device is adapted to be only wirelessly connected to any further units. Thereby, the need for extensive shielding can be further reduced. 
         [0007]    Preferably, the measuring device comprises a power supply unit adapted to only wirelessly received power. The measuring device is adapted to be exclusively powered by the wirelessly received energy. It is thereby possible to omit power transmission cables and thereby further reduce scattering. This allows for a very accurate measuring result while at the same time reducing the need of absorbing. 
         [0008]    Preferably, the power supply unit comprises an energy storage unit adapted to store the wirelessly received power. The power supply unit is adapted to power the measuring device exclusively from an energy stored in the energy storage unit. It is thereby possible to transmit power to the measuring device while no measurement is performed. While the measurement is actually performed, it is not necessary to continue transmitting power to the device under test. A further increase in measuring result quality can thereby be achieved. 
         [0009]    Preferably, the power supply unit comprises a power reception unit adapted to receive the wirelessly received power. The power reception unit is an RF-antenna or a solar cell or a magnetic resonator. The power reception unit is adapted to receive only ambient power from ambient light, ambient RF-radiation or ambient magnetic fields. Also an energy harvesting from a temperature difference is possible. This would be achieved by use of a Peltier element. Alternatively, the power reception unit is adapted to receive only wirelessly transmitted power from a central power unit. It is thereby possible to either harvest ambient energy without having to provide additional power. This reduces the hardware effort significantly. Alternatively, for higher power consumption measuring device, providing the power by a central power unit allows for a very effective measuring device. 
         [0010]    Preferably, the measuring unit comprises at least one strip line measuring antenna on a circuit board. The strip line measuring antenna is adapted to receive the measuring signal. A very low-cost and low-hardware-effort measuring set-up is thereby possible. 
         [0011]    Preferably, the measuring unit comprises a further strip line measuring antenna on a further circuit board. The measuring antenna and the further measuring antenna are arranged so that the received orthogonally polarized measuring signals. It is thereby possible to measure two different measuring signals for a single measuring angle regarding two different polarization planes. This further increase the measuring speed, since a second measuring process for the second polarization is not necessary. 
         [0012]    Preferably, all further units of the measuring device are mounted on the surface of the at least one circuit board. An especially low-cost hardware-setup is thereby possible. 
         [0013]    Further preferably, the communication unit comprises a transmission antenna for transmitting the at least one measurement result as an RF-signal to the central measuring unit. Alternatively, the communication unit comprises an LED for transmitting the at least one measurement result as a visible or infrared or ultraviolet light signal to the central measuring unit. A high flexibility of construction is thereby possible. 
         [0014]    According to another aspect of the invention, a measuring system comprises a plurality of before-described measuring devices, a central measuring unit, and a device under test mount adapted for holding the device under test. The measuring devices are arranged around the device under test mount. The communication units of the plurality of measuring devices are adapted to transmit the measuring results to the central measuring unit, while the central measuring unit is adapted to receive the measuring results from the plurality of measuring devices. A very low-cost and low-hardware-effort measuring set-up is thereby possible. 
         [0015]    Preferably, the measuring devices are arranged in a circular or spherical pattern around the device under test mount. The measuring devices are adapted to each generate and transmit a measuring result for a single position regarding the device under test. The measuring devices are arranged so that measuring results for a plurality of positions are obtained by the central measuring unit. It is thereby possible to perform all measurements for a single device under test without the need to move the device under test or the measuring devices, in case of a spherical arrangement. In case of a circular arrangement, only a rotation of the device under test is necessary. This results in a very short measuring time. 
         [0016]    Preferably, the measuring system comprises a central power unit adapted to wirelessly transmit power to the measuring devices. The central power unit comprises a lamp for transmitting power in the form of visible light or infrared light or ultraviolet light to the measuring devices. Alternatively, the central power unit comprises an RF-antenna for transmitting power in the form of RF-radiation to the measuring devices. In a further alternative, the central power unit comprises a magnetic resonator for transmitting power in the form of a magnetic field to the measuring devices. It is thereby possible to very flexibly construct the measuring system and keep the hardware effort to a minimum. 
         [0017]    According to still another aspect of the invention, the measuring method serves the purpose of deriving a plurality of measurement results from a plurality of angles around a device under test. The method comprises transmitting a measuring signal by the device under test, receiving the measuring signal by a plurality of measuring devices arranged in a pattern around the device under test, deriving at least one measuring result from each received measuring signal by the plurality of measuring devices, and wirelessly transmitting the measuring results to a central measuring unit. It is thereby possible to measure all measurement angles for a device under test in one measurement process without having to move the device under test or the respective measuring devices. Also, a very low-hardware-effort can be achieved, since by wirelessly transmitting the measuring results, cable connections from the measuring devices to the central measuring unit are not necessary. Thereby, extensive absorbing and shielding is not necessary. 
         [0018]    Preferably, the measuring devices are provided with power exclusively wirelessly. Thereby, power transmission cables can also be omitted, which leads to very low absorbing and shielding requirements. 
         [0019]    Preferably, the position and orientation of the device under test and the measuring devices is not changed during a complete measuring process. A further reduction in measuring time is thereby possible. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    An exemplary embodiment of the invention is now further explained by way of example only with respect to the drawings, in which 
           [0021]      FIG. 1  shows an overview of an embodiment of the inventive measuring system; 
           [0022]      FIG. 2  shows a block diagram of a first embodiment of the inventive measuring device; 
           [0023]      FIG. 3  shows a detailed block diagram of an aspect of the embodiment of the inventive measuring system; 
           [0024]      FIG. 4  shows a detailed block diagram of a further aspect of the embodiment of the inventive measuring system; 
           [0025]      FIG. 5  shows a second embodiment of the inventive measuring device; 
           [0026]      FIG. 6  shows a third embodiment of the inventive measuring device, and 
           [0027]      FIG. 7  shows an embodiment of the inventive measuring method in a flow diagram. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    Firstly, we demonstrate the general set-up and construction of an embodiment of the inventive measuring system along  FIG. 1 . Along  FIG. 2 , the detailed construction and function of an embodiment of the inventive measuring device is described. With use of  FIGS. 3 and 4 , further aspects of the embodiment of the inventive measuring system are described in detail. Along  FIGS. 5 and 6 , alternative embodiments of the inventive measuring device are shown. Finally, with regard to  FIG. 7 , the function of an embodiment of the inventive measuring method is described in detail. Similar entities and reference numbers and different figures have been partially omitted. 
         [0029]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. However, the following embodiments of the present invention may be variously modified and the range of the present invention is not limited by the following embodiments. 
       First Embodiment 
       [0030]    In  FIG. 1 , an embodiment of the inventive measuring system  2  is shown. The measuring system  2  comprises a device under test mount  18 , for holding a device under test  1 . Surrounding the device under test mount  18 , a plurality of measuring devices  10 - 17  is arranged. In this example, the measuring devices  10 - 17  are arranged in a circular pattern around the device under test mount  18 . Alternatively, they can be arranged in a cylindrical or spherical pattern. Any pattern, which allows a simultaneous measurement of all necessary measurement angles is possible. 
         [0031]    The measurement system  2  furthermore comprises a central unit  3  comprising a central measuring unit  4  and a central power unit  5 . The central measuring unit  4  and the central power unit  5  are optionally connected by a wired or wireless interface. The central power unit  5  transmits power wirelessly to the measuring devices  10 - 17 . In this example, the central power unit  5  transmits power in the form of RF-signals using an RF-antenna. The individual measuring devices  10 - 17  each comprise a power supply unit for receiving the wirelessly transmitted power and powering the respective measuring device  10 - 17 . Details of the construction of the individual measuring devices  10 - 17  are given with regard to  FIG. 2 . 
         [0032]    Moreover, the central measuring unit  4  wirelessly receives measuring results of the individual measuring devices  10 - 17 . In this example, the measuring results are transmitted as RF-signals wirelessly and received by use of an RF-antenna by the central measuring unit  4 . 
         [0033]    Since the individual measuring devices  10 - 17  do not require any wired connections to the central unit  3  or any other unit, extensive absorbing and shielding measures to prevent field scattering from such wired connections are not necessary. If scattering from any surrounding objects are negligible, not even a shielded anechoic chamber is necessary. 
       Second Embodiment 
       [0034]    In  FIG. 2 , a first embodiment of the inventive measuring device  10  is shown. All measuring devices  10 - 17  of  FIG. 1  are constructed identically. 
         [0035]    The measuring device  10  comprises a control unit  20 , a power supply unit  21 , a measuring unit  22  and a communication unit  23 . The power supply unit  21  comprises an energy storage unit  24 , a power processing unit  21   a  and power reception unit  21   b . The energy storage unit  24  only is an optional component. In case it is present, it is connected to the control unit  20  and to the power processing unit  21   a . The power reception unit  21   b  is connected to the power processing unit  21   a . The measuring unit  22  comprises a measuring antenna  22   b  and a measuring processing unit  22   a . The measuring processing unit  22   a  is connected to the control unit  20  and to the measuring antenna  22   b . The communication unit  23  comprises a data transmission unit  23   a , which is connected to the control unit  20  and a transmission antenna  23   b.    
         [0036]    By use of the power supply unit  21 , the measuring device  10  receives wirelessly transmitted power. The power reception unit  21   b , for example an RF-antenna, or a magnetic resonator or a solar cell or a Peltier element receives the wirelessly transmitted power, either ambient power or deliberately transmitted power and hands it to the power processing unit  21   a . The power processing unit  21   a  brings the wirelessly received power into a usable form and optionally stores it in the energy storage unit  24 , in case such a unit is present. Alternatively, if such a unit is not present, the power processing unit  21   a  directly powers the measuring device  10  through a connection to the control unit  20 . 
         [0037]    If an energy storage unit  24  is present, it is not necessary to receive wireless power during performing measurements. It is then possible to charge the energy storage unit  24  before performing the measurements and then refrain from receiving more power during measurements. An increase in measuring accuracy can thereby be reached. 
         [0038]    While performing measurements, the measuring antenna  22   b  receives measuring signals from the device under test  1  as shown in  FIG. 1 . The received measuring signals are handed to the measuring processing unit  22   a , which derives measuring results from the received measuring signals. These measuring results are handed on to the control unit  20 , which hands them on to the data transmission unit  23   a , which transmits the measuring results by use of the transmission antenna  23   b . Instead of a transmission antenna  23   b  as depicted here, alternatively also a transmission using visible light signals or infrared light signals or ultraviolet light signals and for example an LED for generating these signals is possible. 
       Third Embodiment 
       [0039]    In  FIG. 3 , a detail of the measuring system  2  of  FIG. 1  is shown. Here, the central measuring unit  4  is depicted in greater detail. The central measuring unit  4  comprises a control unit  30  and a data reception unit  31 , which is connected to the control unit  30 . Moreover, it comprises a data reception antenna  32 , which is adapted to receive the wirelessly transmitted measuring results from the measuring devices  10 - 17  of  FIG. 1  and  FIG. 2 . The central measuring unit  4  furthermore comprises a data storage unit  34 , which is connected to the control unit  30 . Also it comprises a display unit  33 , which is also connected to the control unit  30 . The received measuring results are processed by the control unit  30  and stored by the data storage unit  34 . 
         [0040]    The display unit is adapted to display the received measuring results. 
         [0041]    Alternatively, also a receiver for visible light communication or ultraviolet or infrared light communication can be integrated instead of the antenna  32 , in case the measuring results are transmitted in this fashion by the measuring devices  10 - 17 . The control unit  30  moreover comprises an optional interface  6  for connecting it to a central power unit  5  as depicted in  FIGS. 1 and 4 . 
       Fourth Embodiment 
       [0042]    In  FIG. 4 , a further detail of the inventive measuring system  2  of  FIG. 1  is shown. Here, the central power unit  5  is depicted in greater detail. The central power unit  5  comprises a control unit  40 , which is connected to a power transmission unit  41 , which again is connected to a power transmission antenna  42 . Controlled by the control unit  40 , the power transmission unit  41  generates a power transmission signal, which is transmitted by the power transmission antenna  42  and used to wirelessly power the measuring devices  10 - 17  of  FIGS. 1 and 2 . The control unit  40  optionally comprises an interface  6  for a connection to a central measuring unit  4  as depicted in  FIGS. 1 and 3 . Instead of a power transmission antenna, also a lamp or a magnetic resonator can be used for transmitting power. 
         [0043]    Alternatively to the construction shown in  FIG. 1  of having a separate central measuring unit and central power unit, these components can also be integrated into a single device. This is indicated by the dashed line and the reference number  3  for a central unit  3 . 
       Fifth Embodiment 
       [0044]    In  FIG. 5 , a further embodiment of the inventive measuring device  10  is shown. Also here it is important to note, that all measuring devices  10 - 17  of  FIG. 1  are identical and can be manufactured in the fashion as depicted here. In  FIG. 5 , the measuring device  10  comprises a measuring antenna  22   b , which is comprised of conductive surfaces  51 ,  52  on a circuit board  50 . In addition to the measurement antenna  22   b , at least some further components, advantageously all further components of the measuring device  10  are mounted on the circuit board  50 . Here, on the surface of the circuit board  50 , the power processing unit  21   a , the power reception unit  21   b , the measuring processing unit  22   a , the data processing unit  23   a  and the data transmission antenna  23   b  are arranged. It is thereby possible to construct the measuring device  10  with a very low labor and material effort. Also a very small footprint is achieved. 
       Sixth Embodiment 
       [0045]    In  FIG. 6 , a further embodiment of the measuring device  10  is shown. Also here, it is important to note, that all measuring devices  10 - 17  can be manufactured in this matter. The measuring device  10  of  FIG. 6  shows two cross-polarized measuring antennas  61 ,  62 , each comprising its own measuring unit. These are not displayed here, though. Therefore the setup of  FIG. 6  integrates the measuring cross-polarized signals at a single location into one measuring unit  10 . The cross-polarized measuring antennas  61 ,  62  are mounted on a perpendicular circuit board  60 . The circuit board  60  though is not necessary for the present invention. By use of this construction, it is possible to receive two different polarization planes of signals emitted by the device under test simultaneously. 
       Seventh Embodiment 
       [0046]    In  FIG. 7 , an embodiment of the inventive measuring method is shown by use of a flow diagram. In a first step  100 ,  3   o  the device under test is placed on a device under test mount. The device under test mount can also be the hand of an operator holding the device under test. In a second step  101 , power is transferred wirelessly to the measuring devices. This can be ambient energy or power deliberately transmitted by a power supply unit. In a third step  102 , the power is received by the individual measuring devices. The measuring devices are powered by this received power. In a fourth step, a measuring signal transmission by the device under test is initiated. In a fifth step  104 , the measuring signal is received by the measuring devices. In a sixth step  105 , the measuring signal is processed by the measuring devices resulting in measuring results. In a seventh step  106 , the measuring results are transmitted wirelessly by the measuring devices to a central unit. In an eighth step  107 , measuring results are received by the central unit. In a ninth and final step  108 , the received measuring results are processed by the central unit. Optionally, the can be displayed by the central unit. 
         [0047]    The embodiments of the present invention can be implemented by hardware, software, or any combination thereof. Various embodiments of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or the like. 
         [0048]    Various embodiments of the present invention may also be implemented in the form of software modules, processes, functions, or the like which perform the features or operations described above. Software code can be stored in a memory unit so that it can be executed by a processor. The memory unit may be located inside or outside the processor and can communicate date with the processor through a variety of known means. 
         [0049]    The invention is not limited to the examples. The characteristics of the exemplary embodiments can be used in any combination. 
         [0050]    Although the present invention and its advantages have been described in detail, it should be understood, that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.