A device under test socket structure with a pusher surrounded with an electromagnetic absorber and a test arrangement or an automated test equipment comprising the same

Abstract

An embodiment according to the present application is a device under test socket structure (100, 260, 620, 1510, 1520) comprising a pusher (110, 210, 310, 510, 1310, 1785, 1850, 2030, 2110) and a DUT socket (120,220, 320, 420, 520, 1020, 1350, 1820, 1910). The DUT socket has a receiving section (130, 230, 330, 430, 1030) configured to receive a DUT (150, 250, 350, 450, 550, 1620, 1720, 2150). The pusher is configured to push the DUT towards the receiving section or to push the DUT into the receiving section. The pusher is at least partially surrounded by an electromagnetic absorber.

Description

[0001] A device under test socket structure with a pusher surrounded with an electromagnetic absorber and a test arrangement or an automated test equipment comprising the same

[0002] Description

[0003] Technical field

[0004] Embodiments according to the invention are related to an over-the-air device under test socket structure with a pusher surrounded with an electro-magnetic absorber. Embodiments of the present invention are further related to a test arrangement or an automated test equipment comprising the same. Embodiments according to the invention are related to how to add structures made using an radio frequency (RF) absorber material to near-field over the air sockets to improve the near-field measurement performance and also site to site isolation in multi-site testing. Embodiments according to the invention are related to an automated test equipment near-field socket absorber.

[0005] Background

[0006] In a production environment multiple device are produced and tested via the same machine over several production lines within the same production hall. With the spreading of the near-field over-the-air (OTA) testing method the surrounding of the OTA test area becomes polluted by the electromagnetic signals used in the near-field OTA testing, which reflects back from the nearby surfaces or conductive surface, negatively affecting the test results and / or the accuracy of the test results. Reducing the electromagnetic pollution of the near- field OTA testing would be beneficial, as it improves the near-field measurement performance and the site to site isolation in multi-site testing.

[0007] Fig.6 of US 11,496,227 B2 discloses a sheet-like radio wave absorber arranged along the inner wall of the pusher. The radio wave absorber has a rectangular tubular shape along the shape of the pusher and is allowed to surround the device antenna of the DUT. The radio wave absorber on the inner wall of the pusher reduces the reflection of radio waves inside the pusher during the OTA test. This allows to perform the OTA test in the near-field with higher accuracy. As a material constituting the radio wave absorber, the same material as that of the material constituting the attenuation member can be used. However the pusher is just a frame, so that the pushing force is not distributed evenly on the DUT, resulting in mechanical stress within the DUT. An evenly distributed pushing force would improve the stability of the DUT within the socket and simultaneously reduce the mechanical stress of the DUT.

[0008] Therefore, there is need for is providing a socket structure which reduces the electromagnetic pollution of a near-field OTA testing method in order to improve the near-field measurement performance and / or the site to site isolation in multi-site testing.

[0009] Summary of the invention

[0010] An embodiment of the present invention relates to a device under test (DUT) socket structure, e.g. for over-the-air (OTA) testing, or e.g. for near field over-the-air testing. The DUT socket structure comprises a pusher and a DUT socket, having a receiving (or accepting) section configured to receive the DUT.

[0011] The pusher is configured to push the DUT towards the receiving section (e.g. towards a recess for accepting the DUT, e.g. towards a contact structure for contacting the DUT, e.g. towards a DUT position within the DUT socket) or to push the DUT into the DUT position (e.g. into a recess for accepting the DUT, e.g. into a contact structure for contacting the DUT, in order to establish a better contact e.g. into a DUT position within the DUT socket, e.g. by using a pushing surface of the pusher).

[0012] The pusher is at least partially surrounded, e.g. in a region of its lateral surface, by an electromagnetic absorber, e.g. an RF absorber (for example, by an (dedicated) electromagnetic absorber specifically (e.g. solely, or only) surrounding the pusher (or a part of the pusher) but not enclosing the overall test arrangement and not enclosing the rest of the device under test socket; for example, surrounded in a way to provide a propagation tunnel surrounded by the electromagnetic absorber between the DUT position and the measurement antenna structure, at least over a part of the propagation path between the measurement antenna structure and the DUT position).

[0013] For example, the electromagnetic absorber is arranged to avoid an un-attenuated reflection of a wave, propagating from the device under test position or propagating from a test antenna of the DUT, at a conductive structure arranged at a distance from an axis of the pusher or at a dielectric structure arranged at a distance from an axis of the pusher (e.g. at a support structure of the DUT socket structure).

[0014] For example, the electromagnetic absorber is configured to absorb radiation which leaves the pusher in a direction tilted with respect to an axis of the pusher.

[0015] For example, the electromagnetic absorber is configured to absorb radiation which propagates from the device under test position in a direction which deviates from a direction towards a measurement antenna structure.

[0016] For example, the electromagnetic absorber is configured to absorb radiation which propagates from a measurement antenna structure in a direction which deviates from a direction towards the device under test position.

[0017] For example, the electromagnetic absorber may be manufactured using a molding technique and / or using a three-dimensional printing technique.

[0018] For example, the electromagnetic absorber may comprise a plurality of individual absorber sections that are assembled together.

[0019] For example, the pusher may comprise a pushing surface, which is configured to contact with the DUT and to push the DUT towards the receiving section and / or which is configured to push into the DUT towards the receiving section or the accepting section or the recess of the DUT socket.

[0020] The electromagnetic absorber surrounding the pusher allows the pusher to be a solid block with a pushing surface. The pushing surface may be matching with the DUT. Alternatively the pusher may accept an exchangeable cap having a pushing surface matching with the DUT. Thus, the pusher could use its entire surface, the pushing surface for pushing the DUT into or towards the receiving section, resulting in a substantially even distribution of the pushing force, while reducing the electromagnetic pollution of the surroundings, improving the near-field measurement performance and the site to site isolation in multi-site testing. That is, the DUT socket structure comprises a DUT socket with a receiving section and a pusher surrounded by an electromagnetic absorber. The pusher is pushing the DUT into or towards the receiving section during an OTA test or during a near field OTA test. The electromagnetic absorber surrounding the pusher absorbs radiations or electromagnetic waves or their reflections used in the OTA test, which would otherwise pollute the surroundings or affect the OTA test itself. Thus it improves the near-field measurement performance and the site to site isolation in multi-site testing.

[0021] For example, the absorber is part of the socket structure. For example, the absorber and the pusher is on a lid, or for example, the absorber and the pusher are part of a handler change kit arm in a high volume production environment.

[0022] In other words, it depends on the application specifics whether the absorber belongs to the DUT socket. In some embodiments, the absorber may be part of the socket structure, i.e. on the lid with the pusher, in some cases it (e.g. the absorber) might be part of the handler change kit arm in high volume production or it (e.g. the absorber) might be part of the load board for more complex AiP modules like the L-shape type.

[0023] In a preferred embodiment, the DUT socket comprises one or more side walls surrounding the receiving section (e.g. in a lower, fixed portion of the DUT socket, e.g. in a portion of the DUT socket which remains attached to a load board when the DUT socket is opened for a device under test change, e.g. a plurality of side walls, e.g. in case of a substantially rectangular or substantially quadratic opening surrounding the DUT position, e.g. a substantially circular sidewall, e.g. in case of a substantially circular opening surrounding the DUT position).

[0024] A surface of the one or more side walls facing towards the receiving section is at least partially covered by an electromagnetic absorber.

[0025] For example, the electromagnetic absorber covering the side walls facing towards the receiving section may be arranged to remain attached to said side walls when the DUT socket is opened for a device under test change, e.g. the electromagnetic absorber covering the side walls facing towards the receiving section may be arranged to surround the pusher when the socket is closed. i The DUT socket may for example comprise a plurality of side walls, in case of a substantially polygonal, such as rectangular or substantially quadratic opening surrounding the receiving section. The DUT socket may for example comprise a single, substantially circular or elliptical sidewall, in case of a substantially circular or elliptical opening surrounding the receiving section.

[0026] For example, the electromagnetic absorber covering the side walls facing towards the receiving section may be arranged to surround the pusher when the pusher is pushing the device under test towards the DUT position or into the device under test position.

[0027] For example, the electromagnetic absorber covering the side walls facing towards the receiving section may be arranged to surround a spatial area in which the pusher is moveable. For example the electromagnetic absorber covering the side walls facing towards the receiving section may be arranged to surround a spatial area through which the device under test is inserted into the device under test position or through which the device under test is extracted from the device under test position.

[0028] That is, the electromagnetic absorber covering the side walls are surrounding the receiving section in order to absorb the side radiations of the DUT, when the DUT is placed in the receiving section, reducing the electromagnetic pollution in the plane or environment of the receiving section as well, in order to improve the near-field measurement performance and the site to site isolation in multi-site testing.

[0029] The electromagnetic absorber covering the side walls facing towards the receiving section may be arranged to remain attached to said side walls when the DUT socket is opened for a DUT change, while may be arranged to surround the pusher when the socket is closed or when the pusher is pushing the DUT towards the receiving section or into the receiving section.

[0030] In a preferred embodiment, a lateral surface of the pusher is fully surrounded (e.g. surrounded in all directions; e.g. surrounded over 360 degrees; e.g. surrounded in an enclosing manner) by the electromagnetic absorber at least over a part of a longitudinal extension of the pusher. For example, the longitudinal extension of the pusher may be an extension along a pushing direction, and / or for example, the longitudinal extension of the pusher may be an extension along an axis of the pusher.

[0031] For example, the pusher is not surrounded by the electromagnetic absorber over its full longitudinal extension; for example, a longitudinal extension of the electromagnetic absorber is shorter than a longitudinal extension of the pusher, for example such that a portion of the pusher at a pushing end is not surrounded by the electromagnetic absorber.

[0032] For example, at least a part of the electromagnetic absorber may be configured to be moveable together with the pusher when the DUT socket is opened for a device under test change.

[0033] For example, at least a part of the electromagnetic absorber may be configured to remain in a fixed positional relationship with the device under test position when the DUT socket is opened for a device under test change.

[0034] For example, at least a first part of the electromagnetic absorber may be configured to be moveable together with the pusher while the pusher is not surrounded by the electromagnetic absorber over its full longitudinal extension, and for example, at least a second part of the electromagnetic absorber may be configured to remain in a fixed positional relationship with the receiving section, resulting a gap between the first and second part of the electromagnetic absorber, so that the first part and the second part of the electromagnetic absorber are non-touching.

[0035] That is, the pusher or both the pusher and the receiving section is / are surrounded by the electromagnetic absorber in every lateral direction in order to protect the surrounding of the OTA test area in every direction. Moreover the length of the pusher may be longer than the length of the tubular electromagnetic absorber in order to establish a protecting gap, protecting the electromagnetic absorber from damages, in order to improve the longevity of the electromagnetic absorber. Further, the protecting gap may be established by having a gap between the electromagnetic absorber surrounding the pusher and the electromagnetic absorber covering the side walls of the DUT socket. In a preferred embodiment, the DUT socket comprises a plurality of side walls surrounding the receiving section, wherein the side walls decline towards the receiving section, e.g. to help a picking machine to position the DUT correctly.

[0036] For example, the declined sidewalls may not be covered by an electromagnetic absorber, e.g. to allow the device under test to slide into the device under test position.

[0037] For example, a longitudinal extension of the electromagnetic absorber surrounding the pusher is shorter than a longitudinal extension of the pusher, for example such that a portion of the pusher at a pushing end, which intrudes into a spatial area surrounded by the declined side walls, is not surrounded by the electromagnetic absorber.

[0038] For example the electromagnetic absorber surrounding the pusher and the declined side walls are non-touching, in order to improve the longevity of the electromagnetic absorber.

[0039] In a preferred embodiment, a surface of the electromagnetic absorber facing towards the pusher comprises a plurality of pyramid-like structures, e.g. pyramids or truncated pyramids, or cone-like structures, e.g. cones or truncated cones, e.g. comprising (or made of) electro- magnetically absorbing material.

[0040] The electromagnetic absorber or the RF absorber is designed with a specific shape to work in a near-field socket or DUT socket.

[0041] A surface comprising pyramid-like and / or cone-like structures directed at the pusher and / or at the receiving section, made of electromagnetically absorbing material improves the absorbance of the electromagnetic absorber.

[0042] In a preferred embodiment a height of the pyramid-like structures or cone-like structures is within a range between 0.1 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket) and 0.4 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket, wherein the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket).

[0043] Alternatively, the height of the pyramid-like structures or cone-like structures is within a range between 0.2 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket) and 0.3 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket) For example, the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket.

[0044] Choosing the right height of the pyramid-like or cone-like structures results in optimizing or rather maximizing the absorbance of the electromagnetic absorber.

[0045] In a preferred embodiment, an area of the base of the pyramid-like structures or of the conelike structures is within a range of 0.2-0.4 times the square of the wavelength at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket). For example, the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket).

[0046] Choosing the right area of the base of the pyramid-like or of the cone-like structures results in optimizing or rather maximizing the absorbance of the electromagnetic absorber.

[0047] In a preferred embodiment the electromagnetic absorber is arranged to surround a portion of the pusher, e.g. a part of an axial (e.g. longitudinal) extension of the pusher, with a spacing in between the electromagnetic absorber and the pusher.

[0048] For example, such that the electromagnetic absorber is not directly adjacent to the pusher.

[0049] For example, such that there is a spacing between the electromagnetic absorber and the pusher which locally varies by more than 50 percent, or even by more than 100percent. In a preferred embodiment, in a portion in which the electromagnetic absorber surrounds the pusher with a spacing in between, the distance between the electromagnetic absorber and the pusher is within a range between 0.2 times a wavelength, e.g. a tree-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the- air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket) and 0.8 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket). For example, the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket.

[0050] Alternatively, in a portion in which the electromagnetic absorber surrounds the pusher with a spacing in between, the distance between the electromagnetic absorber and the pusher is within a range between 0.1 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket) and 0.6 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket). For example, the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket.

[0051] A distance between the pusher and the electromagnetic absorber has been found to be advantageous, both mechanically and electromagnetically, but it has been found that it is advantageous to keep the space between the pusher and the electromagnetic absorber tight, so the production of the inventive DUT socket structure is minimally altered compared to a non-inventive DUT socket structure. That is, the electromagnetic absorber may even fit into a non-inventive DUT socket structure.

[0052] In a preferred embodiment the electromagnetic absorber is arranged between the pusher and a positioning structure of the DUT socket structure (e.g. a positioning structure which provides for an alignment, e.g. a lateral alignment, of a moveable portion of the DUT socket structure, e.g. an upper portion of the DUT socket structure comprising a measurement antenna and the pusher, e.g. with a spacing between an outer boundary of the electromagnetic absorber and the positioning structure). Alternatively or additionally, the electromagnetic absorber is arranged between the pusher and a fixing structure of the DUT socket structure (e.g. a fixing structure which fixes a moveable portion of the DUT socket structure, e.g. an upper portion of the DUT socket structure comprising a measurement antenna and the pusher) to a stationary portion of the DUT socket structure (e.g. a lower portion of the DUT socket structure comprising the device under test position, e.g. with a spacing between the electromagnetic absorber and the fixing structure).

[0053] Alternatively or additionally, the electromagnetic absorber is arranged between the pusher and a waveguide structure of the DUT socket structure (e.g. a waveguide structure which couples a moveable portion of the DUT socket structure, e.g. an upper portion of the DUT socket structure comprising a measurement antenna and the pusher, to a signal generator and / or to a signal receiver, e.g. with a spacing between the electromagnetic absorber and the waveguide structure).

[0054] An electromagnetic absorber covering the pusher (e.g. in a lateral direction, or on a surface opposing the pushing surface), eliminates or at least reduces the reflection of the radiation from the surface of the positioning structure or from the surface of the fixing structure or from the surface of the waveguide structure and thus further reducing the electromagnetic pollution of the surroundings, and improves the near-field measurement performance and the site to site isolation in multi-site testing.

[0055] According to a preferred embodiment a test arrangement comprises a DUT socket structure or an above discussed DUT socket structure, and a measurement antenna structure, wherein the pusher is arranged between the measurement antenna structure and the receiving section, e.g. such that there is an electromagnetic propagation path between the measurement antenna structure and the DUT position through the pusher.

[0056] For example, a propagation path or tunnel is provided through or within the pusher between the receiving section and the measurement antenna structure, which is surrounded at least over a part of the propagation path by the electromagnetic absorber.

[0057] For example, the electromagnetic absorber is configured to absorb radiation which propagates from the receiving section in a direction which deviates from a direction towards the measurement antenna. For example, the electromagnetic absorber is configured to absorb radiation which propagates from a measurement antenna in a direction which deviates from a direction towards the receiving section.

[0058] The measurement arrangement comprises a measurement antenna structure, such that the measurement antenna structure is as close to the receiving section as possible. The shorter the propagation path between the measurement antenna structure and the receiving section, the less energy is required to transmit a signal between the two. Also, a shorter distance between the measurement antenna structure and the receiving section reduces the amount of radiation that could potentially deviate from the propagation path. Moreover, a relatively small implementation may satisfy mechanical requirements and boundary conditions.

[0059] In a preferred embodiment the test arrangement comprises a further electromagnetic absorber portion with an opening. The further electromagnetic absorber portion is arranged to at least partially cover a surface of a conductive structure comprising the measurement antenna structure or carrying the measurement antenna structure (for example, to act as an electromagnetically absorbing interposer between the pusher and the conductive structure comprising the antenna structure or carrying the antenna structure).

[0060] For example, an environment of the antenna structure is exempt in the further electromagnetic absorber, e.g. in the form of the opening.

[0061] For example, the surface of the conductive structure is facing towards the receiving section.

[0062] The further electromagnetic absorber portion is arranged between the conductive structure and a portion of a surface of the pusher, such that the opening is located on an electromagnetic propagation path between the measurement antenna structure and the receiving section (for example, such that the opening allows an electromagnetic propagation between the measurement antenna structure and the DUT position through the pusher).

[0063] For example, the further electromagnetic absorber portion with an opening is arranged between a conductive structure, comprising or carrying the measurement antenna structure, and a portion of a surface of the pusher, so that the opening of the further electromagnetic absorber portion is located on an electromagnetic propagation path between the measurement antenna structure and the receiving section. The surface of the conductive structure is facing towards the receiving section. The further electromagnetic absorber portion is arranged to at least partially cover a surface of a conductive structure, e.g. to act as an elec- tromagnetically absorbing interposer between the pusher and the conductive structure comprising or carrying the antenna structure.

[0064] A further electromagnetic absorber portion with an opening arranged between the conductive structure and the pusher eliminates or at least reduces the reflections of the radiation on the surface of the conductive structure comprising or carrying the antenna structure, while not absorbing the measurement signals transmitted along the propagation path between the measurement antenna structure and the receiving section through the opening of the further electromagnetic absorber portion. Thus, the electromagnetic pollution of the surroundings is reduced further to improve the near-field measurement performance and the site to site isolation in multi-site testing, while the measurement is not hindered by the usage of the further electromagnetic absorber portion.

[0065] In a preferred embodiment the pusher comprises a widening at a longitudinal portion near to the measurement antenna structure (e.g. in such a manner that a portion of the pusher adjacent to the measurement antenna structure is widened, e.g. comprises a larger cross- sectional area in a plane perpendicular to the axis of the pusher, when compared to a portion of the pusher that is adjacent to the device under test position)

[0066] A surface on the DUT side of the widening, e.g. a surface that is substantially perpendicular to the propagation path, is covered by an electromagnetic absorber portion.

[0067] For example, such that said electromagnetic absorber portion is in between the DUT-sided surface of the widened portion of the pusher and a hollow portion between the pusher and an outer portion of the electromagnetic absorber surrounding the pusher with a spacing in between.

[0068] For example, the widening covered by an electromagnetic absorber portion comprises a larger cross-sectional area in a plane perpendicular to the axis of the pusher when compared to a portion of the pusher that is adjacent to the receiving section. For example, the electromagnetic absorber portion extends in a longitudinal direction from the receiving section-sided surface of the widened portion of the pusher to the electromagnetic absorber, while extends in a lateral or in a radial direction, depending on whether the base of pusher is a polygon or round, from the pusher to an outer portion of the electromagnetic absorber surrounding the pusher with a spacing in between.

[0069] If the pusher comprises a widening an electromagnetic absorber portion covering the widening extending from the pusher to the electromagnetic absorber surrounding the pusher this eliminates or at least reduces the radiation taking a different path from the propagation path between the measurement antenna structure and the receiving section, further reducing the electromagnetic pollution of the surroundings, e.g. to improve the near-field measurement performance and the site to site isolation in multi-site testing, while not hindering or blocking the propagation path.

[0070] An embodiment creates a test cell comprising a plurality of test arrangements as disclosed herein, wherein, for example, the electromagnetic absorber is configured to at least partially absorb radiation propagating from a test site to another test site.

[0071] An embodiment creates an automated test equipment comprising a test cell a disclosed herein, or a test arrangement as disclosed herein.

[0072] In the following further embodiments will be described which can be used separately from the above discussed embodiments. However, any of the features, functionalities and details described in the following may optionally be introduced into any other embodiments disclosed herein, e.g. into any of the embodiments described above. Moreover, any of the features, functionalities and details described above may optionally be introduced into any of the embodiments described below.

[0073] An embodiment creates a test arrangement (e.g. for OTA testing, e.g. for near field over- the-air testing) comprising a DUT socket placed on a loadboard, e.g. a test fixture, having a receiving (or accepting) section configured to accept the DUT, e.g. a non-planar DUT, and a measurement antenna structure arranged in a way that a propagation path between the receiving section and the measurement antenna structure is tilted with respect to a plane of a load board, e.g. a load board to which the DUT socket is attached, by no more than 45 degrees.

[0074] For example, in a preferred embodiment, the measurement antenna structure is arranged in a way that the propagation path between the receiving section and the measurement antenna structure is tilted with respect to the plane of the load board by no more than 10 degrees.

[0075] For example, in a preferred embodiment, the measurement antenna structure is arranged in a way that the propagation path between the receiving section and the measurement antenna structure is at least substantially parallel to the plane of the loadboard.

[0076] For example, the propagation path between the receiving section and the measurement antenna structure is at least partially surrounded by an electromagnetic absorber.

[0077] For example, by an (dedicated) electromagnetic absorber specifically, e.g. solely, or only, surrounding the propagation path or a part of the propagation path but not enclosing the overall test arrangement and not enclosing the DUT and not enclosing the DUT socket.

[0078] For example, surrounded in a way to provide a propagation tunnel surrounded by the electromagnetic absorber between the receiving section and the measurement antenna structure, at least over a part of the propagation path between the measurement antenna structure and the receiving section.

[0079] For example, the electromagnetic absorber may be manufactured using a molding technique and / or using a three-dimensional printing technique.

[0080] For example, the electromagnetic absorber may comprise a plurality of individual absorber sections that are assembled together.

[0081] That is, the test arrangement comprises a DUT socket and a measurement antenna structure. The propagation path between the DUT socket and the measurement antenna structure is surrounded by an electromagnetic absorber in order to absorb the radiation or electromagnetic waves or their reflections used in the OTA test, which would otherwise pollute the surroundings or affect the OTA test itself, in order to improve the near-field measurement performance and the site to site isolation in multi-site testing. In a preferred embodiment the propagation path, e.g. a straight propagation path, between the receiving section and the measurement antenna structure is laterally (e.g. in a radial direction; e.g. in a plane perpendicular to the propagation path) fully surrounded (e.g. surrounded in all directions; e.g. surrounded over 360 degrees; e.g. surrounded in an enclosing manner) by the electromagnetic absorber at least over a part of a longitudinal extension of the propagation path.

[0082] For example, the propagation path is not surrounded by the electromagnetic absorber over the full longitudinal extension of the propagation path.

[0083] For example, the electromagnetic absorber surrounds a portion of the propagation path which is adjacent to the measurement antenna structure.

[0084] For example, the electromagnetic absorber does not surround a portion of the propagation path which is adjacent to the receiving section.

[0085] For example, a longitudinal extension of the electromagnetic absorber is shorter than a longitudinal extension of the propagation path.

[0086] For example, a longitudinal extension of the electromagnetic absorber is shorter than 70 percent of a longitudinal extension of the propagation path, or for example, a longitudinal extension of the electromagnetic absorber is shorter than 50 percent of a longitudinal extension of the propagation path.

[0087] For example, the longitudinal extension of the propagation path may be an extension along a propagation path, and / or wherein, for example, the longitudinal extension of the propagation path may be an extension from the DLIT position to the measurement antenna structure, e.g., to the aperture of the measurement antenna structure.

[0088] That is, the propagation path between the receiving section and the measurement antenna structure is surrounded by the electromagnetic absorber in every lateral direction in order to protect the surrounding of the OTA test area in every direction. Moreover the length of the propagation path may be longer than the length of the tubular electromagnetic absorber in order to establish a protecting gap, protecting the electromagnetic absorber from damages, in order to improve the longevity of the electromagnetic absorber.

[0089] In a preferred embodiment, the loadboard comprises an opening (e.g. a hole; e.g. an opening which is fully surrounded by load board material; e.g. an opening which is only partially surrounded by load board material, e.g. a recess adjacent to an edge of the load board). The receiving section and the measurement antenna structure are partially arranged in the opening and, consequently, for example, partially arranged within a plane of the loadboard, (e.g. such that the propagation path between the receiving section and the measurement antenna structure is partially within the plane of the loadboard).

[0090] In a preferred embodiment, the loadboard comprises an opening (e.g. a hole; e.g. an opening which is fully surrounded by load board material; e.g. an opening which is only partially surrounded by load board material, e.g. a recess adjacent to an edge of the load board). The electromagnetic absorber is at least partially arranged in the opening.

[0091] In a preferred embodiment, the electromagnetic absorber is arranged to form a propagation tunnel, surrounded by the electromagnetic absorber, between the receiving section and the measurement antenna structure, at least over a part of the propagation path between the measurement antenna structure and the receiving section.

[0092] For example, such that an axis of the propagation tunnel is tilted with respect to the plane of the load board by no more than 10 degree.

[0093] For example, such that an inside of the propagation tunnel surrounded by the electromagnetic absorber is in a plane of the loadboard.

[0094] In a preferred embodiment, the DUT socket is configured to accept an L-shaped DUT.

[0095] In a preferred embodiment, the one or more surfaces, e.g. inner surfaces, of the electromagnetic absorber facing towards the propagation path between the receiving section and the measurement antenna structure comprise, e.g. are formed by, a plurality of pyramidlike structures, e.g. pyramids or truncated pyramids or cone-like structures, e.g. cones or truncated cones (e.g. comprising, or made of, electromagnetically absorbing material.

[0096] In a preferred embodiment, a height of the pyramid-like structures or cone-like structures is within a range between 0.1 times a wavelength (e.g. a free-space wavelength] at a lowest frequency of operation [e.g. at a lowest frequency for which an over-the-air testing is to be performed] (e.g. at a lowest frequency of 15 operation of the DUT socket) and 0.4 times a wavelength (e.g. a free-space wave-length) at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed) (e.g. at a lowest frequency of operation of the DUT socket) (wherein the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket).

[0097] Alternatively, the height of the pyramid-like structures or cone-like structures is within a range between 0.2 times a wavelength (e.g. a free-space wavelength) at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed) (e.g. at a lowest frequency of operation of the DUT socket) and 0.3 times a wavelength (e.g. a free-space wavelength) at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed) (e.g. at a lowest frequency of operation of the DUT socket) (wherein the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket).

[0098] In a preferred embodiment, an area of the base of the pyramid-like structures or of the conelike structures is within a range of 0.2-0.4 times the square of the wavelength at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed) (e.g. at a lowest frequency of operation of the DUT socket) (wherein the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket).

[0099] In a preferred embodiment, in a portion in which the electromagnetic absorber surrounds the propagation path (e.g. in a direction perpendicular to a propagation path between the receiving section and the measurement antenna structure) a width of a clearance (e.g. a width of a clearance between opposite surfaces of the electromagnetic absorber; e.g. a distance between peaks of opposite pyramid-like structures or cone-like structures, e.g. a width of a clearance for a propagation of waves from the receiving section to the measurement antenna structure, or vice versa, e.g. an inner dimension between opposite structures of the electromagnetic absorber) is within a range between 0.2 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket) and 0.4 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket). For example, the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket.

[0100] Alternatively, for example, in a portion in which the electromagnetic absorber surrounds the propagation path, a width of a clearance (e.g. a width of a clearance between opposite surfaces of the electromagnetic absorber; e.g. a distance between peaks of opposite pyramid-like structures or cone-like structures) is within a range between 0.3 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket) and 0.5 times a wavelength, e.g. a free-space wavelength, at a lowest frequency of operation (e.g. at a lowest frequency for which an over-the-air testing is to be performed, e.g. at a lowest frequency of operation of the DUT socket). For example, the lowest frequency of operation may, for example, be defined by a test antenna which is part of the DUT socket.

[0101] In a preferred embodiment the test arrangement comprises a further electromagnetic absorber portion with an opening. The further electromagnetic absorber portion is arranged to at least partially cover a surface of a conductive structure comprising the measurement antenna structure or carrying the measurement antenna structure.

[0102] For example, to act as an electromagnetically absorbing intermediate layer between a volume surrounded by the electromagnetic absorber and the conductive structure comprising the antenna structure or carrying the antenna structure.

[0103] For example, an environment of the antenna structure is exempt in the further electromagnetic absorber portion, e.g. in the form of the opening. For example, the surface of the conductive structure is facing towards the DUT position.

[0104] For example, the further electromagnetic absorber portion is arranged such that the opening is located on an electromagnetic propagation path between the measurement antenna structure and the receiving section.

[0105] For example, such that the opening allows an electromagnetic propagation between the measurement antenna structure and the receiving section.

[0106] In a preferred embodiment, the test arrangement further comprises a pusher configured to push a DUT towards the receiving section (e.g. towards an angled DUT position for accepting the DUT, e.g. towards a contact structure for contacting the DUT, e.g. towards a receiving section within the DUT socket) or to push the DUT into the receiving section (e.g. into an angled DUT position for accepting the DUT, e.g. into a contact structure for contacting the DUT, e.g. into an angled receiving section within the DUT socket, e.g. by using a pushing surface of the pusher.

[0107] The pusher is at least partially surrounded, e.g. in a region of its lateral surface by an second electromagnetic absorber, e.g. an RF absorber.

[0108] Any features, functionalities and details disclosed herein with respect to the pusher and with respect to the electromagnetic absorber surrounding the pusher may optionally also apply.

[0109] In a preferred embodiment the receiving section is an angled DUT position for accepting an angled DUT (e.g. for accepting a non-planar DUT; e.g. for accepting an L-shaped DUT).

[0110] The measurement antenna structure arranged in a way that a propagation path between the DUT position, e.g. a first portion of the angled DUT position, and the measurement antenna structure is tilted with respect to a plane of a load board, e.g. a load board to which the DUT socket is attached, by no more than 45 degrees is a first measurement antenna structure. The test arrangement further comprises a second measurement antenna structure, e.g. in addition to first the measurement antenna structure mentioned before.

[0111] The first measurement antenna structure is arranged in such a way that there is a first straight propagation path between the first measurement antenna structure and a first portion of the angled DUT position or, equivalently, between the first test antenna structure and a first surface of an angled DUT when the angled DUT is inserted into the DUT socket.

[0112] The second measurement antenna structure is arranged in such a way that there is a second straight propagation path between the second measurement antenna structure and a second portion of the angled DUT position or, equivalently, between the second measurement antenna structure and a second surface of an angled DUT when the angled DUT is inserted into the DUT socket.

[0113] The propagation path between the second portion of the receiving section, e.g. a second portion of the angled DUT position, and the second measurement antenna structure extends through the pusher and is at least partially surrounded by the second electromagnetic absorber.

[0114] For example, the second measurement antenna structure is arranged in a way that a propagation path between the second portion of the receiving section, e.g. a second portion of the angled DUT position, and the second measurement antenna structure is substantially perpendicular, with a tolerance of + / -20 degree, to the propagation path between the first portion of the receiving section, e.g. the first portion of the DUT position, and the first measurement antenna structure.

[0115] The condition of at least substantial orthogonality may apply in a projection into a plane perpendicular to a plane of the load board and comprising the propagation path between the first portion of the receiving section and the first measurement antenna if the propagation path between the first portion of the DUT position and the first measurement antenna structure and the propagation path between the second portion of the DUT position and the second measurement antenna structure do not intersect.

[0116] An embodiment creates a test cell comprising a plurality of test arrangements as discussed herein, wherein, for example, the one or more electromagnetic absorbers are configured to at least partially absorb radiation propagating from a test site to another test site. In a preferred embodiment an automated test equipment comprises a test cell comprising a plurality of test arrangements, e.g. arranged at different test sites or a test arrangement.

[0117] For example, the electromagnetic absorber is configured to at least partially absorb radiation propagating from a test site to another test site.

[0118] In a preferred embodiment an automatic test equipment comprises multiple test cells with a plurality of the above mentioned test arrangements. For example, test arrangements arranged close to each other within a test cell conducting tests simultaneously on similar or same DUTs, so that, for example, the one or more electromagnetic absorbers are configured to at least partially absorb radiation propagating from a test arrangement to another test arrangement. For example, test cells of an automatic test equipment are arranged at different test sites within one or more production lines, so that, for example, the one or more electromagnetic absorbers are configured to at least partially absorb radiation propagating from a test arrangement to another test arrangement or from a test site to another test site.

[0119] OTA sockets are platform independent, that means they can be copied or used on any platforms. It has been shown, that the electromagnetic absorber described above significantly improves the performance of the OTA testing with near field sockets.

[0120] Brief of the

[0121] Embodiments according to the present application will subsequently be described taking reference to the enclosed figures, in which:

[0122] Fig. 1 shows a schematic diagram of a DUT socket structure with a pusher surrounded by an electromagnetic absorber, according to an embodiment;

[0123] Fig. 2 shows a schematic diagram of test arrangement with a pusher surrounded by an electromagnetic absorber, according to an embodiment;

[0124] Fig. 3 shows a schematic diagram of an arrangement comprising two test arrangements, both having an electromagnetic absorber, according to an embodiment; Fig. 4 shows a schematic diagram of a test arrangement without a pusher having an electromagnetic absorber, according to an embodiment;

[0125] Fig. 5 a-c) show pictures of a conventional test arrangement;

[0126] Figs 6 a-d) show a perspective view and a cross-sectional view of a simulations of a socket structure with and without an electromagnetic absorber surrounding the pusher;

[0127] Figs 7 a-d) show a cross-section view of simulations of test arrangement and their simulated magnetic fields with and without an electromagnetic absorber surrounding the pusher;

[0128] Fig. 8 shows the electromagnetic absorber according to an embodiment used in an inventive DUT socket structure or in an inventive test arrangement;

[0129] Fig.9 shows a picture a test arrangement according to an embodiment attached to an arm of a positioning structure;

[0130] Fig 10 shows a picture of an embodiment, in which the receiving section is surrounded by an electromagnetic absorber;

[0131] Fig. 11 a-d) show a comparison of test arrangements with or without electromagnetic absorber;

[0132] Fig. 12a-d) show a comparison of test arrangements comprising different socket structures: far field socket, and near-field sockets with or without an electromagnetic absorber;

[0133] Fig. 13 shows a cross-section view of an embodiment of a test arrangement;

[0134] Fig. 14a-b) shows a perspective view of a simulation of a conventional test cell of multiple DUT socket structures or test arrangements without electromagnetic absorber;

[0135] Fig 15a-b) show a perspective view of simplified models of DUT socket structures with or without electromagnetic absorber used in simulated measurements of in Figs 16, 17 ;

[0136] Fig. 16a-i) show a simulated measurement setup related to conventional test arrangements and the simulated test results thereof;

[0137] Fig. 17a-i) show a simulated measurement setup related to inventive test arrangements and the simulated test results thereof;

[0138] Fig. 18a-f) show a summary or a comparison of the simulated test results of the simulated test arrangements of the Figs. 16, 17;

[0139] Fig. 19a-d) show a test cell for conventional test arrangements without an electromagnetic absorber;

[0140] Fig. 20a-f) show a comparison of the site to site isolation or absorbance between conventional test arrangements and inventive test arrangements Fig. 21a-d) show simulations of, simulated magnetic field of, and simulated comparison measurement results of the test arrangement having an L-shaped receiving section comprising a first and a second test arrangements as shown in Fig.3.

[0141] Detailed description of the embodiments

[0142] In the following, different inventive embodiments and aspects will be described. Also, further embodiments will be defined by the enclosed claims.

[0143] It should be noted that any embodiments as defined by the claims may optionally be supplemented by any of the details, features and functionalities described herein. Also, the embodiments described herein may be used individually, and may also optionally be supplemented by any of the details, features and functionalities included in the claims.

[0144] Also, it should be noted that individual aspects described herein may be used individually or in combination. Thus, details may be added to each of said individual aspects without adding details to another one of said aspects. It should also be noted that the present disclosure describes, explicitly or implicitly, features usable in a DUT socket structure or in a test arrangement or in an automatic test equipment (ATE). Thus, any of the features described herein may be used in the context of an absorber of a DUT socket structure, in the context of an absorber of a test arrangement or in the context of an absorber of an automatic test equipment.

[0145] The present invention will be understood more fully from the detailed description given below, and from the accompanying drawings of embodiments of the present invention, which, however, should not be taken to limit the present invention to the specific embodiments described, but are for explanation and understanding only.

[0146] Electromagnetic absorbers or radio frequency (RF) absorber parts are designed as part of an overall near-field socket design using three dimensional (3D) electromagnetic (EM) simulation.

[0147] Fig. 1 shows a schematic diagram of a DUT socket structure 100, comprising a pusher 110, which is at least partially surrounded by an electromagnetic absorber 140. The DUT socket structure 100 further comprises a DUT socket 120, which comprises a receiving section 130.

[0148] The pusher 110 is configured to push a DUT 150 into or toward the receiving section 130 of the DUT socket 120. For example, the pusher 110 is configured to push the DUT 150 along a pushing direction 175 or along a direction 175 of an axis of the pusher 110. For example, the pusher 110 is configured to push the DUT 150 with its pushing surface 170 to into or toward the receiving section 130 of the DUT socket 120.

[0149] The pusher 110 of the DUT socket structure 100 is at least partially, e.g. in a region of its lateral surface, surrounded by an electromagnetic absorber 140 or by a radio frequency (RF) absorber 140.

[0150] The electromagnetic absorber 140 is configured to absorb or at least partially absorb radiations, which are propagating in a direction which is not along the pushing direction 175 or along the axis of the pusher in order to improve the near-field measurement performance and the site to site isolation in multi-site testing of the DUT socket structure 100, when an OTA test or near field OTA test is conducted on the DUT 150.

[0151] The DUT socket structure 100 may optionally further comprise an electromagnetic absorber 148 arranged on the surface of the pusher 110 opposite to the pushing surface 170, for example between the pusher 110 and a positioning structure or for example between the pusher 110 and a fixing structure or for example between the pusher 110 and a waveguide structure.

[0152] For example, the receiving section 130 of the DUT socket 120 may further comprise a contact structure 160 or an electronic contact structure 160 for contacting the DUT 150 or for establishing a connection or electronic connection with the DUT 150 when the DUT 150 is pushed into the receiving section 130.

[0153] For example the DUT socket 120 comprises one or more side walls 180, i.e. a plurality of side walls, in case of the opening of the receiving section is substantially polygonal, such as rectangular or substantially quadratic or a single, substantially circular or elliptical sidewall, in case of the opening of the receiving section is substantially circular or elliptical. For example, the side walls 180 may be positioned in a lower, fixed portion of the DUT socket, remaining attached to a load board. For example, in a first arrangement 123 of a DUT socket 120 a surface of the one or more side walls 180 facing towards the receiving section 130 is at least partially covered by an electromagnetic absorber 145. The electromagnetic absorber 145 covering the side walls 180 are surrounding the receiving section 130 in order to absorb the side radiations of the DUT 150, when the DUT 150 is placed in the receiving section 130, reducing the electromagnetic pollution in the plane or environment of the receiving section 130 and further improving the near-field measurement performance and the site to site isolation in multi-site testing.

[0154] For example, in a second arrangement 126 of a DUT socket 120 the side walls 180 decline towards the receiving section 130, in order to help a positioning structure, like a picking machine, to position the DUT 150 correctly.

[0155] For example, the pusher 110 is longer than the tubular electromagnetic absorber 140, or electromagnetic absorber 140 does not extend all the way up to the end of the full length of the pusher 110, resulting in a gap 190 or a protective gap 190 between the electromagnetic absorber 140 and the DUT socket 120 or the side walls 180 of the DUT socket 120.

[0156] Similarly, additionally or alternatively, in a first arrangement of 123 of a DUT socket 120 the side walls 180 are reaching higher than the height of the electromagnetic absorber 145, resulting in a gap 190 or a protective gap 190 between the height of the side walls 180 and the height of the electromagnetic absorber 145.

[0157] The protecting gap 190 protects the electromagnetic absorber 140, 145 from damages, in order to improve the longevity of the electromagnetic absorber 140, 145.

[0158] In other words, when an OTA test or near field OTA test is conducted on a DUT 150, the electromagnetic absorber 140 reduces the electromagnetic pollution by eliminating or at least partially absorbing radiations propagating in a direction, which is not along the pushing direction 175 or along the axis of the pusher 110, in order to improve the near-field measurement performance and the site to site isolation in multi-site testing. The electromagnetic absorber 140 is protected by a protective gap 190 from a mechanical stress.

[0159] The DUT socket structure 100 may optionally supplemented by any of the features, functionalities and details disclosed herein, both individually and taken in combination. Embodiment according to Fig. 2

[0160] Fig. 2 shows a schematic diagram of test arrangement 200 comprising a DUT socket structure 260 and a measurement antenna structure 270. The DUT socket structure 260 is similar to the DUT socket structure 100 of Fig. 1 comprises a pusher 210, which is at least partially surrounded by an electromagnetic absorber 240, and a DUT socket 220, which comprises a receiving section 230, configured to receive a DUT 250.

[0161] The pusher 210 is now arranged between the measurement antenna structure 270 and the receiving section 230, so that a propagation path 280 can be established through the pusher 210 between the measurement antenna structure 270 and the receiving section 230 or the test antenna of the DUT 250, if the DUT 250 is pushed into the receiving section 230.

[0162] The surface of the electromagnetic absorber 240, but optionally also of the electromagnetic absorber 140 of Fig. 1 , facing towards the pusher comprises a plurality of pyramid-like structures 246 or cone-like structures 243. The cone- or a pyramid-like shapes improve the absorbance by reflecting the radiation diffusely and extending the path of the radiation. The height of the pyramids / truncated pyramids or cones / truncated cones are, for example, between 0.1 -0.4 times a wavelength at a lowest frequency of operation or between 0.2-0.3 times a wavelength at a lowest frequency of operation. The area of a base of the pyramids / truncated pyramids or cones / truncated cones is between 0.2-0.4 times the square of wavelength at a lowest frequency of operation.

[0163] The pusher 210 may optionally comprise a widening 215 at a longitudinal portion adjacent to the measurement antenna structure 270. The surface substantially perpendicular to the propagation path of the widening 215 may be covered by an electromagnetic absorber portion 293. For example, the electromagnetic absorber portion 293 may extend in a radial direction from the surface of the pusher 210 to the outer surface of the electromagnetic absorber 240.

[0164] For example, the test arrangement may comprise a further electromagnetic absorber portion 296 with an opening 299. The further electromagnetic absorber portion 296 is arranged between the conductive structure 275, comprising or carrying the measurement antenna structure 270, and a portion of a surface of the pusher 210, such that the opening 299 is located on the electromagnetic propagation path 280 between the measurement antenna structure 270 and the receiving section 230. The further electromagnetic absorber portion is arranged to at least partially cover the surface of the conductive structure 275 facing towards the receiving section 230.

[0165] A further electromagnetic absorber portion 296 with an opening 299 arranged between the conductive structure 275 and the pusher 210 eliminates or at least reduces the reflections of the radiation on the surface of the conductive structure 275 comprising or carrying the antenna structure 270, while not hindering the OTA test measurement by absorbing the measurement signal transmitted along the propagation path 280 between the measurement antenna structure 270 and the receiving section 230, or the test antenna of the DUT 250, through the opening 299 of the further electromagnetic absorber portion 296 and through the pusher 210.

[0166] When an OTA test or near field OTA test is conducted on a DUT 250, the electromagnetic absorber 240, having a surface with pyramid-like structures 246 and / or cone-like structures 243, reduces the electromagnetic pollution by eliminating or at least partially absorbing radiations propagating in a direction different from or not following the propagation path 280, in order to improve the near-field measurement performance and the site to site isolation in multi-site testing. For example, with the help of further electromagnetic absorber portions 293, 296 the near-field measurement performance and the site to site isolation in multi-site testing is further improved, while the near field OTA test is not affected.

[0167] The DUT socket structure 200 may optionally supplemented by any of the features, functionalities and details disclosed herein, both individually and taken in combination.

[0168] Embgdiment according to Fig. 3

[0169] Fig. 3 shows a schematic diagram of a test arrangement 300 comprising a test arrangement 360 and a test arrangement 390.

[0170] The test arrangement 360, similar to the test arrangement 200 of Fig. 2, comprises measurement antenna structure 370 a DUT with a socket structure, similar to the DUT socket structure 100 of Fig. 1 , comprising a pusher 310, which is at least partially surrounded by an electromagnetic absorber 340, and a DUT socket 320, comprising a receiving section 330. The test arrangement 390 comprises a measurement antenna structure 375, an electromagnetic absorber 345, and also the DUT socket 320 with the receiving section 330.

[0171] Unlike in the previous embodiments, the DUT 350 of the present embodiment is a non- planar DUT, which has a bent shape or angled shape. For example, in Fig. 3 an L-shaped DUT 350 is shown.

[0172] Accordingly, the DUT socket 320 is also non-planar, having a bent or angled shape, such as an L shape. For example, a loadboard 325 or a test fixture 325 holding the DUT socket 320 comprises a hole in which the non-planar receiving section 330 of the non-planar DUT socket 320 is configured to receive the non-planar DUT 350.

[0173] The non-planar DUT 350 may comprise more than one test antennas or test antenna structures, which can be tested by different test arrangements, such as the test arrangement 360 and the test arrangement 390, by transmitting or receiving test signals along a propagation path 380 or 385 between the measurement antenna structures 370 and / or 375 of the test arrangement 360 and / or 390 and the receiving section 330 or the more than one test antennas of the DUT 350. Test can be conducted one after each other or also simultaneously.

[0174] As the DUT 350 is pushed into the receiving section 330 by the pusher 310 of the test arrangement 360, there is no need for a pusher in the test arrangement 390. The propagation path 385 between the receiving section 330, or the test antenna of the DUT 350, is surrounded by an electromagnetic absorber 345 or a tubular electromagnetic absorber 345, in order to absorb the radiation, electromagnetic waves, test signals or their reflections used in the OTA test or near field OTA test, which would otherwise pollute the surroundings or affect any of the OTA test conducted in the test arrangement 360 or 390. Thus, improving the near-field measurement performance and the site to site isolation in multi-site testing.

[0175] With the embodiment of Fig. 3 the more than one test antennas of the non-planar DUTs 350, like L-shaped DUTs, could be tested simultaneously or one after each other, such that the electromagnetic absorbing materials 340 and 345 surrounding the propagation paths 280 and 285 absorb all or partially the radiation propagating in a direction different or not along the propagation path 280 and 285.

[0176] The test arrangement 390 is further described in Fig. 4. Em bod i me n t a cco r d i n q to Fie; 4

[0177] Fig. 4 shows a schematic diagram of a test arrangement 400, comprising a loadboard 425 having a hole to hold a non-planar receiving section 430 of a DUT socket 420. The test arrangement further comprises a measurement antenna structure 470 and a propagation path 480 between the receiving section 430 or the test antenna of the DUT 450. The propagation path 480 can be substantially parallel to the loadboard 425 or at least not tilted more than 45 degrees or at least not tilted more than 10 degrees from the plane of the loadboard 425.

[0178] The propagation path 480 is surrounded by an electromagnetic absorber 440 or a tubular electromagnetic absorber 440. The test arrangement 400 can be used in the test arrangement 390 of Fig 3, but it can be also used as a standalone test arrangement as well, for example when the position of the DUT 450 is fixed within the non-planar receiving section 430 of a non-planar DUT socket 420.

[0179] For example, the surface or the inner surface of the tubular electromagnetic absorber 440 facing towards the propagation path 480 may comprise pyramid-like or cone-like structures, as described above.

[0180] For example, the electromagnetic absorber 440 is forming an electromagnetic absorber tube 440 or electromagnetic absorber tunnel 440. For example, the propagation path 480 and / or the tubular electromagnetic absorber 440 is partially located within the plane of the loadboard 425. That is, the propagation path 480 between the receiving section 430 and the measurement antenna structure 470 is surrounded by the electromagnetic absorber 440 in every lateral direction in order to protect the surrounding of the OTA test area in every direction.

[0181] For example, a longitudinal extension of the electromagnetic absorber tube 440 is shorter than a longitudinal extension of the propagation path 480, such as shorter than 70 percent of a longitudinal extension of the propagation path 480, or shorter than 50 percent of a longitudinal extension of the propagation path 480. For example, in a portion in which the electromagnetic absorber 440 surrounds the propagation path 480, a width of a clearance is within a range between 0.2-0.4 times or 0.3-0.5 times a wavelength, or a free-space wavelength at a lowest frequency for which an OTA testing is to be performed. The lowest frequency of operation may, for example, be defined by the test antenna of the DUT 450. For example, the width of a clearance is an inner dimension between opposite structures of the electromagnetic absorber 440.

[0182] For example the test arrangement comprises 400 a further electromagnetic absorber portion 490 with an opening 495. The further electromagnetic absorber portion 490 is arranged such that the opening 495 is located on an electromagnetic propagation path 480 between the measurement antenna structure 470 and the receiving section 430, to at least partially cover a surface of a conductive structure 475 comprising or carrying the measurement antenna structure 470. The surface of the conductive structure 475 is facing towards the receiving section 430.

[0183] Conventional test arrangement according to Fig, 5

[0184] Fig. 5 a)-c) shows pictures of a conventional test arrangement 500.

[0185] Fig. 5a shows pictures with parts of the conventional test arrangement 500. The conventional test arrangement 500 comprises a lower part and an upper part. The lower part is attached to loadboard 525 and comprises a blindmating interconnect 530 of a waveguide and a DUT socket 520 having an antenna-in-package DUT (DUT-AiP) 550 within.

[0186] The upper part is disassembled, in the sense that the pusher 510 is separate from the conductive structure 575, which comprises or carries the measurement antenna structure 570.

[0187] Fig. 5b shows a picture in which the upper part of the conventional test arrangement 500 is assembled, i.e. the pusher is 510 is attached to the conductive structure 575.

[0188] Fig. 5c shows a picture in which the upper part of the conventional test arrangement 500 is attached or secured to the lower part of the conventional test arrangement 500.

[0189] 3U simulations according to Pig. 6 Figs 6 a-d) show a perspective view and a cross-section view of different versions of a DUT socket structure used for simulations of DUT socket structures with and without an electromagnetic absorber surrounding the pusher.

[0190] Fig 6a) shows a perspective view of a DUT socket structure for a simulation of a conventional DUT socket structure 610, similar to the conventional DUT socket structure 500 shown in the pictures of Fig. 5.

[0191] Fig 6b) shows a cross-section view of the conventional DUT socket structure 610. The arrows 630 represent multi-path reflections from the socket components, negatively impacting the measurement accuracy.

[0192] Fig. 6c) shows a perspective view of a DUT socket structure for a simulation of an inventive near-field OTA DUT socket structure 620, similar to the inventive socket 100 structure of Fig. 1 , comprising an electromagnetic absorber 650 or RF absorber 650 added to the near- field OTA DUT socket structure, around or surrounding the pusher. In some embodiments it may optionally added to the side walls of the DUT socket as well.

[0193] Fig 6d) shows a cross-section view of the inventive DUT socket structure 620. The cross- sectional view further shows the inner surface of the electromagnetic absorber, which comprises a plurality of pyramid- or cone-like structures 640. The pyramid- or cone-like structures or the pyramid design is used to further disperse the radiation or the reflections thereof in or within the electromagnetic absorber.

[0194] Simulations according to Fig. 7

[0195] Figs 7 a-d) show a cross-section view of simulated structures used in simulations of test arrangements and their simulated magnetic fields with and without an electromagnetic absorber surrounding the pusher.

[0196] Fig 7a) shows a cross-section view of the conventional test arrangement 710 without an electromagnetic absorber, similar to the conventional test arrangement 500 shown in the pictures of Fig. 5.

[0197] Fig 7b) shows a cross-section view of a simulated electromagnetic field of the conventional test arrangement 710 without an electromagnetic absorber. Fig 7c) shows a cross-section view of the inventive test arrangement 720 with an electromagnetic absorber 730.

[0198] Fig 7d) shows a cross-section view of a simulated electromagnetic field of the inventive test arrangement 720 with an electromagnetic absorber 730.

[0199] When comparing the cross-section view of a simulated electromagnetic fields of test arrangements with or without electromagnetic absorber 730, it becomes clear that the electromagnetic absorber 730 encloses the electromagnetic radiation and eliminates or substantially reduces the electromagnetic pollution.

[0200] Electroi nagnetic absorber accotdinq to Fig 8

[0201] Fig. 8 shows a picture of the electromagnetic absorber 810, which may be used in the inventive DUT socket structure 100 of Fig. 1 , or in any of the inventive test arrangements of Figs. 2-4. The electromagnetic absorber may, for example, be produced by 3d printing technology or by molding technology either as a one piece unit 810 or as parts 820 which could be assembled into a single electromagnetic absorber 810. In the example shown in the picture the RF absorber module is 3D printed using a special RF absorber material into four parts, which are glued together afterwards. 3D printing or 3D printing techniques allows an easy way of creating pyramid-like shapes 830 or cone-like shapes 830, which would not be easy to do or produce by using or gluing together individual sheets o RF absorbing material.

[0202] Po sit ip D i HQ structure according to Fig, 9

[0203] Fig.9 shows a picture of a DUT socket structure or a picture of a test arrangement 920 according to an embodiment comprising a positioning structure 910 and attached to an arm 910 of a handler. The arm of the handler is configured to lift up the pusher surrounded with the electromagnetic absorber 930, while another arm or another positioning structure replaces the DUT within the receiving section, which non-visible in the picture. The rods 940 are, for example, substantially parallel to the pusher or to the axis of the pusher to support the correct positioning. Fig 10 shows a picture of an embodiment, in which the receiving section 1030 of the DUT socket 1020 is surrounded by an electromagnetic absorber 1045, similar to the first arrangement 123 of the DUT socket 120 in Fig. 1. It is also visible in the picture, that the pusher 1010 of the test arrangement or the DUT socket structure is surrounded by an electromagnetic absorber 1040.

[0204] Comparison a cco rd i n q to Fig . 11

[0205] Fig. 11a-d) show a comparison of test arrangements with or without electromagnetic absorber.

[0206] Fig. 11 a) shows pictures of a conventional test arrangement without electromagnetic absorber used in the comparison.

[0207] Fig. 11 b) shows pictures of an inventive test arrangement with the electromagnetic absorber used in the comparison.

[0208] Fig. 11 c) shows a plot of the measured transmit power across frequency of the DUT antenna array in constructive beam forming mode and of each individual antenna elements without electromagnetic absorber, as shown in the pictures of Fig 11a).

[0209] Fig. 11 d) shows a plot of the measured transmit power across frequency of the DUT antenna array in constructive beam forming mode and of each individual antenna elements with electromagnetic absorber, as shown in the pictures of Fig 11 b).

[0210] When comparing the diagrams with the test result of Fig 11 c) and d) it is clearly shown that the addition of the RF absorber reduces the measured power difference between the individual antenna elements in a near-field measurement, providing a better correlation with a reference far-field measurement. The addition of the RF absorber improves the near-field measurement results compared with conventional OTA socket structures or conventional test arrangements with no RF absorbers.

[0211] Comparison according to Fig. 12 Fig. 12a-d) show a comparison of test arrangements comprising different sockets or socket structures: far field socket, and near-field sockets with or without an electromagnetic absorber.

[0212] Fig 12a) shows a test arrangements comprising a far-field socket structure used in the comparison.

[0213] Fig 12b) shows a test arrangements comprising a near-field socket structure having an electromagnetic absorber surrounding the pusher and the receiving section used in the comparison.

[0214] Fig 12c) shows a test arrangements comprising a near-field socket structure not having any electromagnetic absorber, used in the comparison.

[0215] Fig. 12d) shows a diagram with the result of the comparison. The diagram shows, that the results of the measured transmitted power from the DUT of the near field socket structures with electromagnetic absorber shows a more monotonic behavior than without the electromagnetic absorber. This improved monotonicity significantly helps to creating a calibration table for correlating with far-field measurements.

[0216] Embodiment according to Fig. 13

[0217] Fig. 13 shows an embodiment of a test arrangement 1300, similar to the test arrangement of Fig 2.

[0218] The test arrangement 1300 comprises a pusher 1310 with a widening 1320. The surface of the widening facing towards the receiving section is covered by an electromagnetic absorber portion 1330.

[0219] Moreover, Fig. 13 also shows dimensional values related to the electromagnetic absorber 1340 of the exemplary embodiment. Accordingly, the tubular electromagnetic absorber 1340 is shorter than the length of the pusher, such that when the pusher pushes the DUT into or towards the DUT socket 1350, the distance between the tubular electromagnetic absorber 1340 and the DUT socket 1350 is, for example, 2mm. This gap helps to avoid mechanical wear of the absorber, while still providing for a good electromagnetic characteristic. Further, Fig. 13 shows that the inner surface of the tubular electromagnetic absorber 1340 or the surface facing towards the pusher 1310 comprises truncated pyramids 1360 with a height of 4mm. The distance between the tip or truncated tip of the pyramid 1360 and the pusher 1310 is 7.1 mm. Fig. 13 shows also that the total width of the electromagnetic absorber 1340, that is, the width of the tubular part in addition to the height of the truncated pyramids, is 7 mm.

[0220] The dimensions of the electromagnetic absorber is mainly determined by the mechanical requirements. The requirements are related to, for example, the dimensions of the antenna in package (AiP) module, the pitch between the neighboring sites and the mechanical requirements of the handler or the positioning structure. However, it has been found that the dimensioning disclosed here also results in good electromagnetic characteristics.

[0221] A large distance between the absorber structure and the DUT is preferred with pyramids having a height high enough to support the lowest frequency being tested. In some cases, compromise is need to be made in the small geometries of the ATE OTA sockets for the allowed mechanical space used. For example, the dimension of the DUT in the example shown is 17mmx17mm. Three dimensional (3D) electromagnetic (EM) simulations are also used.

[0222] The dimensional values follows the wavelength-dependent directives discussed above, for example, by the embodiment according to Fig. 2.

[0223] The absorber should also not impact the workings of the pusher by for example hitting the socket and stopping the pusher doing its job. In the example shown a 2 mm gap is used to guarantee that.

[0224] S i m u la tio n a cco rd i ng to Fig . 4

[0225] Fig. 14a-b) show a perspective view of an DUT socket structure for simulation of a conventional test cell of multiple DUT socket structures or test arrangements without electromagnetic absorber. The test cell is an example of a multi-site change kit without isolation or electromagnetic absorber. Fig 14a) shows that the test cell comprises eight DUT socket structures 1430 or test arrangements 1430 are positioned close to each other on a loadboard 1 20.

[0226] Fig 14b) shows that the eight DUT test arrangements 1430 are positioned at least close enough to negatively affect each other’s test results. The thunderbolt-signs 1410 represents a site to site cross talk between the test arrangements, which is negatively affecting the results of the tests or measurement conducted simultaneously within test arrangements 1430 close to each other.

[0227] The inventive DUT socket structures or test arrangements eliminates or at least substantially reduces the illustrated site to site cross talk effect and improves the near-field measurement performance.

[0228] Simulation according to Fig. l b

[0229] Fig 15 a-b) show a perspective view of simplified models of DUT socket structures 1510,1520 with or without an electromagnetic absorber 1530, which are used in the simulated comparison in Figs 16 and 17.

[0230] Fig 15 a) show a perspective view of a simplified model of a DUT socket structure 1510 without an electromagnetic absorber 1530, which is used in the simulated test related to Fig. 16.

[0231] Fig 15 b) show a perspective view of a simplified model of a DUT socket structure 1520 with an electromagnetic absorber 1530, which is used in the simulated test related to Fig. 17.

[0232] Simulated measurement according to Fig. 16

[0233] Fig. 16a-i) shows a simulated measurement setup related to conventional test arrangements and the results thereof.

[0234] Fig. 16a) shows a perspective view of a simulated test cell 1650 on a loadboard 1630 with 8 conventional test arrangements 1610 without any electromagnetic absorber. Fig. 16b) shows a perspective view of a simulated DUT 1620 used for the simulated measurements in the test arrangements 1610.

[0235] Fig. 16c) shows a perspective view of a simulated arrangement 1645 of two conventional test arrangements 1610 which are arranged in a similar way as two neighboring conventional test arrangements 1610 within the test cell 1650. The simulated arrangement 1645 further comprises a boundary 1640. At the top boundary, which simulates the conductive structure comprising or carrying the measurement antenna structure 1660, the electric field E is defined to be E=0. At the bottom boundary, which simulates the loadboard 1630 of the arrangement, the electric field E is defined to be E=0.

[0236] Fig. 16d) shows a perspective bottom view of the simulated arrangement 1645 of Fig 16c) to show the DUTs 1620 and the measurement antenna structures 1660 of the test arrangement 1610. In order to see the measurement antenna structures 1660, the pushers are not shown.

[0237] Fig. 16e) shows a perspective view of the simulated arrangement 1645 of Fig 16c) with the pushers as well. Here, only the test arrangement 1670 is conducting measurements, while the test arrangement 1675 remains idle. Only one single antenna of DUT 1620 in the test arrangement 1670 close to the center of the arrangement 1645 is transmitting a radiation.

[0238] In the measurement of the absorbance or of the isolation only a single antenna element is used, since the radiation beam is broader than in beamforming mode. The power of the adjacent idle site or measurement antenna structure of the idle test arrangement 1675 is then measured.

[0239] Fig 16f) shows a cross-section view of a simulated electromagnetic field of the simulated test conducted in the arrangement 1645 of Fig 16e). Fig. 16f) shows that the electromagnetic radiation of the single antenna of the DUT 1620 within the test arrangement 1670 affects the potential tests or measurements conducted within the idle test arrangement 1675 in the close environment of the test arrangement 1670.

[0240] Fig 16g-i) show diagrams - having frequency values in GHz on the abscissa and radiation power values in dB on the ordinate - with the results of the simulated test shown in Figs 16e-f). The transmitting ports of the DUT are denoted as 1 and 2 for each polarization, the receiving ports of the measurement antenna structure of the test arrangement 1670 is denoted as 9 and 10, while receiving ports of the measurement antenna structure of the idle test arrangement 1675 is denoted as 11 and 12 for each polarization.

[0241] Fig 16g) shows a diagram with the results of the simulations, in which port 1 or the antenna horizontal polarization denoted as 1 of the DUT is transmitting a radiation, which is received at the measurement antennas denoted as 9 and 10 of the test arrangement 1670 and at the measurement antennas denoted as 11 and 12 of the idle test arrangement 1675.

[0242] Fig 16h) shows a diagram with the results of the simulations, in which port 2 or the antenna vertical polarization denoted as 2 of the DUT is transmitting a radiation, which is received at the measurement antennas denoted as 9 and 10 of the test arrangement 1670 and at the measurement antennas denoted as 11 and 12 of the idle test arrangement 1675.

[0243] Fig 16i) shows a diagram with the results of the simulations, in which the measurement antennas denoted as 9 and 10 of the test arrangement 1670 are transmitting the radiation which is received by the measurement antennas denoted as 11 and 12 of the idle test arrangement 1675. In other words, Fig. 16i shows the isolation between the measurement antennas of test arrangement 1670 and 1675 (e.g. (11 ,9), (12,9), (11 ,10), (12,10)).

[0244] Looking at the simulated test results, it is clear that test or measurements conducted within the test arrangement 1670 affects the measurements or tests conducted within the adjacent idle test arrangement 1675.

[0245] Simulated measure m e n t a c cording to Fi q.

[0246] Fig. 17a) shows a perspective view of a simulated test cell 1750 on a loadboard 1730 with 8 inventive test arrangements 1710 with an electromagnetic absorber 1780.

[0247] Fig. 17b) shows a perspective view of a simulated DUT 1720 used for the simulated measurements in the inventive test arrangements 1710.

[0248] Fig. 17c) shows a perspective view of a simulated arrangement 1745 of two inventive test arrangements 1710 with an electromagnetic absorber 1780 which are arranged in a similar way as two neighboring conventional test arrangements 1710 within the test cell 1750. The simulated arrangement 1745 further comprises a boundary 1740. At the top boundary, which simulates the conductive structure comprising or carrying the measurement antenna structure 1760, the electric field E is defined to be E=0. At the bottom boundary, which simulates the loadboard 1730 of the arrangement, the electric field E is also defined to be E=0.

[0249] Fig. 17d) shows a cross section view of the simulated arrangement 1745 of Fig 17c) showing the measurement antenna structures 1760, the electromagnetic absorber 1785 and the pusher 1785 of the test arrangement 1710. It is also visible that the surface of the electromagnetic absorber 1780 comprise multitude of pyramid-like structures 1783.

[0250] Fig. 17e) shows a perspective view of the simulated arrangement 1745 of Fig 17c). Here, only the test arrangement 1770 is conducting measurements, while the test arrangement 1775 remains idle. Only one single antenna of DUT 1720 in the test arrangement 1770 close to the center of the arrangement 1745 is transmitting a radiation.

[0251] In the measurement of the absorbance or of the isolation only a single antenna element is used, since the radiation beam is broader than in beamforming mode. The power of the adjacent idle site or measurement antenna structure of the idle test arrangement 1775 is then measured.

[0252] Fig 17f) shows a cross-section view of a simulated electromagnetic field of the simulated test conducted in the arrangement 1745 of Fig 17e). Fig. 17f) shows that the electromagnetic absorber 1780 eliminates or substantially reduces the radiation received by the measurement antenna within the idle test arrangement 1775. That is, the electromagnetic radiation of the single antenna of the DUT 1720 within the test arrangement 1770 does not affect or affects minimally the potential tests or measurements conducted within the idle test arrangement 1775 in the close environment of the test arrangement 1770.

[0253] Fig 17g-i) show diagrams - having frequency values in GHz on the abscissa and radiation power values in dB on the ordinate - with the results of the simulated test shown in Figs 17e-f). The transmitting ports of the DUT are denoted as 1 and 2 for each polarization, the receiving ports of the measurement antenna structure of the test arrangement 1770 is denoted as 9 and 10, while receiving ports of the measurement antenna structure of the idle test arrangement 1775 is denoted as 11 and 12 for each polarization. Fig 17g) shows a diagram with the results of the simulations, in which port 1 or the antenna horizontal polarization denoted as 1 of the DUT is transmitting a radiation, which is received at the measurement antennas denoted as 9 and 10 of the test arrangement 1770 and at the measurement antennas denoted as 11 and 12 of the idle test arrangement 1775.

[0254] Fig 17h) shows a diagram with the results of the simulations, in which port 2 or the antenna vertical polarization denoted as 2 of the DUT is transmitting a radiation, which is received at the measurement antennas denoted as 9 and 10 of the test arrangement 1770 and at the measurement antennas denoted as 11 and 12 of the idle test arrangement 1775.

[0255] Fig 17i) shows a diagram with the results of the simulations, in which the measurement antenna denoted as 9 and 10 of the test arrangement 1770 is transmitting the radiation which is received by the measurement antenna denoted as 11 and 12 of the idle test arrangement 1775.

[0256] Comparing the simulated test results of Figs. 17g-i) to the simulated test results of Figs. 16g-i) it is clear that the results of the simulated measured transmitted power in the test arrangement 1770 of Figs. 17g-i) are less volatile, showing that the electromagnetic absorber 1780 does improve the measurement performance.

[0257] Also, the radiation power of the radiation received by the measurement antenna of the adjacent idle test arrangement has in average a lower value in Figs. 17g-i) than in Figs. 16g- i), showing that the electromagnetic absorber 1780 does improve site to site isolation in a multi-site testing environment. These differences become more obvious from looking at the diagram of Fig. 18f).

[0258] Summary ol the simulated measuromeints according Io I jq. 'Is

[0259] Fig. 18 a-f) shows a summary or a comparison of the simulated test results of the simulated test arrangements of the Figs. 16, 17.

[0260] Fig. 18a) shows a top down view of a simulated arrangement 1810 comprising two neighboring DUT sockets 1820 with DUTs. It is highlighted, that the pitch between the neighboring sites or the distance between the DUTs or the middle-point of the DUTs used in the neighboring simulated tests arrangement is 60 mm. Fig 18b) shows a cross section view of the simulated arrangement 1810 showing the measurement antenna structures 1830, the electromagnetic absorber 1840 and the pusher 1850 of the test arrangement 1810.

[0261] Fig. 18c) shows a cross section view of the simulated arrangement 1810 showing the measurement antenna structures 1830, the electromagnetic absorber 1840 and the pusher 1850 of the test arrangement 1810, as shown in Fig. 17d). It is also visible that the surface of the electromagnetic absorber 1840 comprise multitude of pyramid-like structures.

[0262] Fig 18d) shows a cross-section view of a simulated electromagnetic field of the simulated test conducted in the simulated test arrangement 1810. Fig. 18d) shows that the electromagnetic radiation of the single antenna of the DUT within a first test arrangement of the test arrangement of 1810 affects the potential tests or measurements conducted within the idle second test arrangement within the test arrangement 1810 in the close environment of the first test arrangement.

[0263] Fig 18e) shows a cross-section view of a simulated electromagnetic field of the simulated test conducted in the simulated test arrangement 1810. Fig. 18e) shows that the electromagnetic absorber 1810 surrounding the pusher eliminates or substantially reduces the radiation received by the measurement antenna within the idle second test arrangement. That is, the electromagnetic radiation of the single antenna of the DUT within the first test arrangement does not affect or affects minimally the potential tests or measurements conducted within the idle second test arrangement in the close environment of the first test arrangement.

[0264] Fig. 18f) shows a diagram - having frequency values in GHz on the abscissa and radiation power values in dB on the ordinate - which summarizes of the results of the simulated test results of the Figs. 16, 17. The two antennas or ports of the DUT and of the measurement antenna structures have different polarization, so the diagrams of the Figures 16g-i) and 17g-i) can be merged into one single diagram, in which the number of curves are reduced or corresponding curves are averaged based on the polarization direction of the transmitting and receiving antennas. Accordingly four different types are shown with or without electromagnetic absorber: co-polarized, cross-polarized, adjacent co-polarized and adjacent cross-polarized. Comparing the simulated test result curves of Figs. 18f) it is clear that the results of the simulated test within a test arrangement in which the pusher is surrounded by an electromagnetic absorber are less volatile, showing that the inventive test arrangement with the electromagnetic absorber has an improved measurement performance.

[0265] Also, the radiation power of the radiation received by the measurement antenna of the adjacent idle test arrangement is in average lower if the test arrangement comprises an electromagnetic absorber than if it does not comprise it. This shows that the electromagnetic absorber does improve site to site isolation in a multi-site testing environment.

[0266] Test arrangement according to Fig. 19

[0267] Fig. 19a-i) shows a test cell for conventional test arrangements without an electromagnetic absorber.

[0268] Fig. 19a) shows a top down photo of a test cell 1950 on a loadboard 1930 with eight OUT sockets 1910.

[0269] Fig. 19b) shows a perspective photo of the test cell 1950 with eight OUT sockets 1910, which were simulated in the simulated test or measurements related to conventional and inventive test arrangements above in the Figs. 16, 17 and 18. The pitch or multi-site pitch, i.e. a distance between neighboring DUT sockets, in an X direction is 60 mm, while in Y direction is 63.5 mm.

[0270] Fig 19c) shows a photo of the test cell 1950 with eight DUT sockets 1910 and the corresponding upper part of a conventional test arrangement attached to a positioning structure 1960.

[0271] Fig 19d) shows a close-up photo of two conventional socket structures 1970 of the test cell 1950 in a closed position.

[0272] Comparison according to Fig. 20

[0273] Fig. 20a-f) shows a comparison of the site to site isolation or absorbance between conventional test arrangements and inventive test arrangements. Figs. 20a), b) show photo of a two conventional test arrangements 2010 without an electromagnetic absorber which are arranged in a similar way as two neighboring conventional test arrangements 2010 within the test cell 1950 of Fig. 19. In the comparison test, one of the conventional test arrangements is active, while the other one remains idle.

[0274] Figs. 20c) shows a photo of an conventional test arrangements 2010 with an electromagnetic absorber 2020 which is intended to surround the pusher 2030 of the conventional test arrangement, thereby forming an inventive test arrangement 2040. In the comparison test, one of the inventive test arrangements is active, while the other one remains idle.

[0275] Figs. 20d),e) show photo of a two inventive test arrangements 2040 with an electromagnetic absorber 2020 surrounding the pusher 2030, which are arranged in a similar way as two neighboring test arrangements within the test cell 1950 of Fig. 19.

[0276] Fig 20f) shows a diagram - having frequency values in GHz on the abscissa and radiation power values in dB on the ordinate - with the results of a comparison test or measurement comparing radiation powers measured in active and in idle conventional test arrangements and in active and in idle inventive test arrangements.

[0277] The diagram shows curves representing measurements of radiation powers transmitted and received by antennas with the same polarization, i.e. co-polarized radiation, within the active conventional and inventive test arrangements.

[0278] The diagram also shows curves representing measurements of radiation powers transmitted by an antenna of an active test arrangement and received or measured by antenna within an adjacent idle test arrangement. The transmitting and receiving antennas having the same polarization. The shown curves represent measurements of conventional test arrangements and measurements of inventive test arrangements as well.

[0279] The conducted comparison has shown similar results as the simulated comparison shown in Figs. 16-18.

[0280] Comparing the test results of the conventional and the inventive test arrangement, i.e. the curves of Figs. 20f), it is clear that the curves related to the test arrangement in which the pusher is surrounded by an electromagnetic absorber are less volatile, showing that the inventive test arrangement with the electromagnetic absorber has an improved measurement performance.

[0281] Also, the radiation power of the radiation received by the measurement antenna of the adjacent idle test arrangement is in average lower if the test arrangement comprises an electromagnetic absorber than if it does not comprise it. This shows that the electromagnetic absorber does improve site to site isolation in a multi-site testing environment. This is a significant improvement in isolation and also an improvement in the co-polarization performance.

[0282] Simulation of an embodiment according to Fig 21

[0283] Figs 21 a-d) show simulations of, simulated magnetic field of, and simulated comparison measurement results of the test arrangement having an L-shaped receiving section comprising a first and a second test arrangements as shown in Fig.3

[0284] Fig 21a) shows a perspective view of an inventive test arrangement 2100 with an electromagnetic absorber 2120 surrounding the pusher 2110 related to the first measurement arrangement and with a tubular electromagnetic absorber 2130 surrounding a propagation path 2140 related to the second test arrangement of the inventive test arrangement 2100.

[0285] Fig 21 b) shows a perspective view of an inventive test arrangement 2100 with an electromagnetic absorber 2120 surrounding the pusher 2110 related to the first measurement arrangement and with a tubular electromagnetic absorber 2130 surrounding a propagation path 2140 related to the second test arrangement of the inventive test arrangement 2100.

[0286] Fig 21c) shows a cross-section view of a simulated electromagnetic field of a conventional test arrangement 2100 without an electromagnetic absorber 2120 surrounding the pusher 2110 related to the first measurement arrangement and without a tubular electromagnetic absorber 2130 surrounding the propagation path 2140 related to the second test arrangement of the inventive test arrangement 2100, during a test conducted in the first test arrangement of the inventive test arrangement 2100.

[0287] Fig 21 d) shows a cross-section view of a simulated electromagnetic field of the inventive test arrangement 2100 with an electromagnetic absorber 2120 surrounding the pusher 2110 related to the first measurement arrangement and with a tubular electromagnetic absorber 2130 surrounding the propagation path 2140 related to the second test arrangement of the inventive test arrangement 2100, during a test conducted in the first test arrangement of the inventive test arrangement 2100.

[0288] When comparing the cross-section view of a simulated electromagnetic fields of test arrangements with or without electromagnetic absorbers 2120, 2130, it becomes clear that the electromagnetic absorbers 2120, 2130 eliminate or substantially reduce the electromagnetic pollution in the environment of the arrangement, improve the near-field measurement performance and the site to site isolation in a multi-site testing.

[0289] Fig 21 e) shows a simulated non-planar, or L-shaped DUT 2150, which is used in the simulated comparison test. The DUT comprises multiple antennas 2160, from which the antenna on the edge 2153 is tested. When pushed into the test arrangement with an L-shaped receiver section by the pusher 2110, the antenna is facing toward the pusher 2110, so that the antenna can be tested by the first test arrangement.

[0290] Fig 21f) shows a diagram - having frequency values in GHz on the abscissa and radiation power values in dB on the ordinate - with the results of a simulated comparison test, in which the antenna of DUT 2153 transmits a radiation, which is received by the co-polarized and by the cross-polarized antenna of the measurement antenna structure of both the first and the second test arrangement of the test arrangement 2100. The diagram comprises both curves representing measurements conducted within a conventional test arrangement without electromagnetic absorbers and curves representing measurements conducted within an inventive test arrangement with electromagnetic absorbers 2120, 2130.

[0291] Fig 21g) shows a simulated non-planar, or L-shaped DUT 2150, which is used in the simulated comparison test. The DUT comprises multiple antennas 2160, from which the antenna on the middle 2156 is tested. When pushed into the test arrangement with an L-shaped receiver section by the pusher 2110, the antenna is facing toward the pusher 2110, so that the antenna can be tested by the first test arrangement.

[0292] Fig 21 h) shows a diagram - having frequency values in GHz on the abscissa and radiation power values in dB on the ordinate - with the results of a simulated comparison test, in which the antenna of DUT 2156 transmits a radiation, which is received by the co-polarized and by the cross-polarized antenna of the measurement antenna structure of both the first and the second test arrangement of the test arrangement 2100. The diagram comprises both curves representing measurements conducted within a conventional test arrangement without electromagnetic absorbers and curves representing measurements conducted within an inventive test arrangement with electromagnetic absorbers 2120, 2130. Looking at the diagrams of Figs. 21 f) and h) it is clear that the radiation power of the radiation received by the measurement antenna of the adjacent idle test arrangement is in average lower if the test arrangement comprises an electromagnetic absorber than if it does not comprise it. This shows that the electromagnetic absorber does improve site to site isolation in a multi-site testing environment.

Claims

Claims1. A device under test, DUT, socket structure (100, 260, 620, 1510, 1520) comprising a pusher (110, 210, 310, 510, 1310, 1785, 1850, 2030, 2110) and a DUT socket (120,220, 320, 420, 520, 1020, 1350, 1820, 1910) having a receiving section (130, 230, 330, 430, 1030) configured to receive a DUT (150, 250, 350, 450, 550, 1620, 1720, 2150 ), wherein the pusher is configured to push the DUT towards the receiving section or to push the DUT into the receiving section; and wherein the pusher is at least partially surrounded by an electromagnetic absorber,2. The DUT socket structure according to claim 1 , wherein the DUT socket comprises one or more side walls (180) surrounding the receiving section, wherein a surface of the one or more side walls facing towards the receiving section is at least partially covered by an electromagnetic absorber.

3. The DUT socket structure according to claim 1 , wherein the DUT socket comprises a one or more side walls surrounding the receiving section, wherein the side walls decline towards the receiving section.

4. The DUT socket structure according to any of the claims 1 to 3, wherein a lateral surface of the pusher is fully surrounded by the electromagnetic absorber at least over a part of a longitudinal extension of the pusher.

5. The DUT socket structure according to any of the claims 1 to 4, wherein a surface of the electromagnetic absorber facing towards the pusher comprises a plurality of pyramid-like structures (246, 640, 830, 1360, 1783) or cone-like structures (243, 640, 830).

6. The DUT socket structure according to claim 5, wherein a height of the pyramid-like structures or cone-like structures is within a range between 0.1 times a wavelength ata lowest frequency of operation and 0.4 times a wavelength at a lowest frequency of operation, or wherein the height of the pyramid-like structures or cone-like structures is within a range between 0.2 times a wavelength at a lowest frequency of operation and 0.3 times a wavelength at a lowest frequency of operation.

7. The DUT socket structure according to claim 5 or 6, wherein an area of the base of the pyramid-like structures or of the cone-like structures is within a range of 0.2-0.4 times the square of the wavelength at a lowest frequency of operation.

8. The DUT socket structure according to one of claims 1 to 7, wherein the electromagnetic absorber is arranged to surround a portion of the pusher, with a spacing in between the electromagnetic absorber and the pusher.

9. The DUT socket structure according to any of the claims 1 to 8, wherein, in a portion in which the electromagnetic absorber surrounds the pusher with a spacing in between, the distance between the electromagnetic absorber and the pusher is within a range between 0.2 times a wavelength at a lowest frequency of operation and 0.8 times a wavelength at a lowest frequency of operation, or wherein, in a portion in which the electromagnetic absorber surrounds the pusher with a spacing in between, the distance between the electromagnetic absorber and the pusher is within a range between 0.1 times a wavelength at a lowest frequency of operation and 0.6 times a wavelength at a lowest frequency of operation.

10. The DUT socket structure according to one of claims 1 to 9, wherein an electromagnetic absorber is arranged between the pusher and a positioning structure (910, 1960) of the DUT socket structure; and / or wherein an electromagnetic absorber is arranged between the pusher and a fixing structure of the DUT socket structure; and / orwherein an electromagnetic absorber is arranged between the pusher and a waveguide structure of the DUT socket structure.

11. A test arrangement (200, 300, 360, 390, 400, 500, 720, 920, 1300, 1610, 1670, 1675, 1710, 1770, 1775, 1810, 2040, 2100) comprising a DUT socket structure according to any of the claims 1 to 10 and a measurement antenna structure (270, 370, 375, 470, 570, 1660, 1760, 1830), wherein the pusher is arranged between the measurement antenna structure and the receiving section.

12. The test arrangement according to claim 11 , wherein the test arrangement comprises a further electromagnetic absorber portion (293, 296, 490, 1330) with an opening (299, 495), wherein the further electromagnetic absorber portion is arranged to at least partially cover a surface of a conductive structure comprising the measurement antenna structure or carrying the measurement antenna structure, wherein the surface of the conductive structure is facing towards the receiving section; wherein the further electromagnetic absorber portion is arranged between the conductive structure (275, 475, 575) and a portion of a surface of the pusher, such that the opening is located on an electromagnetic propagation path (280, 380, 385, 480, 2140) between the measurement antenna structure and the receiving section.

13. The test arrangement according to claim 11 or 12, wherein the pusher comprises a widening (215, 1320) at a longitudinal portion near to the measurement antenna structure, and wherein a surface on the receiving section side of the widening is covered by an electromagnetic absorber portion.

14. An automated test equipment comprising a test arrangement according to any of the claims 11 to 13 or a test cell (1650, 1750, 1950) comprising a plurality of test arrangements according to any of the claims 11 to 13.

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