Abstract:
The inventive fixture adapter has installed RF connectors which are connected to the fixture during the installation of the adapter in the fixture. Thus, wear on the RF connectors from opening and closing the drawer mechanism of the fixture is eliminated. The adapter is removably connected to the drawer mechanism of the fixture, and thus can quickly and reliably be changed for a different adapter. All of the customization required for a particular device can be confined to the adapter, and thus the rest of the fixture can be made generic.

Description:
RELATED APPLICATIONS 
     The present application is a divisional of Ser. No. 09/026,083, filed on Feb. 19, 1998, commonly assigned U.S. Pat. No. 6,070,478, issued Jun. 6, 2000, entitled “REMOVABLE FIXTURE ADAPTOR WITH RF CONNECTIONS,” and is related to commonly assigned U.S. Pat. No. 6,097,334, issued Aug. 1, 2000, entitled “QUICKLY REMOVABLE RF SEALED COVER FOR TEST FIXTURE,” U.S. Pat. No. 6,037,788, issued Mar. 14, 2000, entitled “DOCKING STATION FOR AUTOMATED COMMUNICATIONS TEST FIXTURE,” U.S. Pat. No. 6,047,599, issued Apr. 11, 2000, entitled “DRAWER STYLE FIXTURE WITH INTEGRAL RF DOOR,” and U.S. Pat. No. 6,067,866, issued May 30, 2000, entitled “REMOVABLE FIXTURE ADAPTER WITH PNEUMATIC ACTUATORS,” the disclosures of which are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This application relates in general to automatic testing machines, and in specific to an adapter for a test fixture of an automatic testing machine which includes RF connections on the adapter. 
     BACKGROUND OF THE INVENTION 
     An automatic testing machine (ATM) operates in a production environment to rapidly and accurately test the operation and performance of various types of devices under test (DUT), including RF communication devices. The DUTs could be a finished product or a component of a larger system. 
     The ATM is programmed to perform various tests on the DUT automatically. For example, RF signals are transmitted to a finished cellular telephone DUT to determine if the telephone activates. Other tests could include environmental tests, such as temperature or vibration tests. 
     Depending upon the nature and number of the tests being performed, the testing may last from a couple of milliseconds to several minutes. The information from the testing is compared with expected test results. If there is some defect so that the DUT falls below specifications, the ATM will designate the DUT as failed, either by marking the DUT, placing the DUT in a failure area, or indicating the failure to an operator. 
     The ATM is then loaded with the next DUT, either manually or automatically, and the testing procedure is repeated for this DUT. This test information can be used to evaluate the fabrication process for possible changes, as well as to perform failure analysis on individual failed devices. 
     Typically, each ATM is designed to perform a specific class of tests on the DUT, and are not able to perform other classes of tests. For example, a vibration ATM may not be able to perform electrical signal tests. However, different types of DUTs may require the same tests to be performed. For example, all types of microcomputer chips are tested for electronic performance characteristics, but different chips will have different locations for power, inputs and outputs. ATMs are made flexible by the use of test fixtures. The test fixture provides an interface between the device under test DUT and the ATM. Thus, a single ATM can perform tests on different types of devices when connected via different fixtures. 
     Fixtures typically have a drawer mechanism, which opens up and allows the DUT to be placed inside the fixture. The fixture may have an RF cable that fixedly mounted within the fixture, and has a length of cable which is connected to the drawer mechanism. The cable terminates at a connector which is pneumatically engaged on the telephone. Some fixtures have RF probe connector mounted inside the fixture which makes contact with an antenna element on the DUT. Thus, contact is not made until the drawer is closed. Thus, RF connections, pneumatic actuators, and their air supplies, are hardwired or constructed directly onto the drawer mechanism. The hardwired aspects makes fixtures extremely difficult to reconfigure, because all the of the fixture elements are integrally built into the fixture. 
     Moreover, fixtures tend to be large and bulky. Also, they have numerous connections to the ATM for the required resources to allow testing, e.g. power, electronic signals, RF signals, and pneumatic air pressure. Thus changing fixtures is time consuming, as each individual connection to the ATM must be separated, the current fixture removed, and then the new fixture installed. During the replacement process, the production line is shut down, which results in lost production time. If the fixture needs to be repaired, then this process must be undertaken, and the lost production time is unavoidable. However, if the fixture is to be changed merely to accommodate a different DUT, then the lost production time can be mitigated by using an adapter. An adapter is a DUT holder that is coupled to the fixture on the drawer mechanism. The adapter is customized to hold the specific type of DUT. If a different DUT needs to be tested then the adapter in the fixture is swapped for the proper adapter. 
     However, the adapter does not have any continuous or semi-permanent RF connections, as RF connection is only made when the drawer mechanism is closed. The lack of continuous connection by itself is not a problem, since RF testing cannot begin until the RF sealed drawer is closed. The problem is the wear on the connectors from many cycles of the drawer being opened and closed. Typically, one end of a connector is located at the back of the adapter, and the other end of the connector is located inside of the fixture mount, thus, when the drawer is closed, the connection would be made. The RF connection degrades based on the number of cycles, and the degradation is very significant. One form of degradation is where the plating on the mating parts wears from continual cycles of making and breaking contact. Another form occurs where the connectors have a soft plastic core used to form a dielectric layer between the two conductors of the coaxial cable. The plastic core would crack or degrade from the flexings caused by cycles of making and breaking contact. Consequently, the connectors do not last very long, and significant production downtime is incurred for replacing the connectors. 
     Therefore, there is a need in the art for a system and method that allows for the rapid and reliable conversion of an ATM to test a different DUT, and at the same time reduce the wear on RF connections from opening and closing the drawer mechanism of the fixture in a production environment. 
     SUMMARY OF THE INVENTION 
     These and other objects, features and technical advantages are achieved by a system and method that uses a fixture adapter that has RF connectors installed on the adapter. Connections from the fixtures to the RF connectors from the fixture are made during installation of the adapter in the fixture. 
     The adapter is removable from the drawer style fixture, and thus can quickly and reliably be changed for a different adapter for another DUT or to perform maintenance on the current adapter. The adapter allows all of the customization required for a certain product or DUT to be confined to one removable piece which can be quickly changed for a different DUT. This allows the rest of the fixture to be generic. Moreover, the adapter can have more custom features than a prior art fixture could have, since prior art fixtures were built to be more generic than the inventive adapter. 
     Since the RF connections are made to the adapter at the time of the installation of the adaptor, no wear occurs on the RF connectors from cycles of opening and closing the fixture drawer. The only time the connection is made is during installation of the adapter, and the only time connection is broken is during removal of the adapter. 
     A technical advantage of the present invention is reduction in downtime and errors caused by changing fixtures to test a different device. 
     Another technical advantage of the present invention is the reduction in cycle wear on RF connectors. 
     A further technical advantage of the present invention is that all customization required for a particular DUT is located on the adapter. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 depicts the inventive adapter mechanism; 
     FIG. 2 depicts a drawer type fixture for an automatic testing machine; and 
     FIG. 3 depicts the adapter of FIG. 1 in the drawer fixture of FIG.  2 . 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 depicts the inventive adapter mechanism  10 . Adapter  10  includes base plate  11  upon which other elements are secured. RF connectors  12  are located in the rear of the adapter  10 . Each of connectors  12  comprises double male connectors, one on top of plate  11  and one underneath plate  11 . The connections underneath couple via quick disconnects to female connectors located on fixture  20  of FIG. 2, and the connections on top couple with RF emission points or contact points. Alternatively, female connectors can be located under plate  11  which couple to male connectors located on fixture  20 . With either arrangement, the connection between adapter  10  and fixture  20  occurs when the adapter is installed. In other words, as the adapted is pushed into the fixture, connectors  12  couple with complementary connectors  22 . The RF lines (not shown for reasons of simplicity) from the connectors  12  are routed down through hole  16  to the various RF contact points on adapter  10 . Thus, the lines do not interfere with the loading and unloading process of the DUTs and the operations of the actuators during testing. 
     Adapter  10  has several RF contact points. The number and location of the RF connecters  12  and contact points is by way of example only, as the precise number and placement depends upon the testing requirements of the particular DUT and ATM. On the adapter depicted in FIG. 1, there are two RF contact points. The first point  14  is to an over-the-air antenna, which transmits the RF signal through the air. The second point  15  is a direct connection made with the DUT, in this case, a cellular telephone. Note that connection  15  is vertically moved by a pneumatically actuated slide. Typically, direct RF connections to the DUT are more accurate than the over-the-air RF connections. The RF cables from connections  12 , which pass though hole  16  to travel beneath plate  11  would emerge through hole  26  and attach at connection points  14  and  15 . Connection wear is prevented because the connection to connectors  12  is not made and broken with every cycle. However, some wear will occur at connection point  15 . However, the prior art would also incur corresponding wear at a similar location, in addition to the connection wear from opening and closing the drawer. 
     Adapter  10  is coupled to fixture  20  via holes  18 . Holes  18  are hardened steel bushing, each bushing receives an alignment pin  23  located on drawer  21  of fixture  20 . Adapter  10  also includes holes  19  into which 1/4 turn fasteners are placed which secure adapter  10  to fixture drawer  21 . Other types of fasteners could be used. Thus, to change adapters, the fasteners are removed and the adapter is pulled out. This simultaneously separates connectors  12  from receivers  22 . The replacement adapter is then aligned in the drawer, via the alignment pins  23  and bushing  18 , and installed. This simultaneously connects the connectors  12  and the receivers  22 . The fasteners are then installed to secure the adapter. FIG. 3 depicts adapter  10  connected to fixture  20 . 
     FIG. 2 depicts fixture  20  with drawer  21 . Fixture  20  includes RF receivers  22 . RF lines are connected between receivers  22  and the fixture  20 . Fixture  20  also includes alignment pins  23  which are used to align adapter  10  during loading of the adapter. Fixture  20  uses cable router  24  to bundle the RF lines which lead to receivers  22 . 
     Adapter  10  has portion  17  used for electrical signal connectors (not shown). These connectors are spring loaded pins that engage straight down onto a printed circuit board  25  having an array of test pads, which would be located on fixture  20 . The electrical connection would be made (or broken) simultaneously with the installation (or removal) of the adapter. The circuit board would provide data signals, control signals, and other types of electrical signals necessary for the testing of the DUT. The adapter has nest area  13  to secure the DUT (not shown). Although not shown in the adapter of FIG. 1, pneumatic actuators can be used in nest area  13  to capture and hold the DUT. The adaptor also includes pneumatically actuated slides, which move both vertically and horizontally to engage the DUT for testing. The adapter also may hold various transducers (not shown) to communicate with or measure the DUT, including but not limited to infrared communications, vibrations sensors, acoustic microphones, DUT presence sensors, color detectors, RF couplers, etc. 
     During operation of the ATM, a DUT is loaded into adapter  10  of fixture  20 . Completion of loading is communicated to the ATM via the loading robot. Once the drawer is closed, testing begins, typically with calibration of the DUT and sensors. Other testing such as operational testing or RF testing is performed with the drawer closed. Once testing is completed the drawer is opened and the next device is tested. 
     Note that the testing of the DUT may require electrical signals and/or chemicals, in addition or instead of RF signals. Thus, the connectors and lines, as described above with regards to RF, would allow the passage of either electricity or chemicals from the fixture to the there required use or testing points through the adapter. Chemicals may require a return line for unused chemicals or chemical bi-products from testing. Electrical signals would either require a return line or having the adapter grounded to the fixture, to allow the flow of electrical current. Return lines would follow the same path through the adapter as the lines bringing resource. Note that various combinations of the testing resources may be required to perform tests on the DUT held on the adapter. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.