Testing arrangement and method for determining an optimized distance between a device under test and an antenna of a testing arrangement

Abstract

A method and a testing arrangement for determining an optimized distance between a device under test and an antenna of a testing arrangement are presented. The method comprises obtaining first measurement data, wherein the first measurement data represent a plurality of far field measurement results characterizing the device under test for a set of frequencies, or wherein the first measurement data are based on a plurality of far field measurement results characterizing the device under test for a set of frequencies, obtaining second measurement data, wherein the second measurement data represent a plurality of near field measurement results characterizing the device under test for the set of frequencies, or wherein the second measurement data are based on a plurality of near field measurement results characterizing the device under test for the set of frequencies; wherein at least two of the near field measurement results are captured at different distances between the device under test and an antenna of the testing arrangement; and determining the optimized distance between the device under test and the antenna of the testing arrangement based on the first and second measurement data.

Description

[0001] Testing arrangement and method for determining an optimized distance between a device under test and an antenna of a testing arrangement

[0002] Technical field

[0003] Embodiments according to the invention relate to a testing arrangement and method for determining an optimized distance between a device under test and an antenna of a testing arrangement, in particular using near field and far field measurement data.

[0004] Embodiments according to the invention relate to a procedure and algorithm to define an optimal (or optimized) distance between a device under test (DUT) and a measurement antenna on an over the air (OTA) Socket.

[0005] Background of the invention

[0006] With advancement in wireless communication and increasing use of wireless devices, devices that emit and / or receive electromagnetic fields needs to be tested accurately and efficiently. An electromagnetic field of a device under test comprises a near field and a far field. The near field of devices under test can be affected by many factors such as resonance effects, emitted and / or received wavelengths, a design of an antenna structure, and materials (e.g., metal) of a testing arrangement. As a result, testing of a near field may significantly depend on a distance of the device under test and an antenna of the testing arrangement. Determining an optimized distance from simulations requires factoring in many parameters and can be time consuming.

[0007] Therefore, there is a need for a testing arrangement that improves a compromise between testing accuracy, testing complexity, and testing efficiency.

[0008] Summary of the invention

[0009] An embodiment of the invention is directed to a method for determining an optimized (e.g. well-useable or even optimal or ideal) distance between a device under test (e.g., an An- tenna-in-Package)) and an antenna of a testing arrangement, the method comprising obtaining first measurement data (e.g. reference far field data), wherein the first measurement data represent a plurality of far field measurement results (e.g. power measurement results and / or gain measurement results and / or gain step measurement results and / or gain compression measurement results and / or phase shift measurement results and / or flatness measurement results and / or error vector magnitude measurement results and / or isolation measurement results and / or spurious emission measurement results and / or adjacent channel power ratio measurement results and / or IP3 measurement results and / or noise figure measurement results) (e.g., based on a measurement at a distance between the device under test and a measurement antenna that is larger than the Fraunhofer distance (dF=2D2 / A wherein D is a largest dimension of a radiator or a diameter of a sphere enclosing the radiator or the antenna, and wherein A is a used wavelength, e.g. a smallest used wavelength or a largest used wavelength or an average used wavelength or a wavelength at an average used frequency); e.g. larger than 10mm) characterizing the device under test for a set of frequencies (e.g. for a plurality of frequencies) (e.g., comprising ten, eleven, or twelve frequencies) (e.g., in a frequency range of 24GHz to 53GHz), or wherein the first measurement data are based on a plurality of far field measurement results characterizing the device under test for a set of frequencies. The method further comprises obtaining second measurement data (e.g. measurement data for different distances x, for which near field conditions between the device under test and the antenna of the testing arrangement apply) (e.g., generated by the antenna of a testing device), wherein the second measurement data represent a plurality of near field measurement results (e.g. a plurality of sets of near field measurement results associated with different distances) (e.g., measured at distances between the device under test and an antenna of the measurement arrangement which is within the “Fraunhofer distance”) characterizing the device under test for the set of frequencies (wherein the antenna of the measurement arrangement which is used to obtain the near field measurement results may be different from the measurement antenna used to obtain the far field measurement results or may be equal to the measurement antenna used to obtain the far field measurement results), or wherein the second measurement data are based on a plurality of near field measurement results (or a plurality of sets of near field measurement results associated with different distances) (e.g., measured at distances between the device under test and an antenna of the measurement arrangement which is within the “Fraunhofer distance”) characterizing the device under test for the set of frequencies. At least two of the near field measurement results (or at least two sets of near field measurement results) are captured at different distances (in step increments of 1 mm) (in a range of 20mm to 40mm) between the device under test and an antenna of the testing arrangement (wherein the antenna of the testing arrangement may be identical to the measurement antenna used to obtain the far field measurement results or may be different from the antenna used to obtain the far field measurement results). The method comprises determining the optimized distance between the device under test and the antenna of the testing arrangement based on the first and second measurement data (e.g. based on a comparison between the first and second measurement data)(e.g. taking into consideration measurement data at different frequencies).

[0010] It has been recognized that the first measurement data provides measurement data that are obtained from far field measurements and therefore are less affected factors that cause measurements to be so dependent on a distance between the device under test and the antenna of the testing arrangement. For example, resonance effects are less pronounced such that first measurement data provide a less distorted reference for the device under test. It has been recognized that resonance effects are linked to the wavelength of the near field. Therefore, obtaining first measurement data representing or based on a set of frequencies provides a reference that allows covering more frequencies and therefore increases the chance of determining an optimal distance less affected by resonance effects. The second measurement data is obtained from the near field for the set of frequencies, wherein the set of frequencies can be used as a common link between the first and second measurement results, that allow the reference of the far field measurements to be compared to the second measurement data that is representing or based on near field measurements. It has been recognized that if at least two near field measurement results are captured at different distances between the device under test and an antenna of the testing arrangement, for each distance, a comparable first and second measurement data for the frequency sets can be realized. In this way, the reference of the far field measurements allows determining an optimized distance from the two (or more) distances for near field measurements.

[0011] Since the optimized distance can be determined from measurements of the testing arrangement instead of other means such as simulations, the optimized distance can be determined without having to consider potential external factors that may have influenced the near field measurement. The method therefore reduces or eliminates the need for complex and resource intensive simulations of a standing wave effect in order to define an optimized distance between the device under test (e.g., AiP DUT antenna array) and the OTA measurement antenna. The method is less dependent on the testing arrangement and can therefore be implemented in different types and models of a testing arrangement. As a result, the test can be performed by different users (e.g., having a different or new testing arrangement) and without having to determine apparatus specific properties that may influence the near field. Testing in the near field allows for a more compact testing arrangement and facilitates low-cost and / or high-volume over the air (OTA) multi-site testing. Since the testing arrangement itself can perform the measurements, the method may be performed with many already existing testing arrangements or may be implemented by adding a testing device (e.g., comprising a stage supporting the antenna) to a testing arrangement. Specific handler model that may be used in high volume production testing measure at low distances (e.g., less than 40 mm or less than 30 mm depending on the specific handler model used in high volume production testing), can be used more reliably in the optimized distance of, which facilitates high volume production testing. At such short distances a user may have, for example, an antenna array transmitting at a certain frequency and on top of it a measurement antenna with metal components receiving (or vice-versa). In this situation for a certain distances between, for example, an antenna in package device under test (AiP DUT) antenna (array) and the measurement antenna, for example, a resonant wave may be present that reduces the measured power at those frequencies. By determining an optimized distance, standing waves may be reduced or avoided with tests using, for example, such metal components and frequencies. The method is compatible with high frequencies such as the 5G frequency bands, and can therefore improve testing for new 5G compatible devices.

[0012] The present disclosure proposes, for example, a method (e.g., a procedure and / or algorithm) for determining or finding an ideal or optimized distance between, for example, an antenna in package antenna array and a measurement antenna in, for example, a radiating near-field socket for over the air (OTA) testing with an automated testing equipment (ATE). Such an ideal or optimized distance depends, for example, on characteristics of an AiP antenna array of a (measurement) antenna and, for example, on a test program especially the specific frequencies to be tested. The present disclosure may be implemented, for example, as a hardware setup (e.g., a testing arrangement or a testing device thereof) and an algorithm to automatically find this optimized distance. The method (e.g., procedure / algo- rithm) is, for example, one of the critical parts for a successful design and implementation of a radiating near-field socket (e.g., device socket) or change kit (e.g., testing device), for example, for low-cost high-volume over the air (OTA) multi-site testing. This procedure or method can be, for example, ATE platform independent. The method may be implemented, for example, to perform a measurement with an entire application setup including the device under test (e.g., DUT AiP, OTA measurement antenna) and a test program (e.g., a target test program (e.g., with its multiple testing frequencies)), for example, to automatically identify, for example, an optimized AiP DUT antenna array to OTA measurement antenna distance, for example, inside a maximum limit set by the handler mechanics. According to an embodiment, determining the optimized distance comprises comparing one or more values of the second measurement data (e.g. a first set of values) obtained for a first distance between the device under test and the antenna of the measurement arrangement or associated with a first distance between the device under test and the antenna of the measurement arrangement (e.g. measurement data associated with different frequencies) with one or more corresponding values of the first measurement data (e.g. a set of far field measurement data associated with different frequencies), to obtain a first comparison result (e.g. a correlation value describing a similarity between the second measurement data obtained for the first distance and the first measurement data); and comparing one or more values of the second measurement data (e.g. a second set of values) obtained for a second distance between the device under test and the antenna of the measurement arrangement or associated with a second distance between the device under test and the antenna of the measurement arrangement (e.g. measurement data associated with different frequencies) with one or more corresponding values of the first measurement data (e.g. a set of far field measurement data associated with different frequencies), to obtain a second comparison result (e.g. a correlation value describing a similarity between the second measurement data obtained for the second distance and the first measurement data); and determining the optimized distance on the basis of the first comparison result and the second comparison result (e.g. comparing (e.g., forming a scalar difference or forming a difference vector and determining a norm or the difference vector, or determining a correlation), for each distance (and optionally for each frequency), one or more values of the first measurement data or one or more values derived from the first measurement data with one or more values of the second measurement data or one or more values derived from the second measurement data).

[0013] The method therefore in allows improving testing parameters related to a reception of the device under test. The first comparison result allows assessing a quality of the near field measurement results at the first distance by using the far field measurement as a comparison reference. As a result, the first comparison result has information that allows determining how far the near field measurement at the first distance deviates from the far field measurement. Similarly, the second comparison result has information that allows determining how far the near field measurement at the second distance deviates from the far field measurement. Since the first and second measurements are associated with the first and second distances, the first and second comparison results allow determining which one of the first and second distances shows less deviation from the reference and is therefore better suited as an optimized distance. The optimized distance thus determined allows avoiding or reducing resonance effects.

[0014] According to an embodiment, the first and second measurement data, or at least one or more values of the first and second measurement data, are obtained based on a wireless transmission of a signal by the device under test or are obtained when the device under test is wirelessly transmitting a signal (e.g., to the testing arrangement or another testing arrangement for the first and / or second measurements; e.g. to the antenna of the testing device).

[0015] The method therefore is able to determine the optimized distance based on transmission properties of the device under test. The method can be performed based on first and second measurement data based on wireless transmission. Therefore, the method does not require measurements that are performed during the method but can be performed based on far field measurement results that have been measured at a point in the past (e.g., on the same testing arrangement or a further testing arrangement). However, the method may be used directly during (or shortly after) the measurements for the first and / or second measurement data are performed.

[0016] According to an embodiment, the one or more values of the first measurement data comprise at least one of a power value (e.g. in milliwatts or dBm; e.g. determined using an evaluation of a signal received at the antenna of the measurement arrangement), a gain value (e.g., in units of decibel; e.g. determined using an evaluation of a signal received by the antenna of the measurement arrangement), a gain step value (e.g., in units of decibel; e.g. determined using an evaluation of a signal received by the antenna of the measurement arrangement), a gain compression value (e.g., 1 dB compression point (P1 db); e.g. determined using an evaluation of a signal received by the antenna of the measurement arrangement), a phase shift value (e.g., in units of degrees, e.g., phase shift during beamforming; e.g. determined using an evaluation of a signal received by the antenna of the measurement arrangement), a gain flatness value (e.g. determined using an evaluation of a signal received by the antenna of the measurement arrangement), an error vector magnitude value (e.g., in units of dBc; e.g. determined using an evaluation of a signal received by the antenna of the measurement arrangement), an isolation value (e.g., degree of isolation between different directions of polarization; e.g. determined using an evaluation of one or more signals received by the antenna of the measurement arrangement), a spurs value (e.g. indicating spurious emissions; e.g. determined using an evaluation of a signal received by the antenna of the measurement arrangement), and an adjacent channel power ratio value (e.g. determined using an evaluation of a signal received by the antenna of the measurement arrangement), wherein the one or more values of the second measurement data comprise at least one of a power value (e.g. in milliwatts or dBm), a gain value (e.g., in units of decibel), a gain step value (e.g., in units of decibel), a gain compression value (e.g., 1 dB compression point (P1 db)), a phase shift value (e.g., in units of degrees, e.g., phase shift during beamforming), a gain flatness value, an error vector magnitude value (e.g., in units of dBc), an isolation value (e.g., degree of isolation between different directions of polarization), a spurs value (e.g. indicating spurious emissions), and an adjacent channel power ratio value (or any other metric measurable using an antenna).

[0017] These values may reflect resonance effects and therefore may form a basis for determining the optimized distance for a transmission of the device under test. The method is therefore compatible with a plurality of measurable parameters. Furthermore, since resonance effects may be reflected in a deviation of more than one measurable parameter, the optimized distance may be determined by measurements of one parameter (e.g., a parameter that is strongly affected by resonance effects and / or a parameter that the testing arrangement can measure at a high accuracy) and then use the optimized distance to measure a different parameter in further testing.

[0018] According to an embodiment, the first and second measurement data, or at least one or more values of the first and second measurement data, are obtained based on a wireless reception of a signal by the device under test, or are obtained when the device under test is wirelessly receiving a signal (e.g., from the testing arrangement or another testing arrangement for the first and / or second measurements; e.g. from the antenna of the testing arrangement).

[0019] The first and second measurement data can therefore be obtained during the method or before the method is performed. Since the values are measured by the testing arrangement, the optimized distance determined form these values is well suitable for future measurements of said values. According to an embodiment, the one or more values of the first measurement data comprise at least one of a power value (e.g. in milliwatts or dBm; e.g. measured by the device under test or by a test equipment connected to the device under test), a gain value (e.g., in units of decibel e.g. measured by the device under test or by a test equipment connected to the device under test), a gain step value (e.g., in units of decibel; e.g. measured by the device under test or by a test equipment connected to the device under test), a third-order intercept point value (e.g., in units of dBm; e.g. measured by the device under test or by a test equipment connected to the device under test), a phase shift value (e.g., in units of degrees, e.g., phase shift during beamforming; e.g. measured by the device under test or by a test equipment connected to the device under test), a gain flatness value (e.g., in units of decibel; e.g. measured by the device under test or by a test equipment connected to the device under test), an error vector magnitude value (e.g., in units of dBc; e.g. measured by the device under test or by a test equipment connected to the device under test), an isolation value (e.g., degree of isolation between different directions of polarization; e.g. measured by the device under test or by a test equipment connected to the device under test), and a noise figure value (e.g. measured by the device under test or by a test equipment connected to the device under test), and wherein the one or more values of the second measurement data comprise at least one of a power value (e.g. in milliwatts or dBm), a gain value (e.g., in units of decibel), a third-order intercept point value, a phase shift value (e.g., in units of degrees, e.g, phase shift during beamforming), a gain flatness value , an error vector magnitude value (e.g., in units of dBc), an isolation value (e.g., degree of isolation between different directions of polarization), and a noise figure value (or any other metric measurable using an antenna).

[0020] The values allow determining the optimized distance based on parameters related to a reception of the device under test. The optimized distance may be optimized, for example, for testing a reception of the device under test. The method is compatible with a plurality of measurable parameters. Furthermore, since resonance effects may be reflected in a deviation of more than one measurable parameter, the optimized distance may be determined by measurements of one parameter (e.g., a parameter that is strongly affected by resonance effects and / or a parameter that the testing arrangement can measure at a high accuracy) and then use the optimized distance to measure a different parameter.

[0021] According to an embodiment, the second measurement data comprise a first set of near field measurement result values associated with a first distance between the device under test and the antenna of the testing arrangement (e.g. are obtained for the first distance between the device under test and the antenna of the testing arrangement)(wherein, for example, the values of the first set of near field measurement result values are associated with different frequencies, e.g. have been determined for different frequencies), and wherein the second measurement data comprise a second set of near field measurement result values associated with a second distance between the device under test and the antenna of the testing arrangement (e.g. are obtained for the second distance between the device under test and the antenna of the testing arrangement) (wherein, for example, the values of the second set of near field measurement result values are associated with the different frequencies, e.g. have been determined for the different frequencies) (wherein, for example, the values of the first set of near field measurement results may correspond to the values of the second set of near field measurement result values except for the fact that the values of the first set of measurement result values are determined for the first distance and that the values of the second set of near field measurement result values are determined for the second distance), wherein the optimized distance is determined in dependence on deviations between the sets of near field measurement result values and a (corresponding) set of far field measurement result values (which is included in the first measurement data)(wherein the set of far field measurement result values may be considered as reference far field data).

[0022] As a result, the first set of near field measurement result values pertains to the first distance and the second set of near field measurement result values pertains to the second distance. The set of values each define a set that is accessible to statistical processing such that deviations determined for each set allow determining how much the near field measurements have been affected by resonance effects so as to deviate from a non-affected value. Therefore, the deviations determined for each set allows determining distances that are less or not affected by resonance effects, which facilitates determining the optimized distance.

[0023] According to an embodiment, the optimized distance is determined using a plurality of the far field measurement results associated with different frequencies (e.g. of the set of frequencies) and corresponding near field measurement results (which are also associated with the different frequencies, e.g. of the set of frequencies).

[0024] The corresponding frequencies provide a more accurate link for a comparison between the far field measurement results and the near field measurement results. Since the near and far field measurement results may be associated with the same set of frequencies, a comparison between the near and far field measurement results are more accurate.

[0025] According to an embodiment, determining the optimized distance comprises averaging (e.g. without a weighting or with a weighting) a difference between a plurality of the far field measurement results associated with different frequencies (e.g. of the set of frequencies) and corresponding near field measurement results (which are also associated with the different frequencies, e.g. of the set of frequencies).

[0026] Averaging the difference between the plurality of far field measurement results and the corresponding near field results provides a measure for a deviation of the near field measurement results and the near field measurement results. Since the deviation may be caused by resonance effects, the average of the differences may indicate how pronounced the resonance effects at each distance are. A weighted average allows increasing or decreasing the contribution of significant deviations in the average, which may facilitate identifying deviations or reduce the effects of random deviations.

[0027] According to an embodiment, the optimized distance is determined such that a difference between a far field measurement result and a corresponding near field measurement result is smaller than a predetermined maximum deviation for all frequencies of the set of frequencies, or wherein the optimized distance is determined such that a difference between a far field measurement result and a corresponding near field measurement result is smaller than or equal to a predetermined maximum deviation for all frequencies of the set of frequencies.

[0028] A predetermined maximum deviation provides a threshold for determining the severity of differences between the near and far field measurement results. If more than one optimized distance may be determined to have a difference lower than the predetermined maximum deviation, the method may include further selection criteria or the user can select a distance, for example, that may better fit testing parameters (or testing capabilities of the testing arrangement). Furthermore, a plurality of distances having a difference lower than the predetermined maximum deviation may indicate a test system with overall low resonance effects, which may result in more reproducible results. Few or no distances having a difference lower than the predetermined maximum deviation may indicate that there are many resonance effects, which may warn the user of a risk of less reproducible results and may suggest adjusting testing parameters.

[0029] According to an embodiment, the optimized distance is determined such that a near field measurement result or a difference between a far field measurement result and a corresponding near field measurement does not exhibit a resonance effect (e.g. beyond a predetermined maximum deviation) for all frequencies of the set of frequencies (wherein, for example, a presence of a resonance effect can be recognized by a comparison of near field measurement results for a given frequency and for a plurality of distances with an average value of the near field measurement results for the given frequency and for the plurality of distances, wherein a deviation from the average value which is larger than a predetermined threshold value may be recognized as a resonance effect) (e.g. avoiding a distance at which there is a significant resonance effect that significantly degrades a near field measurement result at at least one frequency of the set of frequencies).

[0030] Determining an optimized distance based on resonance effects provides further indicators that can be determined. For example, resonance effects may be defined by a (wavelength dependent) periodicity and distinct formation of minima and maxima dependent on measured values. For example, resonance effects may be identified based on a direction (e.g., sign) or a degree (e.g., magnitude) of deviation. These additional indicators may improve identifying resonance effects and therefore determining distances that are optimized for low or no occurrence of resonance effects.

[0031] According to an embodiment, the method comprises determining, as the optimized distance, a single distance which is used for all frequencies of the set of frequencies (and which brings along acceptable near field measurement results for all frequencies of the set of frequencies).

[0032] A single optimized distance may facilitate automation of testing (e.g., requiring no selection parameters or requiring no selection performed by a user). Using a single distance instead of multiple distances (e.g., for certain frequency bands) improves testing efficiency and comparability. Since the single optimized distance is determined for the set of frequencies, the measurements may have a lower risk of having an asymmetrical behaviour across the set of frequencies.

[0033] According to an embodiment, the method comprises using a production-test test program for obtaining the first measurement data.

[0034] A production-test program can automate determining the optimized distance and may be used for performing further measurements using the optimized distance. As a result, testing can be performed more efficient. Furthermore, testing can be performed more reliable and reproducible by different users while lowering the risk of user mistakes.

[0035] According to an embodiment, the method comprises executing a production-test program, which controls a testing of the device under test (and which preferably returns one or more measurement result values per frequency) for a plurality of test frequencies, for a plurality of distances (e.g. between the device under test and the antenna of the testing arrangement), to thereby obtain the second measurement data. For example, the production-test program may be run for each distance between the device under test and the antenna of the testing arrangement (e.g., AiP DUT antenna array to OTA measurement antenna distance) set by a linear stage (e.g. 20 mm to 40 mm in 1 mm steps). Results (e.g., measurement results) of each test (e.g., each run, e.g., a test for each distance) may be stored, e.g., including (e.g., measurement) results for different measured frequencies (e.g., frequencies of the set of frequencies).

[0036] Such a production-test program extends the advantages described above related to testing efficiency, reliability and reproducibility to the process of performing the measurements for obtaining the second measurement data.

[0037] According to an embodiment, the method comprises using a production-test test program , which is repeated one or more times with modified distance between the device under test and the antenna of the testing arrangement, in order to determine the optimized distance, or wherein the method comprises using a production-test test program, which is supplemented by a functionality to effect a repetition (e.g. of a test flow) and a modification of a distance between the device under test and the antenna of the testing arrangement, in order to determine the optimized distance. For example, after completing measurements for a last distance (e.g., at the end of an entire measurement cycle), results (e.g., measurement results or values based thereon) for each distance value may be, for example, compared to each other in order to determine or identify one or more common distance values for all the frequencies being measured (e.g., the set of frequencies) that do not land on a resonant situation (e.g., exhibit resonance effects or a standing wave).

[0038] The production-test program therefore supports controlling the modification of the distance, which can be performed more efficient. Since the second measurement data forms a basis for determining the optimized distance and potential further testing with said optimized distance, the accuracy of these further testing can be improved.

[0039] According to an embodiment, the method comprises varying a distance between the device under test and the antenna of the testing arrangement between measurements that are used to obtain the near field measurement result (wherein, for example, the distance is varied using an actuator (e.g. an electrical actuator) which may vary a position of the antenna of the testing arrangement; wherein, for example, the method comprises generating control signals for a actuator which varies the position of the antenna of the testing arrangement).

[0040] The use of an actuator allows for a simple design that requires only one antenna that can be driven by the actuator in order to achieve the different distances. Such a actuator can be provided (e.g., in form of a testing device) to already existing testing arrangements, which improves compatibility of the method disclosed herein.

[0041] According to an embodiment, the method comprises step-wisely varying the distance between the device under test and the antenna of the testing arrangement (e.g. using equal and / or fixed steps).

[0042] Varying the distance step-wisely facilitates efficiently and reproducibly locating the antenna at distances required for the second measurement data. A step-wise approach is compatible with repetition of a test program and facilitates determining whether testing has been performed for all desired distances. According to an embodiment, the method comprises determining which subset of the second measurement data, out of a plurality of subsets of the second measurement data (respectively) associated with different distances, comprises a maximum similarity to the first measurement data, and wherein the method comprises determining the optimized distance based thereon.

[0043] A maximum similarity is a criterion that can be defined in various mathematical algorithms and processes (e.g., processes for fitting measured values, using metrics for determining a difference between measured values, determining a variance, applying distance and / or frequency specific weights, determining similarity in a frequency domain), allowing for a criterion that can be customized and that can be efficiently carried out by a program. Furthermore, distances with low or no resonance effects tend to exhibit a larger degree of similarity with the first measurement data and therefore can be used as an indicator for the optimized distance.

[0044] According to an embodiment, the method further comprises determining, for each frequency of the set of frequencies, distances with a standing wave behaviour (e.g., at local maxima of an Si 1 scattering parameter and / or local minima of an S21 scattering parameter), wherein the optimized distance is determined from distances with no or the least standing wave behaviour.

[0045] By determining distances based on standing wave behaviour, further indicators are available that allow testing for the optimized distance. For example, scattering parameters may exhibit local maxima or minima dependent on the presence of a standing wave. Therefore, identifying such local maxima or minima can form a basis for determining standing waves and therefore the optimized distance (with low or no standing waves).

[0046] According to an embodiment, the method may further comprise generating a control signal for controlling movements of a stage (e.g., a linear stage; e.g., with a motor) supporting the antenna of the testing arrangement, wherein the control signal causes the stage to move to at least two of the different distances (e.g., by causing the motor to drive). Alternatively, the movement of the stage may be controlled manually. The control signal allow controlling movement of the stage and therefore the distance between the device under test and the antenna of the testing arrangement. The control signal can be used directly with a linear stage or a motor, which facilitates and expedites performance of the measurement of the second measurement data.

[0047] An embodiment of the invention is directed to a method for testing a plurality of devices under test, wherein the method comprises determining an optimized distance between the device under test and an antenna of the testing arrangement using a method as disclosed herein, wherein the optimized distance is determined using a production-test test program, which is repeated one or more times with a modified distance between the device under test and the antenna of the testing arrangement, in order to determine the optimized distance, or wherein the optimized distance is determined using a productions-test test program, which is supplemented by a functionality to effect a repetition (e.g. of a test flow) and a modification of a distance between the device under test and the antenna of the testing arrangement, in order to determine the optimized distance; and wherein the method comprises testing a plurality of devices under test using the production test program, wherein a distance between the device under test is kept constant at the previously determined optimized distance.

[0048] The method allows automating the steps of determining the optimized distance, modifying the distance, and testing the plurality of devices. Therefore, the production-test program can determine the optimized distance using a first device under test and subsequent testing of further devices under test using the optimized distance. Since the optimized distance is determined in a near field, testing the plurality of devices can also be performed in the near field, which can facilitate high volume testing (e.g., due to a more compact setup) and enables using handler models used in high volume testing of the near field.

[0049] An embodiment of the invention is directed to computer program for performing the method as described herein, when the computer program is executed on a computer (or a computer program product comprising instructions to cause one or more processors to perform a method as described herein). The program may be run on different testing arrangements (e.g., that are new or already exist, or of different users), which increases compatibility with available testing arrangements. Furthermore, the computer program can realize the advantages of the method disclosed herein.

[0050] An embodiment of the invention is directed to a testing arrangement (e.g. a test system or an automated test equipment) for determining an optimized distance between a device under test (e.g., an Antenna in Package)) and an antenna of a testing device, wherein the testing arrangement is configured to obtain first measurement data (e.g. reference far field data) (e.g., the testing arrangement may determine the first measurement data by itself, or may receive the first measurement data from an external source, e.g. if the far field measurements are performed in a different measurement environment), wherein the first measurement data represent a plurality of far field measurement results (e.g. power measurement results and / or gain measurement results and / or gain step measurement results and / or gain compression measurement results and / or phase shift measurement results and / or flatness measurement results and / or error vector magnitude measurement results and / or isolation measurement results and / or spurious emission measurement results and / or adjacent channel power ratio measurement results and / or IP3 measurement results and / or noise figure measurement results) (e.g., based on a measurement at a distance between the device under test and a measurement antenna that is larger than the Fraunhofer distance (dF=2D2 / A wherein D is a largest dimension of a radiator or a diameter of a sphere enclosing the radiator or the antenna, and wherein A is a used wavelength, e.g. a smallest used wavelength or a largest used wavelength or an average used wavelength or a wavelength at an average used frequency); e.g. larger than 10mm) characterizing the device under test for a set of frequencies (e.g. for a plurality of frequencies) (e.g., comprising ten, eleven, or twelve frequencies) (e.g., in a frequency range of 24GHz to 53GHz), or wherein the first measurement data are based on a plurality of far field measurement results characterizing the device under test for a set of frequencies, wherein the testing arrangement is configured to obtain second measurement data (e.g. measurement data for different distances x, for which near field conditions between the device under test and the antenna of the testing arrangement apply) (e.g., generated by the antenna of a testing device) wherein the second measurement data represent a plurality of near field measurement results (e.g. a plurality of sets of near field measurement results associated with different distances) (e.g., measured at distances between the device under test and an antenna of the measurement arrangement which is within the “Fraunhofer distance”) characterizing the device under test for the set of frequencies (wherein the antenna of the measurement arrangement which is used to obtain the near field measurement results may be different from the measurement antenna used to obtain the far field measurement results or may be equal to the measurement antenna used to obtain the far field measurement results), or wherein the second measurement data are based on a plurality of near field measurement results (or a plurality of sets of near field measurement results associated with different distances) (e.g., measured at distances between the device under test and an antenna of the measurement arrangement which is within the “Fraunhofer distance”) characterizing the device under test for the set of frequencies, wherein at least two of the near field measurement results (or at least two sets of near field measurement results) are captured at different distances (in step increments of 1 mm) (in a range of 20mm to 40mm) between the device under test and an antenna of the testing arrangement (wherein the antenna of the testing arrangement may be identical to the measurement antenna used to obtain the far field measurement results or may be different from the antenna used to obtain the far field measurement results), and wherein the testing arrangement is configured to determine the optimized distance between the device under test and the antenna of the testing arrangement based on the first and second measurement data (e.g. based on a comparison between the first and second measurement data)(e.g. taking into consideration measurement data at different frequencies).

[0051] Thus a testing arrangement can be provided that can solve aforementioned problems and provide advantages as described herein.

[0052] According to an embodiment, the testing arrangement further comprises a device socket configured to receive the device under test, wherein the testing arrangement is configured to perform a plurality of tests when the device under test is arranged in the device socket, in order to obtain the near field measurement results for the set of frequencies, wherein at least two of the tests are performed at different distances between the device under test and the antenna of the testing arrangement, in order to obtain near field measurement results for the at least two different distances.

[0053] The socket allows insertion and positioning of the device under test such that the near field measurement results can be obtained accurately and efficiently. Furthermore, the socket facilitates communication of the device under test and the testing arrangement (e.g., a signal source and / or signal receiver thereof), for example in order to control the device under test (e.g., for emission of electromagnetic waves by the device under test) and / or receive signals of the device under test (e.g., related to electromagnetic waves received by the device under test).

[0054] According to an embodiment, the testing arrangement further comprises a stage (e.g., a linear stage; e.g., with a motor) supporting the antenna of the testing arrangement and configured to move (e.g., by operation of the motor) to at least two different distances relative to the device socket. For example, a linear stage may have a motor controlled by the testing arrangement (e.g., an ATE measurement system) that is configured to move the antenna relative to the device under test and / or the device socket (e.g., configured to move an antenna distance in regards to an AiP DUT antenna array). The testing arrangement may comprise an control circuit (e.g., an auxiliary circuit) for controlling the stage (e.g., the motor of the stage). The testing arrangement may be configured to power the motor (e.g., via the control circuit or a separate power circuit). For example, an auxiliary circuit (e.g., of an off the shelf motor control integrated circuit) may be implemented on the carrier structure (e.g., a DUT test fixture or loadboard) for controlling the motor. The testing arrangement may comprise digital channels / resources for controlling or programming a control circuit of the motor and / or may comprise power supply channel / resouces configured to provide power to the motor. In other words, digital channels / resources of, for example, an ATE system may be used to program, for example, a motor controller integrated circuit (IC) and / or a power supply channel / resources, for example, of the ATE system may be used, for example, to provide the needed power to the motor.

[0055] The stage facilitates positioning the antenna for performing measurements at different distances and allows positioning the device under test (and optionally further devices under test) at the determined optimized distance. A motor controllable by the testing arrangement can facilitate automation of distance modification and therefore of measurements of the near and / or far field.

[0056] According to an embodiment, the testing arrangement further comprises a far field testing device configured to perform a test of the device under test at the set of frequencies in a far field condition (e.g. at a sufficiently large distance between the antenna of the testing arrangement and the device under test), in order to obtain the first measurement data. The far field testing device allows determining the first measurement data that serve as a reference data. The testing device may be mounted on an already existing testing arrangements, which improves compatibility of testing arrangements with the method disclosed herein.

[0057] According to an embodiment, the testing arrangement further comprises a data interface (e.g., for user input or data input) configured to receive the first measurement data and / or the second measurement data (e.g., determined at a device different from the testing arrangement).

[0058] The data interface allows performing the measurements of the first measurement data and / or the second measurement data at a different time and / or with a different testing arrangement. Therefore, measurements can be scheduled and performed more flexible (e.g., by a manufacturer of the device under test), which increases efficiency for performing the method and further testing.

[0059] According to an embodiment, the testing arrangement is configured to perform a method as disclosed herein.

[0060] Thus, the testing arrangement can solve problems and provide advantages as described herein in the context of said method.

[0061] Brief Description of the Drawinos

[0062] The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which:

[0063] Fig. 1 shows a perspective view of an example of a testing arrangement with a device under test;

[0064] Fig. 2 shows a perspective view of a close up of the testing arrangement and the device under test shown in Fig. 1 ; Fig. 3 shows a perspective view of an example of a device under test relative to an antenna of a testing arrangement;

[0065] Fig. 4 shows a perspective view of a backside of testing arrangement shown in Figs. 1 and 2;

[0066] Fig. 5 shows a perspective view of an example of a testing arrangement;

[0067] Fig. 6a shows a schematic view of electromagnetic waves emitted by a point source and received by a receiving antenna with a length D;

[0068] Fig. 6b shows a schematic view of example of different electromagnetic fields around an antenna;

[0069] Fig. 6c shows a top view of an example of a device under test;

[0070] Fig. 7 shows a schematic view of an example of different electromagnetic field regions around an antenna under test;

[0071] Fig. 8 shows a flow sheet of a method for determining an optimized distance between a device under test and an antenna of a testing arrangement;

[0072] Fig. 9 shows a flow diagram of an exemplary method for controlling a distance between a device under test and an antenna;

[0073] Fig. 10a shows results of simulations of a transmission of scattering parameters Sn and S21 for different separation distances between the device under test and the antenna;

[0074] Fig. 10b shows results of a phase difference between the simulated S21 transmission phase and a linear phase for different separation distances between the device under test and the antenna;

[0075] Fig. 1 1 a shows an example of first measurement data and second measurement; Fig. 1 1 b shows a selection of values from the first and second measurement data shown in Fig. 1 1 a;

[0076] Fig. 12a shows sets associated with the first and second measurement data of Fig. 1 1 a;

[0077] Fig. 12b shows an example of deviations for the sets of Fig. 12a;

[0078] Fig. 13 shows a flow diagram of an exemplary method for testing a plurality of devices under test;

[0079] Fig. 14a shows a schematic view of an example of a device under test; and

[0080] Fig. 14b shows a schematic view of another example of a device under test.

[0081] Detailed Description of the Embodiments

[0082] Equal or equivalent elements or elements with equal or equivalent functionality are denoted in the following description by equal or equivalent reference numerals even if occurring in different figures.

[0083] In the following description, a plurality of details is set forth to provide a more throughout explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form rather than in detail in order to avoid obscuring embodiments of the present invention. In addition, features of the different embodiments described herein after may optionally be combined with each other, unless specifically noted otherwise.

[0084] In the following, examples of a testing arrangement for determining an optimized distance between a device under test and an antenna of a testing arrangement will be described. Subsequently, a method for determining the optimized distance (e.g., using such a testing arrangement) will be described further below. Fig. 1 shows a perspective view of an example of a testing arrangement 120 with a device under test 110.

[0085] The testing arrangement 120 may comprise a carrier structure 126 (e.g., comprising a printed circuit board, e.g., a PCB test fixture). The testing arrangement 120 may comprise a signal source and / or signal receiver 129 configured to transmit signals to an antenna 122 (e.g., OTA measurement antenna) of the testing arrangement 120 and / or receive signals from the antenna 122 of the testing arrangement 120. The testing arrangement 120 may be an automatic testing equipment (ATE).

[0086] The testing arrangement 120 may comprise a device socket 128 for insertion of (e.g., configured to receive) the device under test 110. The testing arrangement 120 may be configured to perform a plurality of tests when the device under test 1 10 is arranged in the device socket 128, in order to obtain far field measurement results and / or near field measurement results for a set of frequencies. At least two of the tests of the near field may be performed at different distances between the device under test 1 10 and the antenna 122 of the testing arrangement, in order to obtain near field measurement results for the at least two different distances.

[0087] Fig. 2 shows a perspective view of a close up of the testing arrangement 120 and the device under test 110 shown in Fig. 1 .

[0088] The testing arrangement 120 comprises an antenna 122 (e.g., a measurement patch), which may be configured to detect an electromagnetic field emitted by the device under test 110 and / or emit an electromagnetic field to be received by the device under test 1 10.

[0089] The antenna 122 may be connected (or connectable) via coaxial cables 129a, b to connectors of the signal source and / or signal receiver 129 (e.g., directly or indirectly via the carrier structure 126). The device socket 128 may be coupled with the signal source and / or signal receiver 129 (e.g., directly or indirectly via the carrier structure 126). As a result, when the device under test 1 10 is inserted in the device socket 128, the signal source and / or signal receiver 129 may be configured to receive signals from the device under test 110 (e.g., wherein device under test 110 generates the signal as a response to receiving an electromagnetic field from the antenna 122) and / or transmit signals to the device under test 1 10 (e.g., which may cause the device under test 1 10 to generate a signal to be received by the antenna 122). Furthermore, the signal source and / or signal receiver 129 may be configured to receive signals from the antenna 122 (e.g., wherein antenna 122 generates the signal as a response to receiving an electromagnetic field from the device under test) and / or transmit signals to the antenna 122 (e.g., which may cause the antenna 1 12 to generate a signal to be received by device under test 1 10).

[0090] The antenna 122 shown in Fig. 2 is implemented (e.g., manufactured, e.g., provided) on (or as) a printed circuit board (PCB) coupled to the coaxial cables 129a, b. For example, the PCB may be the antenna 122 or may comprise the antenna 122. For example, the antenna 122 may be formed by at least one of circuitry printed on the PCB and circuitry mounted on the PCB (e.g., in form of one or more electrical components such as a chip mounted on the PCB). The antenna 122 may comprise the PCB and may optionally comprise further components (e.g., a holding frame for handling). However, the antenna 122 may be structured differently. For example, the antenna 122 may comprise an antenna housing (e.g., formed from metal) having a waveguide (e.g., with a double-ridged structure or a quad-ridged structure) formed therein that is coupled to an opening (e.g., radiating aperture, e.g., comprising a circular polarizing antenna structure) of the antenna housing.

[0091] The testing arrangement 120 may comprise a testing device 140 that comprises the antenna 122 and a support structure 142 supporting the antenna 142. The testing device 140 (or the testing arrangement 120) may comprise a (e.g., linear) stage 144 configured to be movable relative to the device socket 128 (e.g., in a direction along a main lobe of the device under test 110 in the device socket 128, e.g., in a direction perpendicular to a radiating surface of the device under test 1 10 in the device socket 128, e.g., perpendicular to the carrier structure 126). The testing device 140 may comprise a motor 146 configured to move the stage 144 (e.g., using a screw-and-nut system assembled on a shaft rotatable by the motor 146). Alternatively, the testing device 140 may be configured to move the device socket 128 relative to the carrier structure 126. The testing device 140 comprises electrical connections 148 (e.g., a motor control cable) for coupling the motor 146 to the signal source and / or signal receiver 129 or a computer (e.g., an ATE system, e.g., connected to the signal source and / or signal receiver 229).

[0092] The method may comprise generating (e.g., by the signal source and / or signal receiver 229 or the computer) a control signal for controlling movements of the stage 144 supporting the antenna 142 of the testing arrangement 120, wherein the control signal causes the stage 144 to move to at least two of the different distances (e.g., by causing the motor 146 to drive). Alternatively or additionally, the testing device 140 may comprise a plurality of antennas arranged at different distances relative to the device socket 128. The plurality of antennas may allow measurements at different distances with less or no movement of the state 144.

[0093] Fig. 3 shows a perspective view of an example of a device under test 310 relative to an antenna 322 of a testing arrangement. The device under test 310 may be any device under test disclosed herein (e.g., device under test 110 or 510). The antenna 322 may be any antenna of a testing arrangement disclosed herein (e.g., testing arrangement 120 or 520).

[0094] The device under test 310 (e.g., device under test patch) may be (or comprise) an Antennain-Package (AiP). The device under test 310 may comprise at least one of an antenna, an antenna array (e.g., capable of beamforming), and a circular polarization antenna structures. The device under test 310 may be configured for reception / or emission of signals in 5G (NR) frequency bands. For example, the device under test 310 may be configured to emit and / or receive signals in the frequency range 2 (FR2), e.g., between 24 GHz and 53 GHz. The device under test 310 may be an antenna device used in applications for in a mobile phone, a car, television, or a computer. The device under test 310 may have a first port 312 coupled or coupleable with a signal source and / or signal receiver (e.g., signal source and / or signal receiver 129).

[0095] The antenna 122 (e.g., a measurement patch) (which is part of a testing arrangement such as, for example an automatic test equipment, ATE) may be configured to detect an electromagnetic field emitted by the device under test 1 10 and / or emit an electromagnetic field to be received by the device under test 1 10. The antenna 122 may have a second port 124 for a signal source and / or signal receiver (e.g., signal source and / or signal receiver 129).

[0096] Fig. 14a shows a schematic view of an example of a device under test 1410a.

[0097] The device under test 1410a comprises, for example, a transceiver 1416 (e.g., a 5G transceiver) and a front end 1417a (e.g., a 5G front end). For transmission, the transceiver 1416 may be configured to generate a radio frequency (RF) signal based on a signal of a base band 1415a and to provide the RF signal to the front end 1417a. The front end 1417a may comprise or be coupled to one or more antennas, with which a wireless signal based on the RF signal can be emitted. For reception, a wireless signal received by the one or more antennas may be converted at the front end 1417a to a RF signal that is provided to the transceiver 1416.

[0098] Fig. 14b shows a schematic view of another example of a device under test 1410b.

[0099] The device under test 1410b comprises, for example, an intermediate frequency (IF) transceiver 1418a, a radio frequency (RF) transceiver (TRX) 1418b, and a front end 1417b (e.g., a 5g front end). For transmission, the IF transceiver 1418a may generate an IF signal based on a signal of a base band 1415b and forward the RF signal to the RF transceiver 1418b, which may generate an RF signal based on the IF signal. The front end 1417b may comprise or be coupled to one or more antennas, with which a wireless signal based on the RF signal can be emitted. For reception, the RF transceiver 1418b may be configured to generate an RF signal based on a wireless signal received by the one or more antennas and forward the RF signal to the IF receiver 1418a. The IF receiver 1418a may be configured to generate a signal of a base band 1415b based on the IF signal.

[0100] The devices under test 1410a, b shown in Figs. 14a, b provide examples of components that contribute to signal processing, each of which may contribute and effect transmission and / or reception of the device under test 1410a, b. Testing of the device under test 1410a, b may allow determining deviations of device functionality and / or defects of the device under test. Such testing may be improved by the method and testing arrangement disclosed herein, e.g., in terms of accuracy (e.g., by determining an optimized distance with fewer or no resonance effects) and testing efficiency (e.g., by enabling the use of near field testing arrangements with high volume production testing).

[0101] Fig. 4 shows a perspective view of a backside of testing arrangement 120 shown in Figs. 1 and 2.

[0102] The testing device 140 may comprise a sensor 150 configured to detect a pre-defined position of the stage 144. For example, the sensor 150 may comprise a (e.g., reset) switch that detects (e.g., and signals to the signal source and / or signal receiver 129 or a computer) a physical contact between a reference structure 152 of the testing device 140 and the switch. The pre-defined position of the stage 144 can be used as a reference point (e.g., starting or end point) for movement of the stage 144. In other words, the (reset) switch provides, for example, a reference point for the (linear) stage 144. For example, a dimensional measurement is done, for example, at that reset point of the distance between the device under test 1 10 (e.g., AiP DUT antenna array) and the device socket 128 (e.g., ATE OTA socket) and the antenna 122 (e.g., measurement antenna).

[0103] Fig. 5 shows a perspective view of an example of a testing arrangement 520, which can take the place of any testing arrangement disclosed herein (such as testing arrangement 120). For example, the testing arrangement 520 may be a far-field testing arrangement.

[0104] The testing arrangement 520 comprises an antenna 522 configured to detect and / or emit electromagnetic fields. The antenna 522 shown in Fig. 5 may have a frequency range of 18.0 to 54.0 GHz, a gain of typ. 15 d Bi , Dual Polarization, a 3dB Beamwidth of 54 to 21 deg, a Cross Polarization Isolation of typ. 30 dB (minimum 20 dB), a Port to Port Isolation of typ. 35dB (minimum 25 dB), a voltage standing wave ratio (VSWR) of typ. 1 .5:1 and maximum 2.0:1 , a 2.4mm-Female connector or 1 .85mm-Female connector, and a power handling of maximum 10 W continuous wave (CW) (2.4mm-Female connector) or of maximum 5 W CW (1 .85mm-Female). The antenna may be formed of or comprise Aluminum. For example, a size of the antenna (dimensions ) may be 33.4mm x 33.4mm x 61 ,5mm. A net weight of the antenna may, for example, be around 0.07kg.

[0105] The testing arrangement 520 may comprise a carrier structure 526 (such as the carrier structure 126). The testing arrangement 520 may comprise a signal source and / or signal receiver 529 (such as signal source and / or signal receiver 129) configured to transmit signals to the antenna 522 (such as antenna 122) and / or receive signals from the antenna 522. The antenna 522 may be connected (or connectable) via coaxial cables 529a, b to connectors of the signal source and / or signal receiver 529 (e.g., directly or indirectly via the carrier structure 526).

[0106] The testing arrangement 520 may comprise a device socket 528 (such as device socket 128) for insertion of (e.g., configured to receive) the device under test 510 (such as device under test 110). The testing arrangement 520 may be configured to perform a plurality of tests when the device under test 510 is arranged in the device socket 528, in order to obtain the far field measurement results and / or near field measurement results for the set of frequencies.

[0107] The device socket 528 may be coupled with the signal source and / or signal receiver 529. As a result, when the device under test 510 is inserted in the device socket 528, the signal source and / or signal receiver 529 may be configured to receive signals from the device under test 510 and / or transmit signal to the device under test 510.

[0108] The testing arrangement 520 may comprise a testing device 540 that comprises the antenna 522 and a support structure 542 supporting the antenna 542. The support structure 542 may be (releasably) attached to at least one of the carrier structure 526, the device socket 528, and the signal source and / or signal receiver 529. The support structure 542 may be height-adjustable or rigid. The testing device 540 may comprise a set of (e.g., interchangeable) support structures 542, wherein each of the set of support structures 542 is configured to arrange the antenna 522 at a different distance (e.g., height) relative to the device socket 528.

[0109] The antenna 522 may be arranged (e.g., by the support structure 542) such as to allow measuring a far field of the device under test 510. In the example shown in Fig. 5, the antenna is arranged at a distance of 25 cm from the device under test 510. However, longer distances or shorter distances (e.g., 10 mm) are also possible. For example, the distance between the antenna 522 and the device under test 510 may be larger than the Fraunhofer distance.

[0110] The Fraunhofer distance is defined by the equation dp=2D2 / A wherein D is a largest dimension of a radiator or a diameter of a sphere enclosing a radiator or an antenna, and wherein A is a used wavelength, e.g. a smallest used wavelength or a largest used wavelength or an average used wavelength or a wavelength at an average used frequency.

[0111] Fig. 6a shows a schematic view of electromagnetic waves emitted by a point source 630 and received by a receiving antenna 632 with a length D. It is noted that the same principle applies if the receiving antenna 632 emits electromagnetic waves received by the point source 630. In the context of Figs. 6a-c, the term “antenna” is used for any object emitting (or receiving) an electromagnetic field, not only an antenna of a testing arrangement.

[0112] Due to its limited size, the receiving antenna 632 cannot receive an electromagnetic wave emitted by the source 630 in its entirety (i.e. an entire spherical wavefront), but, in essence, a portion thereof that is covered by its largest dimension, i.e. the length D. This aspect is visualized in Fig. 6a in form of waves that are clipped to a vertical length D. As can be seen in Fig. 6a, a wave front of first wave 634a that is close to the points source 630 has a large curvature (i.e. a small radius, e.g., less planar), whereas wave front of a second wave 634b that is further away from the point source 630 than the first wave 634a has a smaller curvature (i.e. a larger radius, e.g., more planar). The curvature causes a phase difference At|> of an electromagnetic wave received along the length D of the receiving antenna 632. With a larger distance, the curvature of the wave front and the phase difference A<|) decreases (e.g., has a more planar shape). At the Fraunhofer distance dF=2D2 / A, the phase difference varies by no more than TT / 8 radians. In other words, the physical significance of this distance is that a radiating point source with a distance of 2D2 / A or more from a receiving antenna of length D would produce a spherical wave front such that, over the entire length D, the phase would vary by no more than TT / 8 radians.

[0113] Fig. 6b shows a schematic view of example of different electromagnetic fields around an antenna.

[0114] A region located at a distance below the Fraunhofer distance R0=dF=2D2 / A may be defined as the near field, which can be separated into a Fresnel region (or radiating near field) with a radius Ro smaller than the Fraunhofer distance Ro=dF=2D2 / A and larger than R=0.62*(D3 / A)°5and a (reactive) near field for a distance smaller than R=0.62*(D3 / A)05.

[0115] Fig. 6c shows a top view of an example of a device under test 610. The device under test 610 shown in Fig. 6c may be implemented as any device under test disclosed herein and used in any testing arrangement disclosed herein.

[0116] The device under test 610 comprises an antenna array 613 comprising four single antennas 614a, b, c, d. The largest dimension Dsaof a single antenna 614a-d is approximately 4.4mm and the largest dimension Daaof the antenna array 613 is approximately 23.1 mm. A wavelength Ao (measured in mm) in air may be determined by the following formula with a relative permittivity sr=1 .00059 (of air at 1 atm). For an exemplary frequency of 24 GHz, a wavelength may be determined as

[0117] AQ(24 GHZ) = 12.45 mm

[0118] Using the largest dimensions of the antenna array 613 (e.g., 23.1 mm) and the single antenna 614a (e.g., 4.1 mm) in Fig. 6c and a wavelength of 12.45 mm, the Fraunhofer distances (and therefore a lower threshold for the far field) can be calculated as for the antenna array 613 and for each one of the single antennas 614a, b, c, d.

[0119] It is noted described above are examples of a distance defining regions of a near field and a far field, wherein such a distance is exemplarily described with Fraunhofer distances at 24 GHz. Other definition for the distance separating the near and far field, as well as other parameters defining the distance (e.g. antenna dimensions and frequencies) may be used.

[0120] Fig. 7 shows a schematic view of example of different electromagnetic field regions around an antenna under test (AUT) 730.

[0121] The parameter D may be defined as a diameter of an enclosing sphere around the antenna under test 630.

[0122] As can be seen in Fig. 7, a reactive near field may be defined up to a distance of A / 2TT. A radiating near field (or Fresnel region) may be defined up to a distance of 2D2 / A (or Fraunhofer distance). A region with a distance larger than the Fraunhofer distance 2D2 / A may be defined as the far field (or Fraunhofer distance). In the far field, angular variation is less dependent on a distance and waves are locally more plane. In the reactive near field, nonradiating fields dominate.

[0123] Compared to the near field, the far field is usually a better region for over the air (OTA) testing. However, mechanical requirements may make multi-site integration in a standard test cell difficult (low multi-site count). For example, commercial handlers may not have that much space available, for example, for integrating such a large mechanical setup. E.g., commercial handlers might have only, for example, 5 cm distance available between a device under test and a measurement antenna. For implementing, for example, a 30 cm distance (e.g., for far-field testing) a completely new or significantly modified handler design may be required. Also, in a multi-site setup, for example, isolation between adjacent far- field setups may be challenging. E.g., a small anechoic chamber box may have to be created, for example, for each site limiting the possible number of sites for a test cell (e.g. to two sites only instead of more sites such as the traditional eight sites). In other words, the near field may not be a good region, e.g., for OTA testing (compared to the far field). However, its mechanical dimensions may facilitate, e.g., multi-site integration in a standard test cell (high multi-site count).

[0124] Fig. 8 shows a flow sheet 800 of a method for determining an optimized distance between a device under test and an antenna of a testing arrangement.

[0125] The method will be described in the following primarily referencing the testing arrangement 120 shown in Fig. 1 and 2. However, any testing arrangement disclosed herein (such as testing arrangements 120 and 520) may be used (alone or in combination with other testing arrangmenets) to performed any method disclosed herein.

[0126] The method comprises, in step 802, obtaining first measurement data, wherein the first measurement data represent a plurality of far field measurement results characterizing the device under test 1 10 for a set of frequencies, or wherein the first measurement data are based on a plurality of far field measurement results characterizing the device under test 110 for a set of frequencies.

[0127] The method comprises, in a step 804, obtaining second measurement data, wherein the second measurement data represent a plurality of near field measurement results characterizing the device under test for the set of frequencies wherein the second measurement data are based on a plurality of near field measurement results characterizing the device under test for the set of frequencies, wherein at least two of the near field measurement results are captured at different distances between the device under test and an antenna of the testing arrangement. The method comprises, in a step 806, determining the optimized distance between the device under test and the antenna of the testing arrangement based on the first and second measurement data.

[0128] The method may comprise determining, as the optimized distance, a single distance which is used for all frequencies of the set of frequencies. Alternatively, the method may comprise determining more than one optimized distance (e.g., used for all frequencies of the set of frequencies, or used for a sub-set of the set of frequencies).

[0129] The first measurement data may be obtained using measurements performed by the testing arrangement 120. For example, the stage 144 may be arranged at a position, wherein the antenna 122 is arranged at such a distance (e.g., the Fraunhofer distance, a multiple of the Fraunhofer distance, or a pre-defined distance such as 10cm, 20cm or 25cm) as to be located in a far field of the device under test 110. The stage 144 may be driven to the distance by operation of the motor 146 or manually. The stage 144 may be arranged at the distance by selecting a carrier structure 126 with the (target) distance out of the set of support structures 542 and mounting the selected carrier structure 126 on the carrier structure 126. The testing device 140 may comprise a plurality of antennas arranged at different distances relative to the device socket 128, wherein the measurements for the first measurement data are performed by controlling (e.g., causing emission of electromagnetic waves from and / or reading out received electromagnetic waves from) an antenna of the plurality of antennas with a (target) distance to the device under test 110.

[0130] The first measurement data may be obtained by measurements performed by a further testing arrangement that is different from the testing arrangement (such as testing arrangement 120) performing measurements of a near field of the device under test 1 10. For example, measurements for generating the first measurement data may be performed at a manufacturing site of the device under test 110, wherein the device under test and the first measurement data are subsequently provided to the testing arrangement 120 (or a device controlling the testing arrangement 120) for performing the method disclosed herein. T o this end, the testing arrangement 120 may comprise a data interface configured to receive the first measurement data and / or second measurement data. For example, the first and / or second measurement data may be received via an internet connection or a storage device (e.g., a compact disk or a flash drive), wherein a program configured to performed any method disclosed herein may be compatible with and / or allows importing the first and / or second measurement data. The testing arrangement 520 shown in Fig. 5 may be used to perform measurements for the first and second measurement data. However, the testing arrangement 520 may be used to perform the measurements only for the first measurement data (or only for the second measurement data).

[0131] The testing arrangement 520 may form a far field testing device. Alternatively, a part of the testing arrangement 520 may form a far field testing device. For example, the testing device 540 may form the far field testing device, wherein the testing device 540 comprises an antenna 522 and a support structure 542 suitable (e.g., dimensioned) for the far field measurements. In such a case, the testing device 540 may be arranged on a carrier structure (e.g., carrier structure 126 or 526) of the testing arrangement (e.g., instead of or in addition to a support structure for supporting an antenna for near field measurements).

[0132] The method may comprise using a production-test program for obtaining the first measurement data. The production-test program may define the set of frequencies or include an algorithm for determining the set of frequencies based on a user input. The production-test program may define a distance for the far field measurement. The production-test program may include instructions for controlling an actuator (e.g., motor 146) of the testing arrangement 120 for moving the antenna 122 at the distance for the far field measurement. The testing arrangement (e.g., testing arrangement 120 or 520) may comprise a computer for running the production-test program or be communicatively coupled to a computer for running the production-test program. Such a computer program may be provided to a manufacturer of the device-under-test to facilitate reproducible and uniform measurements.

[0133] The set of frequencies may define two or more frequencies, such as three, four, five, six, twelve or more frequencies. At least some frequencies of the set of frequencies may be separated by equal frequency or wavelength intervals. The set of frequencies may cover one or more frequency bands of 5G technology. For example, the set of frequencies may define twelve frequencies (e.g., with an equal frequency interval of approximately 2.6 GHz) covering a range from 24 GHz to 53 GHz. In such a case, the set of frequencies may define twelve frequencies f1 to f 12 as f1 = 24 GHz, f2 « 26.6 GHz, f3 « 29.3 GHz, f4 « 31 .9 GHz, f5 « 34.5 GHz, f6 « 37.2 GHz, f7 « 39.8 GHz, f8 « 42.5 GHz, f9 « 45.1 GHz, f10 = 47.7 GHz, f11 « 50.4 GHz, and f 12 = 53 GHz. Alternatively, the set of frequencies may be defined in other step sizes such as in 1 GHz steps. Further alternatively, the set of frequencies may be defined in unequal (e.g., arbitrary, increasing, or decreasing) step sizes. The plurality of far field measurement results may include at least one of power measurement results (e.g., of the transmission and / or reception of the device under test), gain measurement results(e.g., of the transmission and / or reception of the device under test), gain step measurement results (e.g., of the transmission and / or reception of the device under test), gain compression measurement results, phase shift measurement results (e.g., of the transmission and / or reception of beamforming of the device under test), flatness measurement results (e.g., of the transmission and / or reception of the device under test), error vector magnitude measurement results (e.g., of the transmission and / or reception of the device under test), isolation measurement results (e.g., of the transmission and / or reception of the device under test), spurious emission measurement results, adjacent channel power ratio measurement results, IP3 measurement results, noise figure measurement results.

[0134] The the first measurement data represent a plurality of far field measurement results characterizing the device under test for a set of frequencies (e.g., in form of directly measured calibrated units or arbitrary units) or are based on a plurality of far field measurement results characterizing the device under test for a set of frequencies (e.g., having been further processed, e.g., having been subjected to at least one of filtering, rescaling, noise removal, transforming, convoluting, clipping, and compressing).

[0135] The first measurement data, or at least one or more values of the first measurement data, may be obtained based on a wireless transmission of a signal by the device under test 110 or are obtained when the device under test 110 is wirelessly transmitting a signal (e.g., to the testing arrangement 120 or another testing arrangement for the first measurement; e.g. to the antenna 122 of the testing arrangement 120).

[0136] The second measurement data may be obtained for different distances x, for which near field conditions between the device under test and the antenna of the testing arrangement apply (e.g., a threshold between the far field and the near field such as the Fraunhofer distance 2D2 / A).

[0137] The second measurement data may comprise a first set of near field measurement result values associated with a first distance between the device under test 1 10 and the antenna 122 of the testing arrangement 122 (e.g. are obtained for the first distance between the device under test 110 and the antenna 122 of the testing arrangement 120)(wherein, for example, the values of the first set of near field measurement result values are associated with different frequencies, e.g. have been determined for different frequencies). The second measurement data may comprise a second set of near field measurement result values associated with a second distance between the device under test 1 10 and the antenna 122 of the testing arrangement 120 (e.g. are obtained for the second distance between the device under test 1 10 and the antenna 122 of the testing arrangement 120) (wherein, for example, the values of the second set of near field measurement result values are associated with the different frequencies, e.g. have been determined for the different frequencies).

[0138] The values of the first set of near field measurement results may correspond to the values of the second set of near field measurement result (e.g., measured for at least essentially the same frequencies or subset of frequencies) values except for the fact that the values of the first set of measurement result values are determined for the first distance and that the values of the second set of near field measurement result values are determined for the second distance.

[0139] The second measurement data may comprise one or more values, wherein the one or more values of the second measurement data comprise at least one of a power value (e.g. in milliwatts or dBm), a gain value (e.g., in units of decibel), a gain step value (e.g., in units of decibel), a gain compression value (e.g., 1 dB compression point (P1db)), a phase shift value (e.g., in units of degrees, e.g., phase shift during beamforming), a gain flatness value, an error vector magnitude value (e.g., in units of dBc), an isolation value (e.g., degree of isolation between different directions of polarization), a spurs value (e.g. indicating spurious emissions), and an adjacent channel power ratio value.

[0140] The second measurement data, or at least one or more values of the second measurement data, may be obtained based on a wireless transmission of a signal by the device under test 1 10 or are obtained when the device under test 1 10 is wirelessly transmitting a signal (e.g., to the testing arrangement 120 for the second measurement; e.g. to the antenna 122 of the testing arrangement 120).

[0141] The method may comprise executing a production-test program, which controls a testing of the device under test 110 (and which preferably returns one or more measurement result values per frequency) for a plurality of test frequencies, for a plurality of distances (e.g. between the device under test 1 10 and the antenna 1 12 of the testing arrangement 120), to thereby obtain the second measurement data. The production-test program may assign the pre-determined values for the plurality of test frequencies and / or for the plurality of distances to different types of device under tests 110 (e.g., from different manufactures or different production lines of a manufacturer). The production-test program may be configured to identify a device under test 1 10 based on a user input, a time schedule, or an optical sensor and set the pre-determined values for the plurality of test frequencies and / or for the plurality of distances based on the identified device under test 110. At least one of the plurality of test frequencies and the plurality of distances may be set by a user.

[0142] The method may comprise using a production-test test program, which is repeated one or more times with a modified distance between the device under test 110 and the antenna 122 of the testing arrangement 120. The method may comprise using a production-test test program, which is supplemented by a functionality to effect a repetition (e.g. of a test flow) and a modification of a distance between the device under test 110 and the antenna 122 of the testing arrangement 120. For example, the production-test test program may initiate a function for modifying the distance and subsequently initiate a function for testing at the set of frequencies (wherein the set of frequencies may be identical or change, e.g., based on the distance).

[0143] The method may comprise varying a distance between the device under test 1 10 and the antenna 122 of the testing arrangement 120 between measurements that are used to obtain the near field measurement result (wherein, for example, the distance is varied using an actuator (e.g. an electrical actuator, e.g., the motor 146) which may vary a position of the antenna 122 of the testing arrangement 120). The method may comprise generating control signals for an actuator (e.g., motor 146) which varies the position of the antenna 122 of the testing arrangement 120). The method may comprise step-wisely varying the distance between the device under test and the antenna of the testing arrangement (e.g. using equal and / or fixed steps or varying step sizes).

[0144] The method may comprise generating a control signal for controlling movements of the stage 144 (e.g., a linear stage; e.g., with a motor) supporting the antenna 122 of the testing arrangement 120, wherein the control signal causes the stage to move to at least two of the different distances (e.g., by causing the motor 146 to drive).

[0145] The method may comprise generating a control signal for moving the stage 144 to an initial pre-defined position (e.g., using a signal of the sensor 150; using a signal of a reset switch). The method may further comprise generating a control signal for moving the stage 144 from the initial pre-defined position by a distance increment.

[0146] Fig. 9 shows a flow diagram 960 of an exemplary method for controlling a distance between a device under test 110 and an antenna 120 of the testing arrangement 120. However any of the steps of the method may be used with any other testing arrangement and / or device under test disclosed herein.

[0147] The method may comprise, in step 961 , initiating a reset of a position of a stage (e.g., stage 144) supporting the antenna 122. The method may comprise resetting a stage to a predefined start position (e.g., resetting a linear stage to a defined start position). The reset may be initiated by at least one of a user input, a production-test test program, a switch of the testing arrangement, and one or more sensors detecting that one or more criteria are met (e.g., the device under test 1 10 being inserted into the device socket 128 and / or the testing device 140 being coupled to the carrier structure 126).

[0148] The method may comprise, in step 962, moving the stage 144 to a pre-defined position xmin (e.g., moving a linear stage to xmin). The method may comprise reducing a distance between the device under test 110 and the antenna 122 (or stage 144) until a criterion is fulfilled. The criterion may comprise one of the stage 144 coming to a stop (e.g., due to being moved to an end stop) and the sensor 150 detecting a pre-defined position (e.g., a contact between the reference structure 152 and the switch of the sensor 150). The pre-defined position may be the position in which the criterion is fulfilled or may be a position offset relative to the position in which the criterion is fulfilled. For example, the stage 144 may be moved (e.g., downwards) to an end stop and then be moved by a predetermined increment (e.g., upwards) to the pre-defined position xmin. In other example, the stage 144 may be moved (e.g., downwards) until the sensor 150 detects a contact between the reference structure 152, which defines the pre-defined position xmin. In another example, the stage 144 may be moved (e.g., downwards) until the sensor 150 detects a contact between the reference structure 152 and the switch of the sensor 150 whereupon the stage 144 is subsequently moved (e.g., upwards) a predetermined increment or until the sensor 150 senses no more contact between the reference structure 152 and the switch of the sensor 150.

[0149] The method may comprise, in step 963, setting a parameter px(which may be the distance x or a parameter representative of the distance x or representative of the position of the stage 144) to a value px,min (which may be or be representative of the pre-defined position Xmin). The parameter pxmay be measured in a distance (e.g., in millimeter), in a position of a movable element (e.g., shaft rotatable by the motor 135) of the motor 135 or any other parameter indicative of the position of the stage 144 (or position of the antenna 122).

[0150] The method may comprise, in step 964, running a test program for the set of frequencies to be tested and log (e.g., at least one of scale, process, and store) results. The test program may comprise any method disclosed herein for testing the near field of the device under test 110.

[0151] The method may comprise, in step 965, setting the parameter pxto a new value that is a sum of the previous value pxand a value px,steP, which may be or be representative of a step (interval) or distance difference xstep. The value px,steP(and / or xstep) may be a constant (e.g., predetermined) value or vary with each step. For example, the value px,stePmay dependent on at least one of the distance x, the parameter px, and a gradient of x or px,step). For example, the value px,stePmay define or correspond to a step interval between 0.1 to 2.0mm (e.g., 1 mm).

[0152] The method may comprise, in step 966, comparing whether the (new) parameter pxexceeds a threshold px,max, which may be or represent a threshold distance xmax. The threshold distance Xmax may be at least one of a largest distance that the stage 144 can be moved to, a predetermined threshold, a distance that defines a transition between near field and far field (e.g., the Fraunhofer distance), and a threshold associated with the device under test 1 10. The predetermined threshold (and therefore, for example, the threshold distance xmax) may be defined based on one or more geometrical properties of a predetermined testing arrangement such as a testing arrangement to be used for subsequent measurements (e.g., using the optimized distance). For example, the predetermined threshold may be or may be based on a maximum distance (e.g., between the device under test 1 10 and an antenna of the testing arrangement) allowed by the testing arrangement. The predetermined testing arrangement (e.g., for the subsequent measurements) may be a commercial handler or a high-volume handler. The handler may, for example, comprise a coupling mechanism (e.g., comprising clamps) configured to couple with a socket (e.g., any device socket disclosed herein) or a carrier structure (e.g. any carrier structure disclosed herein) so as to arrange the antenna of the handler at a predefined distance relative to a device under test (e.g., any device under test disclosed herein). For example, the predefined distance between the antenna of the handler and the device under test may be in a range between 4cm and 6cm such as 5cm. The predetermined threshold (and therefore, for example, the threshold distance Xmax) may be the predefined distance of the handler. However, the predetermined distance may be defined based on the predefined distance, for example, in order to take into account one or more factors such as a thickness of the antenna of handler and / or a thickness of the device under test. For example, the predefined distance between the antenna of the handler and the socket may be, for example, 5cm, a thickness of the antenna of the handler may be, for example, 0.1cm, and a thickness of the device under test may be, for example, 0.2cm. In such a case, the predetermined threshold (and therefore, for example, the threshold distance xmax) may be 5cm-0.1cm-0.2cm=4.7cm. In other words, the predetermined threshold (and therefore, for example, the threshold distance xmax) may be a maximum distance allowed by a commercial handler, for example, for a standard (e.g., no modification) integration of an over-the-air (OTA) test setup. For example, that distance (for example, the threshold distance xmax) might be 5 cm or 4 cm (or a range between 4cm and 5cm) depending on multiple factors, for example, measurement antenna thickness, device under test package thickness. Step 966 may, in essence, serve as a check for whether the stage 144 has reached a final distance of a distance range to be tested.

[0153] If the comparing step 966 concludes that the parameter pxdoes not exceed the threshold Px,max, the method may further comprise, in step 967, moving the stage 144 (e.g., up) by the step Xstep (e.g., within a range of 0.1 mm to 2.0mm, e.g., 1 mm) that corresponds to the value Px.step. Subsequently, the method may repeat the steps 964, 965, 966 as discussed above.

[0154] If the comparing step 966 concludes that the parameter pxdoes exceed the threshold px,max, the method may comprise, in step 967, completing the second measurement data (e.g., near field measurement data). The second measurement data may be generated after measuring the near field at the last distance (e.g., based on temporary data) or be generated continuously during measurements at each distance.

[0155] An example of values of a near field measurement determined for different distances will be described with reference to Figs. 10a, b. Subsequently, an example for determining an optimized distance as shown in Fig. 9 will be described.

[0156] Fig. 10a shows results of a simulation of scattering parameters Sn (reflection) and S21 (transmission) for different separation distances between the device under test 1 10 which also corresponds to port 1 on the scattering parameters and the antenna 122 which also corresponds to port 2 on the scattering parameters. The simulations were performed for a simple case, in which the device under test is implemented, for example, as a patch antenna (e.g., such as the device under test 310 in Fig. 3) and the antenna 12 is implemented, for example, as a measurement patch as (e.g., such as antenna 322 in Fig. 3). The simulations are performed with an exemplary wavelength of 12.49mm, which corresponds to 24GHz (i.e. a lower end of the FR2 frequency range).

[0157] The results of the simulation depicted in Fig. 10a show, for example, a standing wave behavior for a simple case of a patch antenna. For example, in an ideal case, for specific distances between the device under test (e.g., AiP DUT antenna array) and the antenna 12 (e.g., OTA measurement antenna), a resonant behavior may occur. The resonant behavior results in variations for different distances. Such a resonant behavior may have, for example, a periodicity of half the wavelength (e.g., approximately 6.2mm) of the transmitted wavelength (e.g., 12.45mm). It is noted that Fig. 10a shows simulation results for a single wavelength (or frequency) for illustrating resonance effects. The method disclosed herein is performed for a set of frequencies and therefore for more than one frequency.

[0158] Fig. 10b shows results of the phase difference between the simulated S21 transmission phase and a linear phase for different separation distances between the device under test 110 and the antenna 122.

[0159] The phase results shown in Fig. 10b show the variation for different distances compared to an expected linear phase variation showing multiple resonance points, wherein the periodicity of the resonances in the phase difference also corresponds to half of the transmitted wavelength.

[0160] When performing measurements of the near field, pronounced resonance effects may decrease a measurement accuracy. In the example shown in Fig. 10a, the transmission of the S21 and the Sn parameters differs more at a distance of approximately 12mm than at a distance of 15mm, where resonances are less pronounced. Therefore, measurement accuracy can be improved by selecting distances, in which resonance effects are reduced or even avoided. The method disclosed herein comprising determining such an optimized (e.g. well-useable or even optimal or ideal) distance based on the first and second measurement data. The optimized distance may be determined using a plurality of the far field measurement results associated with different frequencies (e.g. of the set of frequencies) and corresponding near field measurement results (which are also associated with the different frequencies, e.g. of the set of frequencies). Determining the optimized distance may comprise averaging (e.g. without a weighting or with a weighting) a difference between a plurality of the far field measurement results associated with different frequencies (e.g. of the set of frequencies) and corresponding near field measurement results (which are also associated with the different frequencies, e.g. of the set of frequencies).

[0161] Now referencing Fig. 9, one example for determining the optimized distance comprises, in step comparing measured data for each distance x with reference far field data and find a distance x with a best correlation between the first and second measurement data. It is noted that Fig. 9 shows an example of a method for obtaining the second measurement and an example for determining the optimized distance. However, any other method for obtaining the second measurement disclosed herein may be combined with any example for determining the optimized distance disclosed herein.

[0162] The method described with reference to Fig. 9 may be used, for example, as algorithm for finding a distance between the device under test 110 and the antenna 112 of the testing arrangement 120 (e.g., an optimized or ideal DUT AiP to measurement antenna distance) from a minimum distance xmin to a maximum distance xmax with a Step size xstep. The x is, for example, a current distance between the device under test 1 10 (E.g., a DUT Aip) and the antenna 122 of the testing arrangement 120 (e.g., an ATE measurement antenna). A “golden device” (e.g., the device under test measured for reference data) may be measured, for example, previously or afterwards in the far field.

[0163] Fig. 1 1 a shows an example of first measurement data 970 and second measurement data 974. The example shown in Fig. 11 a depicts values of a radiated power Poutof a device under test (e.g., any device under test disclosed herein). Alternatively or additionally, any other metric (or value) disclosed herein may be used.

[0164] The first measurement data 970 comprise a first value 972a measured in the far field at a first frequency of a set of frequencies, which is depicted as a horizontal dished line. The first measurement data 970 comprise a second value 972b measured in the far field at a second frequency of the set of frequencies, which is depicted as a horizontal continuous line. The set of frequencies may comprise more than the first and second frequency. It is noted that the first and second values 972a, b are drawn as horizontal lines in order to facilitate comparison with values of the second measurement data 974 and are not to be understood as constant values for all distances.

[0165] The second measurement data 974 comprise a first set of values 976a-l (indicated with circles in Fig. 1 1 a) obtained for a plurality of distances (in the example of Fig. 1 1 a total of twelve distances) between the device under test 1 10 and the antenna 122 of the measurement arrangement 120 or associated (e.g., taking a rescaling into account) with the plurality of distances between the device under test 110 and the antenna 122 of the measurement arrangement 120 and measured at the first frequency of a set of frequencies.

[0166] The second measurement data 974 comprise a second set of values 978a-d (indicated with squares in Fig. 1 1 ) obtained for the plurality of distances (in the example of Fig. 11 a total of twelve distances) between the device under test 1 10 and the antenna 122 of the measurement arrangement 120 or associated (e.g., taking a rescaling into account) with the plurality of distances between the device under test 110 and the antenna 122 of the measurement arrangement 120 and measured at the second frequency of a set of frequencies.

[0167] The first and / or second measurement data 974 may comprise values that have been obtained by direct measurement or that are associated to values obtained by measurement. For example, the first and / second measurement data 974 may be rescaled (e.g., in order to take into account an attenuation at larger distances) or processed otherwise (e.g. filtered, denoised or compressed).

[0168] Fig. 11 b shows a selection of values from the first and second measurement data shown in Fig. 11 a. The selection of values allows describing the method disclosed herein with only two frequencies and two distances for easier understanding.

[0169] The second measurement data comprise a value 976g (shown as circles in Fig. 1 1 b) obtained for a first distance and a value 976i at a second distance between the device under test 122 and the antenna 122 of the measurement arrangement 120 or associated with the first and second distance between the device under test 1 10 and the antenna 122 of the measurement arrangement 120 measured at the first frequency.

[0170] The second measurement data comprise a value 978g (shown as squares in Fig. 11 b) obtained for the first distance and a value 978i at the second distance between the device under test 122 and the antenna 122 of the measurement arrangement 120 or associated with the first and second distance between the device under test 110 and the antenna 122 of the measurement arrangement 120 measured at the second frequency.

[0171] Determining the optimized distance may comprise comparing value 976g of the second measurement data (e.g. a value of a first set of values) obtained for the first distance (e.g. measurement data associated with the first frequency) with one or more corresponding values 972a of the first measurement data 970, to obtain a first comparison result. The first comparison result may describe a similarity between the second measurement data (e.g., value 976g) obtained for the first distance and the first measurement data 970. In the example shown in Fig. 11 b, the first comparison result is a difference 980g between the value 978g and the first value 972a measured in the far field at a first frequency. Alternatively, other similarity measures may be used such as a square root of the distance or a comparison with a (fixed or variable) threshold. It is noted that a corresponding value 972a of the first measurement data 970 is not limited to an identical frequency. One or more corresponding values 972a of the first measurement data 970 may be one or more closest frequencies or one or more frequencies within a threshold.

[0172] Determining the optimized distance may further comprise comparing value 976i of the second measurement data (e.g. a value of a second set of values) obtained for the second distance with one or more corresponding values 972a of the first measurement data, to obtain a second comparison result (e.g., a difference 980i).

[0173] Determining the optimized distance may comprise determining the optimized distance on the basis of the first comparison result and the second comparison result. For example, the optimized distance may be determined as the distance with the smallest comparison result. In the example shown in Fig. 11 b, the optimized distance may be determined as the distance associated with value 976g (or first comparison result 980g), because difference 980g of the first comparison result is smaller than the difference 980i of the second comparison result.

[0174] The example described above uses values of the second measurement data 974 obtained only the first frequency. The method may use values obtained for more than one frequency.

[0175] The method may comprise determining a first comparison result associated with the first distance (e.g., the difference 980g determined for first frequency and a difference 981 g determined for the second frequency) and the second distance (e.g., the difference 980i determined for the first frequency and a difference 981 i determined for the second frequency) determined from second measurement data 974 obtained for the first frequency and second frequency.

[0176] Determining the optimized distance may comprise determining the optimized distance on the basis of the first comparison result and the second comparison result. Using the example of the differences 980g, 980i, 981 g, 98i between the values of the second measurement data 974 and the first measurement result 972, for each of the first and second distance, a measure indicative of a combination of the respective differences (e.g., a sum, an arithmetic mean, a geometric mean or a harmonic mean of the differences) may be formed and the resulting measure for each distance may be compared. For example, the first comparison result may comprise a sum of the differences 980g and 978g and the second comparison result may comprise a sum of the difference 980i and 976i. In the example shown in Fig. 11 b, the sum of the differences 980g and 978g is smaller than sum of the difference 980i and 976i. Therefore, the distance associated with values 976g, 978g may be determined as the optimized distance.

[0177] In the example shown in Fig. 11 b, the optimized distance has been determined based on values of the second measurement data 974 that are associated with only two distances. Alternatively, more than two distances (e.g., three, four, five, or more) can be used. For example, in Fig. 1 1 a, the second measurement data 974 of all twelve distances may be used.

[0178] In the example shown in Figs. 11 a and b, the first and second measurement data are determined for only a first and second frequency. However, more than two frequencies (e.g., three, four, five, or more) may be used.

[0179] Fig. 12a shows sets 982a-l associated with the first and second measurement data of Fig. 11 a.

[0180] The second measurement data 974 may comprise a first set 982a of near field measurement result values associated with a first distance between the device under test 1 10 and the antenna 122 of the testing arrangement 120 (e.g. are obtained for the first distance between the device under test 1 10 and the antenna 122 of the testing arrangement 120). For example, the values of the first set 982a of near field measurement result values are associated with different frequencies (e.g. the first and second frequencies).

[0181] The second measurement data 974 comprise a second set 982b of near field measurement result values associated with a second distance between the device under test 1 10 and the antenna 122 of the testing arrangement 120 (e.g. are obtained for the second distance between the device under test 1 10 and the antenna 122 of the testing arrangement 120). For example, the values of the second set 982b of near field measurement result values are associated with the different frequencies (e.g. the first and second frequencies).

[0182] The values of the first set 982a of near field measurement results may correspond to the values of the second set 982b of near field measurement result values except for the fact that the values of the first set 982a of measurement result values are determined for the first distance and that the values of the second set 982b of near field measurement result values are determined for the second distance. As can be seen in Fig. 12a, the second measurement data 974 may comprise more than two sets 982. However, with reference to Fig. 12a, examples of the method will be described using only the first and second set 982a, b.

[0183] The optimized distance may be determined in dependence on deviations between the sets 982a, b of near field measurement result values and a (corresponding) set of far field measurement result values (which are included in the first measurement data). The set of far field measurement result values may be considered as reference far field data. The set of far field measurement result values may comprise for each frequency of the set of frequencies one or more values (wherein Fig. 12a exemplarily shows value 972a for the first frequency and value 972b for the second frequency).

[0184] The deviation may, for example, be determined as an unsigned (or absolute) deviation (e.g., a sum of absolute differences between the near field measurement result values and the far field measurement result values), a signed deviation (e.g., a sum of differences between the near field measurement result values and the far field measurement result values), a squared deviation (e.g., a sum of squares of differences between the near field measurement result values and the far field measurement result values). Alternatively or additionally, the optimized distance may be determined in dependence on a deviation between the sets 982a, b of near field measurement result values and a mean value of the sets 982a, b of near field measurement result values. Fig. 12b shows an example of deviations (indicated as triangles) determined for the sets 982a-l of Fig. 12a.

[0185] The deviation determined for the first set 982a is larger than for the second set 982b. Therefore, when only using the first and second sets 982a, b, the optimized distance may be the distance associated with the second set 982b due to its smaller deviation.

[0186] When using all twelve sets 982a-l, more distances are available for determining the optimized distance. In the example shown in Fig. 12b the deviation for the set 982I is the smallest of the sets 982a-l. Therefore, the distance associated with the set 982I may be determined as the optimized distance. However, other factors may be considered. For example, the deviations or values used to determine the deviations may be modified. For example, the deviations may be scaled according to the associated distance (e.g., deviation of sets 982a-l may be multiplied with a scaling factor dependent on the respective distance, e.g., if smaller or larger distances are preferred).

[0187] The optimized distance may be determined such that a difference between a far field measurement result and a corresponding near field measurement result is smaller than a predetermined maximum deviation for all frequencies of the set of frequencies, or wherein the optimized distance is determined such that a difference between a far field measurement result and a corresponding near field measurement result is smaller than or equal to a predetermined maximum deviation for all frequencies of the set of frequencies. If for a plurality of distances it is determined that the difference is smaller than (or equal to) the predetermined maximum deviation for all frequencies of the set of frequencies, the plurality of distances may be suitable for further testing. The plurality of distances may be output to a user (e.g., for selection of a distance). If for no distance it is determined that that the difference is smaller than (or equal to) the predetermined maximum deviation for all frequencies of the set of frequencies, an output may be generated indicating that no distance meets said requirement.

[0188] The optimized distance may be determined such that a near field measurement result or a difference between a far field measurement result and a corresponding near field measurement does not exhibit a resonance effect (e.g. beyond a predetermined maximum deviation) for all frequencies of the set of frequencies. A presence of a resonance effect may be recognized by a comparison of near field measurement results for a given frequency and for a plurality of distances with an average value of the near field measurement results for the given frequency and for the plurality of distances, wherein a deviation from the average value which is larger than a predetermined threshold value may be recognized as a resonance effect. The method may comprise avoiding a distance at which there is a significant resonance effect (e.g., exceeding a threshold) that significantly degrades a near field measurement result at at least one frequency of the set of frequencies.

[0189] The method may comprise determining one or more distances with a resonance effect. The method may comprise fitting near field measurement result of the same frequency to a comparison function (e.g. determined based on at least one of a pre-determined function and one or more values of the near field measurement result of the same frequency, and a mean value of one or more values of the near field measurement result of the same frequency) and determining distances at which near field measurement result meet a deviation criterion from the fitted near field measurement result such as an absolute or relative deviation. The method may comprise determining one or more periodic pattern in the near field measurement result (e.g., using at least one of a Fourier transformation and the wavelength used for the near field measurement result) and determining local extrema (e.g., local maxima and / or local minima). Determining one or more distances with a resonance effect may be based on a value type of the near field measurement result. For example, in measurements of the DUT radiated power, resonance effects may be identified as local minima, whereas in measurements of the DUT reflected power, resonance effects may be identified as local maxima. For example, in measurements of a phase difference, resonance effects may be identified a maximum or minimum with the largest absolute value (e.g., within a determined pattern period).

[0190] The method may comprise assigning to one or more distances each a resonance indicator related to a resonance effect. The method may comprise assigning no resonance indicator to a distance that does not exhibit a resonance effect or assigning to a distance that does not exhibit a resonance effect a resonance indicator that indicates that the distance does not exhibit a resonance effect. The resonance indicator may indicate that a resonance has been determined for the assigned distance. The resonance indicator may indicate a measure (or degree) of the resonance effect (e.g., based on a deviation or absolute value of the near field measurement result). The method may comprise determining the optimized distance as a distance with no resonance effect or the least resonance effect (e.g., based on resonance indicator for each of the distances, e.g., based on a sum of the measure (or degree) of the resonance effect for each distance).

[0191] The method described above allows determining an optimized distance for testing a device under test 1 10. The optimized distance may subsequently be used to test further device under test (e.g., devices under test of the same (or at least similar) type, e.g., devices under test that have the same (or at least similar) near field and / or far field).

[0192] Fig. 13 shows a flow diagram 1390 of an exemplary method for testing a plurality of devices under test. The method may be used with any device under test 110 disclosed herein and any testing arrangement disclosed herein.

[0193] The method comprises, in step 1391 , determining an optimized distance between the device under test 1 10 and an antenna 122 of the testing arrangement 120 using a method as described herein, wherein the optimized distance is determined using a production-test test program, which is repeated one or more times with a modified distance between the device under test 1 10 and the antenna 122 of the testing arrangement 120, in order to determine the optimized distance, or wherein the optimized distance is determined using a produc- tions-test test program, which is supplemented by a functionality to effect a repetition (e.g. of a test flow) and a modification of a distance between the device under test and the antenna of the testing arrangement, in order to determine the optimized distance; and

[0194] The method comprises, in step 1392, testing a plurality of devices under test using the production test program, wherein a distance between the device under test is kept constant at the previously determined optimized distance.

[0195] Implementation alternatives

[0196] Although some aspects have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus.

[0197] Depending on certain implementation requirements, embodiments of the invention may be implemented in hardware or in software. The implementation may be performed using a digital storage medium, for example a floppy disk, a DVD, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed.

[0198] Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0199] Generally, embodiments of the present invention may be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer. The program code may for example be stored on a machine readable carrier.

[0200] Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier.

[0201] In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0202] A further embodiment of the inventive methods is, therefore, a data carrier (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein. The data carrier, the digital storage medium or the recorded medium are typically tangible and / or non-transitionary.

[0203] A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the internet.

[0204] A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein. A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.

[0205] A further embodiment according to the invention comprises an apparatus or a system configured to transfer (for example, electronically or optically) a computer program for performing one of the methods described herein to a receiver. The receiver may, for example, be a computer, a mobile device, a memory device or the like. The apparatus or system may, for example, comprise a file server for transferring the computer program to the receiver.

[0206] In some embodiments, a programmable logic device (for example a field programmable gate array) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods are preferably performed by any hardware apparatus.

[0207] The apparatus described herein may be implemented using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

[0208] The apparatus described herein, or any components of the apparatus described herein, may be implemented at least partially in hardware and / or in software.

[0209] The methods described herein may be performed using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

[0210] The above described embodiments are merely illustrative for the principles of the present invention. It is understood that modifications and variations of the arrangements and the details described herein will be apparent to others skilled in the art. It is the intent, therefore, to be limited only by the scope of the impending patent claims and not by the specific details presented by way of description and explanation of the embodiments herein.

Claims

Claims1 . A method (800) for determining an optimized distance between a device under test (1 10; 310; 510; 1310a; 1310b) and an antenna (122; 322; 522) of a testing arrangement (120; 520), the method comprisingObtaining (802) first measurement data (970), wherein the first measurement data (970) represent a plurality of far field measurement results characterizing the device under test (110; 310; 510; 1310a; 1310b) for a set of frequencies, or wherein the first measurement data (970) are based on a plurality of far field measurement results characterizing the device under test (1 10; 310; 510; 1310a; 1310b) for a set of frequencies;Obtaining (804) second measurement data (974), wherein the second measurement data (974) represent a plurality of near field measurement results characterizing the device under test (1 10; 310; 510; 1310a; 1310b) for the set of frequencies, or wherein the second measurement data (974) are based on a plurality of near field measurement results characterizing the device under test (1 10; 310; 510; 1310a; 1310b) for the set of frequencies; wherein at least two of the near field measurement results are captured at different distances between the device under test (1 10; 310; 510; 1310a; 1310b) and an antenna (122; 322; 522) of the testing arrangement (120; 520); and determining (806) the optimized distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520) based on the first and second measurement data (974).

2. The method (800) according to claim 1 , wherein determining the optimized distance comprises comparing one or more values of the second measurement data (974) obtained for a first distance between the device under test (110; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the measurement arrangement or associated with a first distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322;measurement data (970), to obtain a first comparison result; and comparing one or more values of the second measurement data (974) obtained for a second distance between the device under test (110; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the measurement arrangement or associated with a second distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the measurement arrangement with one or more corresponding values of the first measurement data (970), to obtain a second comparison result; and determining the optimized distance on the basis of the first comparison result and the second comparison result.

3. The method (800) according to claim 2, wherein the first and second measurement data (974), or at least one or more values of the first and second measurement data (974), are obtained based on a wireless transmission of a signal by the device under test (1 10; 310; 510; 1310a; 1310b) or are obtained when the device under test (110; 310; 510; 1310a; 1310b) is wirelessly transmitting a signal.

4. The method (800) according to claim 2 or 3, wherein the one or more values of the first measurement data (970) comprise at least one of a power value, a gain value, a gain step value, a gain compression value, a phase shift value, a gain flatness value, an error vector magnitude value, an isolation value, a spurs value, and an adjacent channel power ratio value; and wherein the one or more values of the second measurement data (974) comprise at least one of a power value, a gain value, a gain step value, a gain compression value, a phase shift value, a gain flatness value, an error vector magnitude value, an isolation value, a spurs value, and an adjacent channel power ratio value.

5. The method (800) according to one of claims 2, 3, or 4, wherein the first and second measurement data (974), or at least one or more values of the first and second measurement data (974), are obtained based on a wireless reception of a signal by the device under test (1 10; 310; 510; 1310a; 1310b), or are obtained when the device under test (110; 310; 510; 1310a; 1310b) is wirelessly receiving a signal.

6. The method (800) according to one of claims 2 to 5, wherein the one or more values of the first measurement data (970) comprise at least one of a power, a gain value, a gain step value, a third-order intercept point value, a phase shift value, a gain flatness value, an error vector magnitude value, an isolation value, and a noise figure value, and wherein the one or more values of the second measurement data (974) comprise at least one of a power value, a gain value, a third-order intercept point value, a phase shift value, a gain flatness value , an error vector magnitude value, an isolation value, and a noise figure value.

7. The method (800) according to one of claims 2 to 6, wherein the second measurement data (974) comprise a first set (982a) of near field measurement result values associated with a first distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520), and wherein the second measurement data (974) comprise a second set (982b) of near field measurement result values associated with a second distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520),wherein the optimized distance is determined in dependence on deviations between the sets of near field measurement result values and a set of far field measurement result values.

8. The method (800) according to one of claims 1 to 7, wherein the optimized distance is determined using a plurality of the far field measurement results associated with different frequencies and corresponding near field measurement results.

9. The method (800) according to one of claims 1 to 8, wherein determining the optimized distance comprises averaging a difference between a plurality of the far field measurement results associated with different frequencies and corresponding near field measurement results.

10. The method (800) according to one of claims 1 to 9, wherein the optimized distance is determined such that a difference between a far field measurement result and a corresponding near field measurement result is smaller than a predetermined maximum deviation for all frequencies of the set of frequencies, or wherein the optimized distance is determined such that a difference between a far field measurement result and a corresponding near field measurement result is smaller than or equal to a predetermined maximum deviation for all frequencies of the set of frequencies.11 . The method (800) according to one of claims 1 to 10, wherein the optimized distance is determined such that a near field measurement result or a difference between a far field measurement result and a corresponding near field measurement does not exhibit a resonance effect for all frequencies of the set of frequencies.

12. The method (800) according to one of claims 1 to 11 , wherein the method comprises determining, as the optimized distance, a single distance which is used for all frequencies of the set of frequencies.

13. The method (800) according to one of claims 1 to 12, wherein the method comprises using a production-test test program for obtaining the first measurement data (970).

14. The method (800) according to one of claims 1 to 13, wherein the method comprises executing a production-test program, which controls a testing of the device under test (1 10; 310; 510; 1310a; 1310b) for a plurality of test frequencies, for a plurality of distances, to thereby obtain the second measurement data (974).

15. The method (800) according to one of claims 1 to 14, wherein the method comprises using a production-test test program, which is repeated one or more times with modified distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520), in order to determine the optimized distance, or wherein the method comprises using a production-test test program, which is supplemented by a functionality to effect a repetition and a modification of a distance between the device under test (110; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520), in order to determine the optimized distance.

16. The method (800) according to one of claim 1 to 15,wherein the method comprises varying a distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520) between measurements that are used to obtain the near field measurement result.

17. The method (800) according to one of claims 1 to 16, wherein the method comprises step-wisely varying the distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520).

18. The method (800) according to one of claims 1 to 17, wherein the method comprises determining which subset of the second measurement data (974), out of a plurality of subsets of the second measurement data (974) associated with different distances, comprises a maximum similarity to the first measurement data (970), and wherein the method comprises determining the optimized distance based thereon.

19. The method (800) according to any of the claims 1 to 18, further comprising determining, for each frequency of the set of frequencies, distances with a standing wave behaviour, wherein the optimized distance is determined from distances with no or the least standing wave behaviour.

20. The method according to any of the preceding claims, further comprising generating a control signal for controlling movements of a stage supporting the antenna (122; 322; 522) of the testing arrangement (120; 520), wherein the control signal causes the stage to move to at least two of the different distances.21 . A method (1390) for testing a plurality of devices under test,wherein the method comprises determining an optimized distance between the device under test (1 10; 310; 510; 131 Oa; 131 Ob) and an antenna (122; 322; 522) of the testing arrangement (120; 520) using a method according to one of claims 1 to 20, wherein the optimized distance is determined using a production-test test program, which is repeated one or more times with a modified distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520), in order to determine the optimized distance, or wherein the optimized distance is determined using a productions-test test program, which is supplemented by a functionality to effect a repetition and a modification of a distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520), in order to determine the optimized distance; and wherein the method comprises testing a plurality of devices under test using the production test program, wherein a distance between the device under test (110; 310; 510; 1310a; 1310b) is kept constant at the previously determined optimized distance.

22. A computer program for performing the method of one of claims 1 to 21 , when the computer program is executed on a computer.

23. A testing arrangement (120; 520) for determining an optimized distance between a device under test (110; 310; 510; 1310a; 1310b) and an antenna (122; 322; 522) of a testing device (140; 540), wherein the testing arrangement (120; 520) is configured to obtain first measurement data (970), wherein the first measurement data (970) represent a plurality of far field measurement results characterizing the device under test (1 10; 310; 510; 1310a; 1310b) for a set of frequencies, or wherein the first measurement data (970) are based on a plurality of far field measurement results characterizing the device under test (110; 310; 510; 1310a; 1310b) for a set of frequencies;wherein the testing arrangement (120; 520) is configured to obtain second measurement data (974) wherein the second measurement data (974) represent a plurality of near field measurement results characterizing the device under test (110; 310; 510; 1310a; 1310b) for the set of frequencies, or wherein the second measurement data (974) are based on a plurality of near field measurement results characterizing the device under test (1 10; 310; 510; 1310a; 1310b) for the set of frequencies; wherein at least two of the near field measurement results are captured at different distances between the device under test (1 10; 310; 510; 1310a; 1310b) and an antenna (122; 322; 522) of the testing arrangement (120; 520); and wherein the testing arrangement (120; 520) is configured to determine the optimized distance between the device under test (1 10; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520) based on the first and second measurement data (974).

24. The testing arrangement (120; 520) according to claim 23, further comprising a device socket (128) configured to receive the device under test (110; 310; 510; 1310a; 1310b); wherein the testing arrangement (120; 520) is configured to perform a plurality of tests when the device under test (1 10; 310; 510; 1310a; 1310b) is arranged in the device socket (128), in order to obtain the near field measurement results for the set of frequencies, wherein at least two of the tests are performed at different distances between the device under test (110; 310; 510; 1310a; 1310b) and the antenna (122; 322; 522) of the testing arrangement (120; 520), in order to obtain near field measurement results for the at least two different distances.

25. The testing arrangement (120; 520) according to claim 23 or 24, further comprisinga stage supporting the antenna (122; 322; 522) of the testing arrangement (120; 520) and configured to move to at least two different distances relative to the device socket (128).

26. The testing arrangement (120; 520) according to any of claims 23 to 25, further comprising a far field testing device (140; 540) configured to perform a test of the device under test (1 10; 310; 510; 1310a; 1310b) at the set of frequencies in a far field condition, in order to obtain the first measurement data (970).

27. The testing arrangement (120; 520) according to any of the claims 23 to 26, further comprising a data interface configured to receive the first measurement data (970) and / or the second measurement data (974).

28. The testing arrangement (120; 520) according to any of the claims 23 to 27, wherein the testing arrangement (120; 520) is configured to perform a method according to any of the claims 1 to 21 .

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