PATENT DOCUMENT

Publication Number: US-9128118-B2
Application Number: US-201213590963-A
Country: US
Kind Code: B2

Title: Testing systems with automated loading equipment and positioners

Abstract:
A test system may be provided in which devices under test are tested using radio-frequency test stations. A test station may include a test host, a test unit coupled to the test host, and a shielded enclosure. The shielded enclosure may contain a test antenna coupled to the test unit via a radio-frequency cable. A computer-controlled loading arm may be used to place a device under test on a positioner within the test enclosure. The test enclosure may have an enclosure door that is opened and closed using a computer-controlled pneumatic cylinder. When the enclosure door is closed, a portion of the enclosure door may actuate one or more levers on the positioner, which may in turn actuate one or more positioning arms to press the device under test against one or more guide surfaces on the positioner, thereby precisely positioning the device under test within the test enclosure.

Claims:
What is claimed is: 
     
       1. Test apparatus for testing a device under test, comprising:
 a test enclosure having an enclosure door; and 
 a positioner in the test enclosure that is configured to receive the device under test, wherein the positioner includes at least one positioning arm, an actuating member that controls the positioning arm, and at least two guide surfaces against which the device under test is pressed, the positioner being configured to automatically position the device under test as a result of closing the enclosure door. 
 
     
     
       2. The test apparatus defined in  claim 1 , further comprising:
 a computer-controlled door actuator coupled to the enclosure door, wherein the computer-controlled door actuator is configured to control movement of the enclosure door. 
 
     
     
       3. The test apparatus of  claim 2 , wherein the computer-controlled door actuator comprises a pneumatic cylinder. 
     
     
       4. The test apparatus of  claim 1 , further comprising:
 a computer-controlled loading arm configured to place the device under test on the positioner. 
 
     
     
       5. The test apparatus of  claim 4 , wherein the computer-controlled loading arm comprises at least one pneumatic port configured to temporarily adhere the device under test to the computer-controlled loading arm. 
     
     
       6. The test apparatus of  claim 1 , wherein the at least one positioning arm is configured to press the device under test against the at least two guide surfaces. 
     
     
       7. The test apparatus of  claim 1 , wherein the at least one positioning arm comprises polyetheretherketone. 
     
     
       8. The test apparatus of  claim 1 , further comprising:
 a test unit coupled to the test enclosure, wherein the test unit is configured to perform testing on the device under test when the device under test is within the test enclosure. 
 
     
     
       9. A method for testing a device under test in a test system that includes a test enclosure and a test unit coupled to the test enclosure, comprising:
 with a computer-controlled loading arm in the test system, placing the device under test on a positioner within the test enclosure; 
 closing the test enclosure; 
 in response to closing the test enclosure, automatically positioning the device under test using the positioner, wherein automatically positioning the device under test in response to closing the test enclosure comprises actuating at least one actuating member on the positioner as a result of closing the test enclosure; and 
 when the device is properly positioned within the test enclosure, testing the device under test using the test unit. 
 
     
     
       10. The method defined in  claim 9 , wherein closing the test enclosure comprises actuating a pneumatic cylinder that is coupled to the test enclosure. 
     
     
       11. The method defined in  claim 9 , wherein automatically positioning the device under test in response to closing the test enclosure comprises automatically pressing the device under test against at least one guide surface on the positioner using at least one positioning arm on the positioner. 
     
     
       12. The method defined in  claim 9 , wherein testing the device under test comprises conveying test signals between the test unit and the device under test. 
     
     
       13. The method defined in  claim 9 , further comprising:
 with the computing equipment, directing the computer-controlled loading arm to remove the device under test from the test enclosure following testing. 
 
     
     
       14. Test apparatus for testing a device under test, comprising:
 an electromagnetically shielded test enclosure that is configured to be opened and closed; 
 a test unit that is coupled to the electromagnetically shielded test enclosure and that is configured to perform testing on the device under test; and 
 a dielectric support structure within the electromagnetically shielded test enclosure, the dielectric support structure comprising a positioning arm, an actuating member that controls the positioning arm, and at least two guide surfaces against which the device under test is pressed, wherein the dielectric support structure is configured to receive the device under test and to automatically position the device under test in a predetermined location within the electromagnetically shielded test enclosure as a result of the electromagnetically shielded test enclosure being closed. 
 
     
     
       15. The test apparatus defined in  claim 14 , wherein the positioning arm is configured to automatically press the device under test against a first one of the at least two guide surfaces. 
     
     
       16. The test apparatus defined in  claim 15 , wherein the dielectric support structure further comprises and an additional movable positioning arm, wherein the additional movable positioning arm is configured to automatically press the device under test against a second one of the at least two guide surfaces. 
     
     
       17. The test apparatus defined in  claim 14 , wherein the actuating member comprises a lever, wherein the electromagnetically shielded test enclosure comprises a test enclosure door operable to be opened and closed, and wherein a portion of the test enclosure door actuates the lever on the dielectric support structure when the enclosure door is closed. 
     
     
       18. The test apparatus defined in  claim 17 , wherein the positioning arm is configured to press against the device under test when the lever is actuated to position the device under test in the predetermined location. 
     
     
       19. The test apparatus defined in  claim 14 , wherein the electromagnetically shielded test enclosure comprises a test antenna configured to convey radio-frequency test signals between the test unit and the device under test during testing.

Description:
BACKGROUND 
     This relates generally to testing systems, and, more particularly, to testing systems that use automated loading equipment and positioning structures. 
     Electronic devices are often tested following assembly to ensure that device performance meets design specifications. For example, a device may be tested at a series of test stations to ensure that components and software in the device are operating satisfactorily. At each test station, a test system operator may place a device under test into a test enclosure. The position and orientation of a device under test within a test enclosure needs to be precise in order to ensure that test results are accurate. Following testing at a given test station, the test system operator may remove the device under test from the test enclosure. Following successful testing at all test stations, a device may be shipped to an end user. 
     The process of loading and unloading devices under test from test enclosures can be cumbersome and burdensome to test system operators. If care is not taken, a device under test may be improperly positioned within a test enclosure, which may in turn lead to inaccurate or skewed test results. Additionally, excessive contact between a test system operator and a device under test may increase the risk of cosmetic damage to the device under test. 
     It would therefore be desirable to be able to provide improved ways of performing manufacturing operations such as testing operations on electronic devices. 
     SUMMARY 
     A test system may be provided in which radio-frequency test stations are used to perform wireless testing on devices under test. Test apparatus may include a test host, a test unit, and an electromagnetically shielded test enclosure (e.g., a shielded test box such as a transverse electromagnetic cell or other suitable type of test box or test chamber). 
     The test system may include a computer-controlled loading arm configured to convey devices under test between test input locations, test output locations, and test enclosures. The computer-controlled loading arm may have pneumatic ports that may be used to temporarily adhere a device under test to the computer-controlled loading arm. The computer-controlled loading arm may be used to load devices under test into test enclosures. 
     A dielectric support structure may be mounted in each test enclosure and may be configured to receive a device under test. The dielectric support structure may function as a positioner in which one or more positioning arms are used to press the device under test against one or more guide surfaces. For example, a first positioning arm may press the device under test against a first guide surface, while a second positioning arm may press the device under test against a second guide surface, thereby precisely positioning the device under test in a predetermined location. 
     The positioner may have one or more levers that may be used to control the movement of the positioning arms. The levers may be actuated by closing the test enclosure door. For example, a door to the test enclosure may have portions that actuate the levers on the positioner when the door is closed. With this type of configuration, closing the test enclosure may automatically actuate the positioner to position the device under test in a precise location within the test enclosure. 
     The test enclosure door may be opened and closed using a computer-controlled door actuator. The computer-controlled door actuator may include, for example, a pneumatic cylinder. 
     When the device under test is properly positioned, the test unit may perform testing on the device under test. This may include, for example, using a test antenna coupled to the test enclosure to convey radio-frequency test signals between the test unit and the device under test. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device such as a handheld device of the type that may be manufactured using automated equipment in accordance with an embodiment of the present invention. 
         FIG. 2  is a diagram of a wireless network including a base station and an illustrative electronic device having wireless communications circuitry in accordance with an embodiment of the present invention. 
         FIG. 3  is a diagram of an illustrative test system that may be used to perform over-the-air testing in accordance with an embodiment of the present invention. 
         FIG. 4  is a cross-sectional side view of an illustrative test enclosure in which a positioner and device under test have been placed in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an illustrative test enclosure in which the enclosure door is located in a closed position in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of an illustrative test enclosure in which an actuating member has been actuated to move the enclosure door into an open position in accordance with an embodiment of the present invention. 
         FIG. 7  is a perspective view of an illustrative positioner that may be used to precisely position a device under test in accordance with an embodiment of the present invention. 
         FIG. 8  is a cross-sectional side view of an illustrative positioner in which a device under test has been mounted in accordance with an embodiment of the present invention. 
         FIG. 9  is a diagram showing how a single positioning arm may be used to press a device under test against two datums in a positioner in accordance with an embodiment of the present invention. 
         FIG. 10  is a diagram showing how two positioning arms may be used to press a device under test against two datums in a positioner in accordance with an embodiment of the present invention. 
         FIG. 11  is a diagram showing how two positioning arms may be used to press a device under test against two datums in a positioner in accordance with an embodiment of the present invention. 
         FIG. 12  is a perspective view of an illustrative test enclosure having mounting structures in accordance with an embodiment of the present invention. 
         FIG. 13  is a cross-sectional side view showing how a positioner may be mounted on a floor surface of a test enclosure in accordance with an embodiment of the present invention. 
         FIG. 14  is a perspective view of an illustrative computer-controlled loading arm that may be used to transfer devices under test to and from test input/output locations in accordance with an embodiment of the present invention. 
         FIG. 15  is a flow chart of illustrative steps involved in testing devices under test using test enclosures, automated loading equipment, and automated positioners in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be manufactured using automated manufacturing equipment. The automated manufacturing equipment may include equipment for assembling device components together to form an electronic device. The automated manufacturing equipment may also include testing systems for evaluating whether devices have been properly assembled and are functioning properly. 
     Electronic devices may be provided with wireless communications circuitry. The wireless communications circuitry may be used to support wireless communications in multiple wireless communications bands. The wireless communications circuitry may include multiple transmit and receive antennas arranged to implement an antenna diversity system. 
     The antennas can include loop antennas, inverted-F antennas, strip antennas, planar inverted-F antennas, slot antennas, hybrid antennas that include antenna structures of more than one type, or other suitable antennas. Conductive structures for the antennas may be formed from conductive electronic device structures such as conductive housing structures (e.g., a ground plane and part of a peripheral conductive housing member or other housing structures), traces on substrates such as traces on plastic, glass, or ceramic substrates, traces on flexible printed circuit boards (“flex circuits”), traces on rigid printed circuit boards (e.g., fiberglass-filled epoxy boards), sections of patterned metal foil, wires, strips of conductor, other conductive structures, or conductive structures that are formed from a combination of these structures. 
     Wireless communications circuitry in an electronic device may be tested using automated equipment. An illustrative electronic device of the type that may be manufactured and tested using automated equipment is shown in  FIG. 1 . Electronic device  10  of  FIG. 1  may be a computer monitor with an integrated computer, a desktop computer, a television, a notebook computer, other portable electronic equipment such as a cellular telephone, a tablet computer, a media player, a wrist-watch device, a pendant device, an earpiece device, other compact portable devices, or other electronic equipment. In the configuration shown in  FIG. 1 , device  10  is a handheld electronic device such as a cellular telephone, media player, navigation system device, or gaming device. 
     As shown in  FIG. 1 , device  10  may include a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material. In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may be a touch screen that incorporates capacitive touch electrodes or may be insensitive to touch. Display  14  may include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrophoretic display elements, electrowetting display elements, liquid crystal display (LCD) components, or other suitable image pixel structures. A cover glass layer may cover the surface of display  14 . Openings for buttons such as button  20 , openings for speaker ports such as speaker port  22 , and other openings may be formed in the cover layer of display  14 , if desired. 
     The central portion of display  14  (e.g., active region  16 ) may include active image pixel structures. The surrounding rectangular ring-shaped inactive region (region  18 ) may be devoid of active image pixel structures. If desired, the width of inactive region  18  may be minimized (e.g., to produce a borderless display). 
     Device  10  may include components such as front-facing camera  24 . Camera  24  may be oriented to acquire images of a user during operation of device  10 . Device  10  may include sensors in portion  26  of inactive region  18 . These sensors may include, for example, an infrared-light-based proximity sensor that includes an infrared-light emitter and a corresponding light detector to emit and detect reflected light from nearby objects. The sensors in portion  26  may also include an ambient light sensor for detecting the amount of light that is in the ambient environment for device  10 . Other types of sensors may be used in device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     Device  10  may include input-output ports such as port  28 . Ports such as port  28  may include audio input-output ports, analog input-output ports, digital data input-output ports, or other ports. Each port may have an associated connector. For example, an audio port may have an associated four-contact audio connector, a digital data port may have a connector with two or more pins (contacts), a connector with four or more pins, a connector with thirty pins, or other suitable data port connector. 
     Sensors such as the sensors associated with region  26  of  FIG. 1 , cameras such as camera  24 , audio ports such as speaker port  22 , buttons such as button  20 , and ports such as port  28  may be located on any suitable portion of device housing  12  (e.g., a front housing face such as a display cover glass portion, a rear housing face such as a rear planar housing wall, sidewall structures, etc.). 
     Housing  12  may include a peripheral conductive member such as a bezel or band of metal that runs around the rectangular outline of display  14  and device  10  (as an example). The peripheral conductive member may be used in forming the antennas of device  10  if desired. 
     Antennas may be located along the edges of device  10 , on the rear or front of device  10 , as extending elements or attachable structures, or elsewhere in device  10 . With one suitable arrangement, which is sometimes described herein as an example, device  10  may be provided with one or more antennas at lower end  17  of housing  12  and one or more antennas at upper end  15  of housing  12 . Locating antennas at opposing ends of device  10  may allow these antennas to be formed at an appropriate distance from ground structures that are associated with the conductive portions of display (e.g., the pixel array and driver circuits in active region  16  of display  14 ). 
     If desired, a first cellular telephone antenna may be located in region  17  and a second cellular telephone antenna may be located in region  15 . Antenna structures for handling satellite navigation signals such as Global Positioning System signals or wireless local area network signals such as IEEE 802.11 (WiFi®) signals or Bluetooth® signals may also be provided in regions  15  and/or  17  (either as separate additional antennas or as parts of the first and second cellular telephone antennas). Antenna structures may also be provided in regions  15  and/or  17  to handle WiMax (IEEE 802.16) signals. 
     In regions  15  and  17 , openings may be formed between conductive housing structures and printed circuit boards and other conductive electrical components that make up device  10 . These openings may be filled with air, plastic, or other dielectrics. Conductive housing structures and other conductive structures may serve as a ground plane for the antennas in device  10 . The openings in regions  15  and  17  may serve as slots in open or closed slot antennas, may serve as a central dielectric region that is surrounded by a conductive path of materials in a loop antenna, may serve as a space that separates an antenna resonating element such as a strip antenna resonating element or an inverted-F antenna resonating element such as an inverted-F antenna resonating element formed from part of a conductive peripheral housing structure in device  10  from the ground plane, or may otherwise serve as part of antenna structures formed in regions  15  and  17 . 
     Antennas formed in regions  15  and  17  may be identical (i.e., antennas formed in regions  15  and  17  may each cover the same set of cellular telephone bands or other communications bands of interest). Due to layout constraints or other design constraints, it may not be desirable to use identical antennas. Rather, it may be desirable to implement the antennas in regions  15  and  17  using different designs. For example, a first antenna in region  17  may cover all cellular telephone bands of interest (e.g., four or five bands) and a second antenna in region  15  may cover a subset of the four or five bands handled by the first antenna. Arrangements in which the antenna in region  17  handles a subset of the bands handled by the antenna in region  15  may also be used. Tuning circuitry may be used to tune this type of antenna in real time to cover either a first subset of bands or a second subset of bands and thereby cover all bands of interest. 
     To reliably receive incoming voice or data calls, device  10  should be able to receive incoming paging signals. In some situations, incoming paging signals are weak due to interference or a relatively large distance between device  10  and the transmitting cellular telephone tower. In situations such as these, multiple antennas (e.g., both antennas in a dual antenna system) may be used in receiving paging signals. Combining received signals from multiple antennas can improve received signal quality and can therefore help ensure that incoming pages are received properly, even in areas with weak signals. Use of dual antennas in receiving signals generally consumes more power than use of a single antenna in receiving signals. Device  10  may therefore revert to using only a single antenna whenever signal conditions improve. 
     An antenna switching algorithm that runs on the circuitry of device  10  can be used to automatically change between antenna modes in real time based on the evaluated signal quality of received signals. The antenna switching algorithm may direct device  10  to operate in a multiple antenna mode (e.g., a dual antenna mode) when incoming signals are weak and may direct device  10  to operate in a single antenna mode when incoming signals are strong (as an example). With this type of arrangement, it is not necessary to simultaneously use multiple antennas and associated receiver circuits for monitoring incoming paging signals except when paging signals are of poor quality, thereby minimizing power consumption. 
     Arrangements in which device  10  has a primary antenna (e.g., an antenna that typically exhibits superior performance) and a secondary antenna (e.g., an antenna whose performance typically does not exceed that of the primary antenna) are sometimes described herein as an example. This is, however, merely illustrative. Device  10  may use three or more antennas if desired. Device  10  may use antennas that are substantially identical (e.g., in band coverage, in efficiency, etc.), or may use other types of antenna configurations. 
     When operating in single antenna mode, either the primary or the secondary antenna may be used. For example, device  10  may default to use of the primary antenna whenever changing to single antenna mode from dual antenna mode while monitoring paging signals. If desired, device  10  may select an optimum antenna to use when transitioning from dual antenna mode to single antenna mode. Device  10  may select the optimum antenna by evaluating the signal strength on each antenna and choosing the antenna with the strongest signal or by using other suitable antenna selection criteria. 
     A schematic diagram of a system in which electronic device  10  may operate is shown in  FIG. 2 . As shown in  FIG. 2 , system  11  may include wireless network equipment such as base station  21 . Base stations such as base station  21  may be associated with a cellular telephone network or other wireless networking equipment. Device  10  may communicate with base station  21  over wireless link  23  (e.g., a cellular telephone link or other wireless communications link). 
     Device  10  may include control circuitry such as storage and processing circuitry  28 . Storage and processing circuitry  28  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  28  and other control circuits such as control circuits in wireless communications circuitry  34  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips, application specific integrated circuits, etc. 
     Storage and processing circuitry  28  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment such as base station  21 , storage and processing circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry  28  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, IEEE 802.16 (WiMax) protocols, cellular telephone protocols such as the Long Term Evolution (LTE) protocol, Global System for Mobile Communications (GSM) protocol, Code Division Multiple Access (CDMA) protocol, and Universal Mobile Telecommunications System (UMTS) protocol, etc. 
     Circuitry  28  may be configured to implement control algorithms that control the use of antennas in device  10 . For example, circuitry  28  may configure wireless circuitry  34  to switch a particular antenna into use for transmitting and/or receiving signals or may switch multiple antennas into use simultaneously. In some scenarios, circuitry  28  may be used in gathering sensor signals and signals that reflect the quality of received signals (e.g., received paging signals, received voice call traffic, received control channel signals, received data traffic, etc.). Examples of signal quality measurements that may be made in device  10  include bit error rate measurements, signal-to-noise ratio measurements, measurements on the amount of power associated with incoming wireless signals, channel quality measurements based on received signal strength indicator (RSSI) information (RSSI measurements), channel quality measurements based on received signal code power (RSCP) information (RSCP measurements), channel quality measurements based on signal-to-interference ratio (SINR) and signal-to-noise ratio (SNR) information (SINR and SNR measurements), channel quality measurements based on signal quality data such as Ec/lo or Ec/No data (Ec/lo and Ec/No measurements), etc. This information may be used in controlling which antenna mode is used (e.g., single antenna mode or dual antenna mode) and may be used in selecting an optimum antenna in single antenna mode (if desired). Antenna selections can also be made based on other criteria. 
     Input-output circuitry  30  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output circuitry  30  may include input-output devices  32 . Input-output devices  32  may include touch screens, buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output devices  32  and may receive status information and other output from device  10  using the output resources of input-output devices  32 . 
     Wireless communications circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas, and other circuitry for handling RF wireless signals. 
     Wireless communications circuitry  34  may include satellite navigation system receiver circuitry such as Global Positioning System (GPS) receiver circuitry  35  (e.g., for receiving satellite positioning signals at 1575 MHz). Transceiver circuitry  36  may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and may handle the 2.4 GHz Bluetooth® communications band. Circuitry  34  may use cellular telephone transceiver circuitry  38  for handling wireless communications in cellular telephone bands such as bands at 700 MHz, 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, and 2100 MHz or other cellular telephone bands of interest. Wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired (e.g., WiMax circuitry, etc.). Wireless communications circuitry  34  may, for example, include wireless circuitry for receiving radio and television signals, paging circuits, etc. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. 
     Wireless communications circuitry  34  may include antennas  40 . Antennas  40  may be formed using any suitable types of antenna. For example, antennas  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, closed and open slot antenna structures, planar inverted-F antenna structures, helical antenna structures, strip antennas, monopoles, dipoles, hybrids of these designs, etc. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. As described in connection with  FIG. 1 , there may be multiple cellular telephone antennas in device  10 . For example, there may be one cellular telephone antenna in region  17  of device  10  and another cellular telephone antenna in region  15  of device  10 . These antennas may be fixed or may be tunable. 
     During testing, many wireless devices (e.g., tens, hundreds, thousands, or more of devices  10 ) may be tested in a test system such as test system  100  of  FIG. 3 . Electronic devices that are being tested in test system  100  may sometimes be referred to as devices under test (DUTs). Test system  100  may include test accessories, computers, network equipment, tester control boxes, cabling, test enclosures, and other test equipment for generating and receiving radio frequency test signals and gathering test results. Test system  100  may include multiple test stations such as test stations  102 . There may, for example, be eighty test stations  102  at a given test site. Test system  100  may include any desired number of test stations to achieve desired test throughput. 
     Each test station  102  may include a test host such as test host  103 , a tester such as test unit  106 , and a test enclosure such as test enclosure  110 . Test host  104  may, for example, be a personal computer or other type of computing equipment. Test unit  106  may be a signal generator, a spectrum analyzer, a vector network analyzer, and other testers suitable for generating radio-frequency test signals and for performing radio-frequency measurements on signals received from DUT  10 . In other suitable arrangements, test unit  106  may be a radio communications tester of the type that is sometimes referred to as a call box or a base station emulator. Test unit  106  may, for example, be the CMU300 Universal Radio Communication Tester available from Rohde &amp; Schwarz. Test unit  106  may be used to emulate the behavior of a base transceiver station during a telephone call with cellular telephone transceiver circuitry  38  to test the ability of transceiver  38  to support “2G” cellular telephone communications protocols such as the 2G GSM and 2G CDMA, 3G Cellular telephone communications protocols such as UMTS and Evolution-Data Optimized (EVDO), 4G cellular telephone communications protocols such as LTE, and other suitable cellular telephone communications protocols. If desired, test unit  106  may be configured to emulate the behavior of a network access point to test the ability of transceiver  36  to support the WiFi® communications protocol, the Bluetooth® communications protocol, or other short-range wireless communications standards. 
     Test unit  106  may be operated directly or via computer control (e.g., when test unit  106  receives commands from test host  104 ). When operated directly, a user may control test unit  106  by supplying commands directly to test unit  106  using the user input interface of test unit  106 . For example, a user may press one or more buttons in a control panel on the test unit while viewing information that is displayed on a display in test unit  106 . In computer-controlled configurations, test host  104  (e.g., software running autonomously or semi-autonomously on the computer) may communicate with test unit  106  by sending and receiving data over a wired path  104  or a wireless path between the computer and the test unit (as an example). 
     During testing, at least one DUT  10  may be placed within test enclosure  110 . DUT  10  may optionally be coupled to test host  104  via control line  116 . The connection represented by line  116  may be a Universal Serial Bus (USB) based connection, a Universal Asynchronous Receiver/Transmitter (UART) based connection, or other suitable type of connection. During testing, test host  104  may send control signals to DUT  10  and may retrieve test data from DUT  10  via connection  116 . Electrically connecting DUT  10  to test host  104  via connection  116  is, however, optional. If desired, DUT  10  may not be electrically connected to test host  104 . 
     Test enclosure  110  may be a shielded enclosure (e.g., a shielded test box or test cell) that can be used to provide radio-frequency isolation when performing electromagnetic compatibility (EMC) radiated tests without experiencing interference from outside environment. Test enclosure  110  may, for example, be a transverse electromagnetic (TEM) cell. The interior or test enclosure  110  may be lined with radio-frequency absorption material such as rubberized foam configured to minimize reflections of wireless signals. 
     Test enclosure  110  may include in its interior wireless structures for communicating over short distances using near field electromagnetic coupling (e.g., over ten centimeters or less). Wireless structures in test enclosure  110  may include an inductor or other near field communications element (sometimes referred to as a near field communications test antenna or near field communications coupler) used to radiate corresponding near field electromagnetic signals to DUT  10 . A test antenna such as test antenna  114  may be coupled to test unit  106  via a radio-frequency cable such as radio frequency cable  112  (e.g., a coaxial cable). Test antenna  114  may be used during production test procedures to perform over-the-air testing on DUT  10  (e.g., so that radio-frequency test signals may be conveyed between test unit  106  and DUT  10  via antenna  114 ). Test antenna  114  may, as an example, be a microstrip antenna such as a microstrip patch antenna. 
     During testing, downlink test signals may be conveyed from test antenna  114  to DUT  10  in the direction of arrow  230 , whereas uplink test signals may be conveyed from DUT  10  to test antenna  114  in the direction of arrow  232 . Test radio-frequency signals may be conveyed between test unit  106  and DUT  10  over a non-protocol-compliant communications path (e.g., an unauthenticated wireless communications data link) or a protocol-compliant communications link (e.g., an authenticated wireless communications link). 
     DUT  10  may be loaded with a test system operating system (e.g., a simplified operating system that lacks a full Internet Protocol (IP) stack implementation) or a normal user operating system (e.g., an operating system that includes a full Internet Protocol (IP) stack implementation. DUT  10  may include wireless performance measurement circuitry capable of analyzing the received test signals. As discussed previously, DUT  10  may be capable of computing and storing radio-frequency downlink metrics such as bit error rate measurements, signal-to-noise ratio measurements, measurements on the amount of power associated with incoming wireless signals, channel quality measurements based on received signal strength indicator (RSSI) information, channel quality measurements based on received signal code power (RSCP) information, channel quality measurements based on signal-to-interface ratio (SINR) and signal-to-noise ratio (SNR) information, channel quality measurements based on signal quality data such as Ec/lo or Ec/No data, etc. 
     As shown in  FIG. 3 , each test station  102  may be connected to computing equipment  118  through line  120 . Computing equipment  118  may include storage equipment on which a database such as database  122  is stored. After desired radio-frequency measurements have been gathered from DUT  10 , DUT  10  may be removed from test enclosure  110 . Test data may then be loaded onto associated test host  104 . The test data gathered at the different test stations  102  may be stored centrally in database  122 . 
     Test system  100  may include a system of automated structures that may be used to facilitate testing of DUTs  10 . The system of automated structures may include automated loading equipment, actuating members, positioning equipment, computer-controlled structures, etc. The system of automated structures may increase accuracy and throughput of test system  100 . 
     The system of automated structures may include, for example, automated positioning equipment such as positioner  42 . As shown in  FIG. 3 , each test enclosure  110  may be provided with a positioner  42  that may be used to accurately and precisely position DUT  10  within test enclosure  110 . Positioning each DUT  10  in a predetermined location within test enclosure  110  may ensure that test results gathered from different DUTs using that particular test station are comparable. When it is desired to test DUT  10  at test station  102 , DUT  10  may be placed on positioner  42  within test enclosure  110 . Positioner  42  may include one or more positioning arms that may be used to press DUT  10  against guide surfaces (sometimes referred to as datums) in positioner  42 , thereby positioning DUT  10  in a precise location. 
     The positioning arms on positioner  42  may be actuated by one or more actuating members on positioner  42 . The actuating members on positioner  42  may be actuated automatically (e.g., using automated equipment). The actuating members on positioner  42  may, for example, be actuated by an enclosure door associated with enclosure  110 . For example, the door to test enclosure  110  may have one or more portions that make contact with the actuating members on positioner  42  when the enclosure door is closed. Closing the enclosure door may therefore actuate the positioning arms on positioner  42  to press DUT  10  against the guide surfaces in positioner  42 . This is, however, merely illustrative. If desired, other automated or robotic structures may be used to actuate positioning arms on positioner  42  or to otherwise precisely position DUT  10  within test enclosure  110 . 
     The system of automated structures associated with test system  100  may also include automated loading equipment such as computer-controlled loading arms. Computer-controlled loading arms may be used to convey DUTs between test input locations, test output locations, and test enclosures. The system of automated structures may also include actuating members such as air-driven and motor-driven actuators. For example, an actuating member may be coupled to the door of each test enclosure  110  and may be used to control the opening and closing of the enclosure door. 
     The system of automated structures in test system  100  may be controlled by computing equipment  118 , may be controlled by test host  104 , or may be controlled by other computer-based control systems. If desired, some automated structures may be controlled by computing equipment  118 , while other automated structures may be controlled by test host  104 . For example, actuating members associated with each test enclosure  110  may be controlled by test host  104 , whereas loading arms responsible for conveying DUTs between test stations may be controlled by computing equipment  118 . This is, however, merely illustrative. In general, any suitable arrangement of computer-based control systems may be used to control the system of automated structures associated with test system  100 . 
       FIG. 4  is a cross-sectional side view of an illustrative test enclosure in which a positioner and DUT have been placed. As discussed above in connection with  FIG. 3 , test enclosure  110  may be a shielded enclosure that may be used to provide radio-frequency isolation when performing electromagnetic compatibility (EMC) radiated tests without experiencing interference from outside environment. Test enclosure may have any suitable shape. In the example of  FIG. 4 , test enclosure  110  has a pyramid-like shape in which a base portion such as base portion  74  is surrounded by four walls that converge at the top of the enclosure. This is, however, merely illustrative. If desired, test enclosure  110  may have a cylinder-like shape, a cube-like shape, other prism-like shape, etc. 
     As shown in  FIG. 4 , test enclosure  110  may include an opening such as opening  76 . DUTs may be loaded into and removed from enclosure  110  via opening  76 . An enclosure door such as enclosure door  44  may be used to seal opening  76  while tests are being performed on DUT  10  in enclosure  110 . 
     Positioning equipment such as positioner  42  may be mounted on base portion  74  of enclosure  110 . Fastening structures such as fastening structures  80  may be used to secure base portion  82  of positioner  42  to base portion  74  of test enclosure  110 . Fastening structures  80  may include screws, standoffs, threaded standoffs, and/or other attachment mechanisms that may be used to secure positioner  42  to base  74  of enclosure  110 . If desired, fastening structures  80  may have portions that extend into support structures  78  underneath enclosure  110 . 
     Positioner  42  (sometimes referred to as a dielectric support structure) may be configured to receive DUT  10 , to precisely position DUT  10  prior to testing, and to support DUT  10  during testing. To support DUT  10  and to accurately place DUT  10  in a precise location along the Z axis, positioner  42  may include one, two, three, or more than three support surfaces such as support surface  84 A on which DUT  10  rests. To accurately place DUT  10  in a precise location along the X and Y axes, positioner  42  may include two or more guide surfaces (datums) such as guide surface  86 A against which DUT  10  may be pressed. One or more positioning arms such as positioning arm  60  may be use to press DUT  10  against guide surfaces such as guide surface  86 A, thereby placing DUT  10  in a precise location (e.g., a precise location along the X, Y, and Z axes). 
     Positioning arms on positioner  42  such as positioning arm  60  may be controlled by one or more actuating members on positioner  42  such as actuating member  58 . By pressing down on actuating member  58  in direction  88 , positioning arm  60  may be moved into the position shown in  FIG. 4  (e.g., may be moved towards device  10  in direction  90 ). Enclosure door  44  may have a protruding portion such as portion  46  that may be used to actuate actuating member  58  when enclosure door  44  is in a closed position. Closing enclosure door  44  may therefore actuate positioning arm  60  to press DUT  10  against guide surface  86 A. 
     The opening and closing of enclosure door  44  may be computer-controlled. For example, as shown in  FIG. 4 , a computer-controlled door actuator such as door actuator  48  may be mechanically coupled to enclosure door  44  and may be used to open and close door  44 . Door actuator  48  may, for example, be a pneumatic cylinder having first and second portions  48 A and  48 B. First portion  48 A may be a tube filled with a variable amount of compressed air. Second portion  48 B (sometimes referred to as a piston) may be configured to extend out from portion  48 A (e.g., in direction  52 ) and to retract into portion  48 A (e.g., in direction  50 ). As the compressed air in portion  48 A expands, piston  48 B may be forced outward in direction  52 . Piston  48 B may be retracted back into air tube  48 A using any suitable means (e.g., using force provided by air, using force provided by a spring, etc.). 
     In addition to expanding and contracting, door actuator  48  may be configured to rotate about pivot point  92  to facilitate opening and closing of enclosure door  44 . When it is desired to open door  44 , portion  48 B may retract into portion  48 A of actuator  48  while, at the same time, end portion  94  of actuator  48  moves downward in direction  56 . This may in turn move enclosure door  44  outward in direction (e.g., away from opening  76 ). When it is desired to close door  44 , portion  48 B may expand outward from portion  48 A of actuator  48  while, at the same time, end portion  94  of actuator  48  moves upward in direction  54 . This may in turn move enclosure door  44  inward in direction  72  (e.g., towards openings  76 ). Door actuator  48  may be controlled by a central control system (e.g., by computing equipment  118  of  FIG. 3 ). 
     If desired, other types of actuators may be used to open and close enclosure door  44  (e.g., motor-driven actuators, other types of air-driven actuators, etc.). The example in which actuator  48  is formed from a pneumatic cylinder is merely illustrative. 
       FIGS. 5 and 6  are cross-sectional side views of enclosure  110  showing how enclosure door  44  may be operated. In the example of  FIG. 5 , enclosure door  44  is in a closed position (e.g., similar to the position shown in  FIG. 4 ). In the closed position, portion  48 B of door actuator  48  may be extended out from portion  48 A of actuator  48 . 
     When it is desired to open enclosure door  44 , portion  48 B may begin to retract into portion  48 A, as shown in  FIG. 6 . While portion  48 B retracts into portion  48 A in direction  97 , actuator  48  may simultaneously rotate about pivot point  92  (e.g., in a counterclockwise direction), thereby moving end portion  94  of actuator  48  downwards in direction  98 . Angle  96  may remain fixed such that, as end portion  94  of actuator  48  moves in direction  97  and in direction  98 , door  44  is moved in direction  99  (e.g., away from enclosure  110 ). 
     When it is desired to close enclosure door  44 , portion  48 B may begin to extend outward from portion  48 A. While portion  48 B extends outward from portion  48 A in direction  103 , actuator  48  may simultaneously rotate about pivot point  92  (e.g., in a clockwise direction), thereby moving end portion  94  of actuator  48  upwards in direction  105 . Because angle  96  remains fixed, door  44  may be moved in direction  101  (e.g., towards enclosure  110 ) as end portion  94  of actuator  48  moves in direction  103  and  105 . 
       FIG. 7  is a perspective view of an illustrative positioner that may be used to position a DUT within a test enclosure. As shown in  FIG. 7 , positioner  42  may include support surfaces such as support surfaces  84 . Support surfaces  84  may, for example, be planar surfaces that are parallel to base surface  82  of positioner  42 . Support surfaces  84  may be used both to support a DUT as well as to precisely position a DUT in a known location along the Z axis. In the example of  FIG. 7 , support surfaces  84  include end support surface  84 A and side support surfaces  84 B,  84 C,  84 D, and  84 E. This is, however, merely illustrative. If desired, there may be one, two, three, four, or more than four support surfaces that may be used to support and position a DUT on positioner  42 . The height of support surfaces  84  relative to base  82  of positioner  42  may be known such that a DUT resting on support surfaces  84  has a known location along the Z axis. 
     In order to precisely position a DUT along the X and Y axes, positioner  42  may include guide surfaces such as guide surfaces  86 . Guide surfaces  86  may, for example, be planar surfaces that are perpendicular to support surfaces  84 . Guide surfaces  86  may be used as datums (e.g., reference points) against which a DUT is pressed as the DUT rests on support surfaces  84 . To position a DUT in a known location along the X axis, the DUT may be pressed against one or more end guide surfaces such as end guide surface  86 A. To position a DUT in a known location along the Y axis, the DUT may be pressed against one or more side guide surfaces such as guide surface  86 B and/or guide surface  86 C. Thus, a DUT resting on support surfaces  84  and in contact with guide surfaces  86  may have a known location along the X, Y, and Z axes (e.g., a known location relative to positioner  42 ). 
     The example of  FIG. 7  in which there are three guide surfaces ( 86 A,  86 B, and  86 C) on positioner  42  is merely illustrative. If desired, there may be one, two, three, four, or more than four guide surfaces that may be used to position a DUT on positioner  42 . 
     Positioner  42  may include one or more movable positioning arms such as positioning arms  60  and  142 . Positioning arms  60  and  142  may be used to press a DUT (e.g., a DUT resting on support surfaces  84 ) against guide surfaces  86 . For example, positioning arm  60  may be used to press a DUT against guide surface  86 A, whereas positioning arm  142  may be used to press a DUT against guide surfaces  86 B and  86 C. 
     Positioning arm  60  may be configured to make contact with a corner of a DUT. If, for example, DUT  10  has a shape such as that shown in  FIG. 1  (e.g., a rectangular shape having four corners), positioning arm  60  may be used to press against a corner of DUT  10  in direction  150 . Positioning arm  60  may, if desired, have a recessed surface such as recessed surface  148  that may be configured to receive a corner portion of DUT  10 . 
     The movement of positioning arms  60  and  142  may be controlled by one or more actuating members. For example, positioning arm  60  may be controlled by an associated set of actuating structures such as actuating structures  60 S, whereas positioning arm  142  may be controlled by an associated set of actuating structures such as actuating structures  142 S. 
     Actuating structures  60 S may include a first lever such as actuating lever  58  having an extending portion such as portion  136 . Actuating lever  58  and associated portion  136  may be mounted on base  82  of positioner  42  using mounting structures  158 . Mounting structures  158  may, for example, be located on opposing sides of lever  58  and may be configured to allow lever  58  and associated portion  136  to pivot about axis  124 . 
     Actuating structures  60 S may also include a second lever such as intermediary lever  138 . As shown in  FIG. 7 , intermediary lever  138  may be mechanically coupled to extending portion  136  at one end (e.g., end  138 A) and may be mechanically coupled to positioning arm  60  at an opposing end (e.g., end  138 B). At end  138 A, extending portion  136  may pass through an opening in lever  138  such as opening  160 . At end  138 B, lever  138  and the adjacent portion of positioning arm  60  may be mounted to base  82  using mounting structures  162 . Mounting structures  162  may be located on opposing sides of lever  138  and positioning arm  60 , and may be configured to allow lever  138  and positioning arm  60  to pivot about axis  126 . While lever  138  and positioning arm  60  may both be configured to pivot about axis  126 , the angle between lever  138  and positioning arm  60  (e.g., angle  164 ) may remain fixed. 
     With this type of configuration, actuating lever  58  may be used to control the movement of positioning arm  60 . When it is desired to move positioning arm  60  towards guide surface  86 A, end  58 A of lever  58  may be pressed down in direction  144 . This may in turn move extending portion  136  and attached end  138 A of lever  138  upwards in direction  146 . Because angle  164  remains fixed, moving end  138 A of lever  138  in direction  146  may in turn move end  60 A of positioning arm  60  in direction  150  (e.g., towards guide surface  86 A). 
     Actuating structures  142 S may include a first lever such as actuating lever  132 . Actuating lever  132  may be mounted on base  82  of positioner  42  using mounting structures  166 . Mounting structures  166  may, for example, be located on opposing sides of lever  132  and may be configured to allow lever  132  to pivot about axis  128 . 
     Actuating structures  142 S may also include a second lever such as intermediary lever  140 . As shown in  FIG. 7 , intermediary lever  140  may be mechanically coupled to lever  132  at one end (e.g., end  140 A) and may be mechanically coupled to positioning arm  142  at an opposing end (e.g., end  140 B). At end  140 A, lever  140  may be attached to end  132 B of lever  132 . Positioning arm  142  may be mounted on opposing end  140 B such that the angle between positioning arm  142  and lever  140  remains fixed. Lever  140  may be mounted to base  82  using mounting structures  168 . Mounting structures  168  may, for example be located on opposing sides of lever  140  and may be configured to allow lever  140  to pivot about axis  130 . 
     With this type of configuration, actuating lever  132  may be used to control the movement of positioning arm  142 . When it is desired to move positioning arm  142  towards guide surfaces  86 B and  86 C, end  132 A of lever  132  may be pressed down in direction  152 . This may in turn move end  132 B of lever  132  and attached end  140 A of lever  140  upwards in direction  154 . Because the angle between positioning arm  142  and lever  140  remains fixed, moving end  140 A of lever  140  in direction  154  may in turn move end  142 A of positioning arm  142  in direction  156  (e.g., towards guide surfaces  86 B and  86 C). 
     Positioner  42  may be mounted in a test enclosure (e.g., test enclosure  110  of  FIG. 4 ). Positioner  42  may be positioned in the test enclosure such that levers  58  and  132  are actuated when the enclosure door is in a closed position. For example, the enclosure door may include one or more protruding portions that, when the door is closed, press down on end  58 A of lever  58  (in direction  144 ) and on end  132 A of lever  132  (in direction  152 ), thereby respectively actuating positioning arms  60  and  142  to move towards guide surfaces  86 . Thus, after being placed on support surfaces  84 , a DUT may be precisely positioned within a test enclosure by closing the door of the test enclosure. 
     Positioner  42  may be provided with mounting features such as mounting features  134  that may be used to securely attach positioner  42  to a floor surface of a test enclosure. In the example of  FIG. 7 , positioner  42  is provided with a mounting feature at each of the four corners of base  82 . Mounting features  134  may include one or more holes or openings formed in base  82  and may be configured to align and mate with corresponding fastening structures in a test enclosure (e.g., mounting features  134  may be configured to receive fastening structures  80  of  FIG. 4 ). 
     Positioner  42  and the associated structures mounted on positioner  42  may be formed from any suitable material. Positioner  42  may, for example, be formed from a plastic having a low dielectric constant and a low dissipation factor. These properties may be desirable for use in testing environments such as antenna testing environments. For example, plastics having a low dielectric constant and a low dissipation factor may be used to reduce or eliminate the probability of unintentionally tuning, altering, or reflecting test signals such as radio-frequency test signals. Positioner  42  may, for example, be formed from an acetal copolymer (e.g., a polyoxymethylene plastic). Acetal copolymer is often characterized by its high strength, stiffness, and low coefficient of friction. These properties may allow positioner  42  to provide sufficient support for an electronic device without imparting unnecessary wear and tear on the electronic device. 
     If desired, different materials may be used for different structures on positioner  42 . For example, positioning arm  142  and extending portion  136  of lever  58  may be formed from a different material than the other structures on positioner  42 . If desired, positioning arm  142  and extending portion  136  may be formed from material such as polyetheretherketone. Polyetheretherketone (sometimes referred to as “PEEK” plastic) is a thermoplastic that is often characterized by its high strength and stable behavior under a wide range of conditions. This type of material is also characterized by its elasticity and shape memory. Providing positioning arm  60  and extending portion  136  with shape memory may allow these structures to be repeatedly pressed against other surfaces with little or no deformation. 
     This is, however, merely illustrative. In general, positioner  42  and the associated structures on positioner  42  may be formed using any suitable material or combination of materials. Examples of materials that may be used to form positioner  42  include polytetrafluoroethylene (PTFE), polycarbonate/acrylonitrile butadiene styrene (PC/ABS), polyamide (PA), other plastics (e.g., thermosetting polymers), and/or other suitable materials. 
       FIG. 8  is a cross-sectional side view of a portion of positioner  42  showing how positioning arm  142  may be used to press DUT  10  against guide surface  86 . As shown in  FIG. 8 , DUT  10  may be placed on support surfaces  84  of positioner  42 . By pressing down on actuating lever  132  in direction  170 , intermediary lever  140  may in turn move positioning arm  142  towards guide surface  86 , thereby pressing DUT  10  against guide surface  86 . 
     The particular configuration of positioner  42  may be customized to accommodate different types of testing environments. For example, the number and location of support surfaces  84  on positioner  42  may be customized, the number and location of guide surfaces  86  on positioner  42  may be customized, etc. Illustrative configurations of positioner  42  that may be used to precisely position a DUT along the X, Y, and Z axes are shown in  FIGS. 9-11 . In these examples, it is assumed that the location of the DUT along the Z axis is known. 
     As shown in  FIG. 9 , positioner  42  may include datums  86 X and  86 Y. Datum  86 X may have a known location along the X axis, whereas datum  86 Y may have a known location along the Y axis. A positioning arm such as positioning arm  178  may be used to press DUT  10  against datums  86 X and  86 Y (e.g., in direction  172 ). Once DUT  10  is in contact with both datums  86 X and  86 Y, the precise location of DUT  10  along the X and Y axes may be determined. In the example of  FIG. 9 , positioning arm  178  is used to press against a corner of DUT  10  in direction  172 . 
     In the example of  FIG. 10 , positioning arms  180  and  182  are located on two different sides of DUT  10 . Positioning arm  182  may be used to press DUT  10  against datum  86 X, whereas positioning arm  180  may be used to press DUT  10  against  86 Y. Once DUT  10  is in contact with both datums  86 X and  86 Y, the precise location of DUT  10  along the X and Y axes may be determined. 
     In the example of  FIG. 11 , positioning arm  184  may be located on a side of DUT  10  and may be used to press DUT  10  against datum  86 X. Positioning arm  186  may be located next to a corner of DUT  10  and may be configured to press DUT  10  against both datums  86 X and  86 Y. Once DUT  10  is in contact with both datums  86 X and  86 Y, the precise location of DUT  10  along the X and Y axes may be determined. This type of configuration is similar to that shown in  FIG. 7 . 
     In the examples of  FIGS. 9 and 11 , a positioning arm is located next to a corner of DUT  10 , leaving side  10 A of DUT  10  unobstructed. With this type of configuration, a computer-controlled loading arm or other structure may easily access DUT  10  via side  10 A. Providing access to DUT  10  in this way may allow DUT  10  to be easily placed on and easily removed from positioner  42 . 
     The exemplary configurations of positioner  42  shown in  FIGS. 9-11  are merely illustrative. Other suitable configurations of datums and positioning arms may be used to position DUT  10  in a precise location along the X, Y, and Z axes. 
       FIG. 12  is a perspective view of an illustrative test enclosure  110  showing how a plurality of fastening structures such as fastening structures  80  may be located on floor surface  74  of test enclosure  110 . Fastening structures  80  may be used to securely fasten positioner  42  to floor surface  74  of test enclosure  110 . Fastening structures  80  may include, for example, threaded standoffs, screws, brackets, other structures, etc. 
     An illustrative configuration that may be used to fasten positioner  42  to floor surface  74  of test enclosure  110  is shown in  FIG. 13 . As shown in  FIG. 13 , fastening structures  80  may include screws  80 A and threaded standoffs  80 B. Base  82  of positioner  42  may include corresponding mounting features such as mounting holes  134 . Threaded standoffs  80 B may be interposed between base  82  of positioner  42  and base  74  of test enclosure  110 . A first set of screws  80 A may pass through openings  188  in test enclosure base  74  and may be received by threaded standoffs  80 A. A second set of screws  80 A may pass through mounting holes  134  and may be received by an opposing side of threaded standoffs  80 B, thereby securely attaching base  82  of positioner  42  to base  74  of test enclosure  110 . 
     The examples shown in  FIGS. 12 and 13  are merely illustrative. If desired, any suitable method may be used to secure positioner  42  to test enclosure floor  74 . 
     DUTs  10  may be loaded into and removed from test enclosures  110  using computer-controlled loading equipment. As shown in  FIG. 14 , the computer-controlled loading equipment may include a computer-controlled loading arm such as loading arm  190 . Loading arm  190  may be configured to convey DUTs  10  between test input/output locations such as test input/output location  204 . Input/output test location  204  may, for example, be part of a storage cart having shelves on which DUTs  10  are stored before or after being tested at a given test station. Test input/output location  204  may have access features such as slots  206 . Slots  206  may allow loading arm  190  to easily pick up DUT  10  from location  204  or to drop off DUT  10  at location  204 . 
     Loading arm  190  may, if desired, be controlled by computing equipment (e.g., computing equipment  118  and/or test host  104  of  FIG. 3 ). When it is desired to test DUT  10  at a given test station, the computing equipment that controls loading arm  190  may direct loading arm  190  to pick up DUT  10  from test input location  204  and to place DUT  10  on positioner  42  within test enclosure  110  ( FIG. 4 .). When it is desired to remove DUT  10  from test enclosure  110 , the computing equipment may direct loading arm  190  to pick up DUT  10  from positioner  42  in test enclosure  110  and to place DUT  10  in an test output location. The test output location may be the same as test input location  204  or may, if desired, be a different location. 
     Loading arm  190  may be provided with suction features such as pneumatic features  208  that may be used to temporarily adhere DUT  10  to loading arm  190 . Pneumatic features  208  (sometimes referred to as pneumatic ports) may be computer-controlled and may be selectively enabled and disabled by the computing equipment. This may allow loading arm  190  to move swiftly between test input/output locations  204  and test enclosures  110  without DUT  10  sliding off loading arm  190 . 
     In the example of  FIG. 14 , pneumatic features  208  are formed on an upper surface of loading arm  190  so that loading arm  190  can hold DUT  10  from below DUT  10  (i.e., so that DUT  10  rests on top of loading arm  190 ). This is, however, merely illustrative. If desired, pneumatic features  208  may be formed on a lower surface of loading arm  190  so that loading arm  190  can hold DUT  10  from above DUT  10 . 
       FIG. 15  is a flow chart of illustrative steps involved in testing DUTs  10  in a test system such as test system  100  of  FIG. 3 . At step  302 , computing equipment (e.g., computing equipment  118 , test host  104 , or other computing equipment) may direct computer-controlled loading arm  190  to retrieve DUT  10  from a test input location and to place DUT  10  on positioner  42  within test enclosure  110 . 
     At step  304 , the computing equipment may initiate closing of the enclosure door (e.g., enclosure door  44  of  FIG. 4 ). The computing equipment may initiate closing of the enclosure door by actuating door actuator  48 . 
     At step  306 , one or more protruding portions of the enclosure door may come into contact with one or more actuating members on positioner  42  (e.g., actuating members  58  and  132  of  FIG. 7 ). When the enclosure door is in a closed position, actuating members on positioner  42  may be actuated. 
     At step  308 , each actuating member on positioner  42  may actuate an associated positioning arm on positioner  42  to press DUT  10  against an associated guide surface on positioner  42 , thereby positioning DUT  10  in a precise location along three axes (e.g., along orthogonal X, Y, and Z axes). For example, as shown in  FIG. 7 , actuating member  58  may actuate positioning arm  60  to press DUT  10  against guide surface  86 A, whereas actuating member  132  may actuating positioning arm  142  to press DUT  10  against guide surfaces  86 B and  86 C. As shown in  FIGS. 9-11 , other configurations of positioning arms may be used to press DUT  10  against one or more datums on positioner  42 . 
     At step  310 , test host  104  may direct test unit  106  to perform testing on DUT  10 . This may, for example, include over-the-air testing in which radio-frequency test signals are conveyed between test unit  106  and DUT  10  (e.g., via test antenna  114  of  FIG. 3 ). 
     Following testing of DUT  10  in the test enclosure, the computing equipment may initiate opening of the enclosure door (step  312 ). The computing equipment may initiate opening of the enclosure door by actuating door actuator  48 . 
     At step  314 , the computing equipment may direct computer-controlled loading arm  190  to remove DUT  10  from test enclosure  42  and to transfer DUT  10  to a test output location. Processing may then loop back to step  302  to test additional DUTs  10 , as indicated by path  316 . 
     Using automated equipment (e.g., computer-controlled equipment) to perform the steps of  FIG. 15  is, however, merely illustrative. If desired, a test system operator may perform the steps of loading DUT  10  into test enclosure  110  and/or closing the enclosure door prior to testing. Positioner  42  may operate to precisely position DUT  10  within the test enclosure regardless of whether or not these steps are automated or if they are performed manually. 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20120821
Publication Date: 20150908
Grant Date: 20150908
Priority Date: 20120821
Inventors: HAYLOCK JONATHAN M.
HILL ROBERT J.
PANAGAS PETER G.
Assignee: APPLE INC
CPC Classifications: [{"code": "H05K9/0069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01R1/04", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01R29/0821", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01R31/01", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01R31/01", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01R1/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/0069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01R29/0821", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01R31/01", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K9/0069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01R29/0821", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 50147448