Abstract:
A method includes; generating, via a testing signal source, a test transmission signal; receiving the test transmission signal at an input port of a socket device having the input port, an input coupler, a divider, a combiner, an output coupler and an output port; providing, via the input coupler, an input signal based on the test transmission signal; providing, via the divider, portions of the input signal to each of respective inputs of in receivers of a transceiver having n transmitters and the m receivers; combining, via the combiner, signals provided at the respective outputs of the n transmitters into a combined output signal; providing a coupled output signal to the input coupler; providing a measured output signal to the output port; providing, via the output port, the measured output signal to a receiving signal measuring device; and testing, via the receiving signal measuring device, the measured output signal.

Description:
[0001]    The present application claims priority from: U.S. Provisional Application No. 62/160,444 filed May 12, 2015, the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The present invention generally deals with testing transceivers. Conventional systems for testing transceivers will now be discussed with reference to  FIGS. 1-2E . 
         [0003]      FIG. 1  illustrates a conventional system  100  for testing a transceiver  104 . 
         [0004]    As illustrated in the figure, system  100  includes a signal generator  102 , transceiver  104  and a signal tester  106 . Transceiver  104  includes a receiver  108  and a transmitter  110 . System  100  additionally includes communication channels  112 ,  114 ,  116 ,  118  and  120 . 
         [0005]    Signal generator  102  is in communication with receiver  108  by way of communication channel  112 . Further, signal generator  102  is in communication with signal tester  106  by way of communication channel  120 . Signal tester  106  is in communication with receiver  108  by way of communication channel  114 . Further, signal tester  106  is in communication with transmitter  110  by way of communication channels  116  and  118 . 
         [0006]    Signal generator  102  may be any system or device that is able to generate a known signal to be transmitted by a receiver to test the transceiver. 
         [0007]    Transceiver  104  may be any system or device that is able to transmit a signal and receive a signal. In cases wherein the transmitted signal is the received signal, transceiver is a repeater. 
         [0008]    Signal tester  106  may be any system or device that is able to receive to known signal and determine if the received signal is correct and within a certain threshold of a predetermined acceptable signal. 
         [0009]    Receiver  108  may be any system or device part of a transceiver that is able to receive or accept a signal. 
         [0010]    Transmitter  110  may be any system or device part of the transceiver that is able to transmit a signal. 
         [0011]    Transceiver  104  is tested with signal generator  102  and signal tester  106 . Receiver  108  and transmitter  110  are tested separately. 
         [0012]    To test receiver  108 , signal generator  102  provides known test signal  122  to receiver  108  by way of communication channel  112 . 
         [0013]    Test signal  122  is a predetermined signal having predetermined parameters, such as amplitude, frequency and/or phase. Receiver  108  will have a predetermined transfer function. As such signal  138  that is output from receiver  108  should have a known correspondence to test signal  122 . If signal  138  deviates from the known correspondence, then receiver  108  is not working properly. 
         [0014]    Signal tester  106  determines whether receiver  108  is working properly. In particular, signal generator  102  provides signal  126  to signal tester  106 . Signal  126  informs signal tester  106  of signal  122 . In some cases signal  126  may be signal  122 . Signal tester  106  has knowledge of the transfer function of receiver  108 , such that signal tester  106  is able to determine the expected output signal from receiver  108  based on signal  122 . Accordingly, signal tester  106  can compare signal  138  with the expected output signal from receiver  108  to determine whether receiver  108  is operating within acceptable parameters. 
         [0015]    In some cases, if receiver  108  is not working within acceptable parameters, then transceiver  100  is discarded. In some cases, if receiver  108  is adjustable, signal tester  106  may provide an adjusting signal  128  to receiver  108  via communication channel  114 . In this manner the operation of receiver  108  is adjusted. Receiver  108  may then be tested again, and adjusted if needed. This process continues until receiver  108  is operating within acceptable parameters or until a determination is made to discard transceiver  100 . 
         [0016]    To test transmitter  110 , signal tester  106  provides a known test signal  136  to transmitter  110  by way of communication channel  132 . 
         [0017]    Test signal  136  is a signal having data that informs transmitter  110  to generate a specific signal. Transmitter  110  will have a predetermined transfer function. Signal  124  that is output from transmitter  110  should have a known correspondence to test signal  136 . If signal  124  deviates from the known correspondence, then transmitter  108  is not working properly. 
         [0018]    Signal tester  106  determines whether transmitter  110  is working properly. Signal tester  106  has knowledge of the transfer function of transmitter  110 , such that signal tester  106  is able to determine the expected output signal from transmitter  110  based on signal  124 . Accordingly, signal tester  106  can compare signal  124  with the expected output signal from transmitter  110  to determine whether transmitter  110  is operating within acceptable parameters. 
         [0019]    In some cases, if transmitter  110  is not working within acceptable parameters, then transceiver  100  is discarded. In some cases, if transmitter  110  is adjustable, signal tester  106  may provide an adjusting signal  130  to transmitter  110  via communication channel  116 . In this manner the operation of transmitter  110  is adjusted. Transmitter  110  may then be tested again, and adjusted if needed. This process continues until transmitter  110  is operating within acceptable parameters or until a determination is made to discard transceiver  100 . 
         [0020]    Another method of testing transceiver  100  deals with a loop hack. In a loop back test, a signal transmitted from transmitter  110  is received by receiver  108 . A loop back test is much faster than the external test discussed above. However, there are inherent problems with a loop back test. For example, there is a possibility transmitter  110  is operating in an equal yet opposite improper amount than that of receiver  108  such that the overall tested loop back seems proper. 
         [0021]    For example, suppose that transmitter  110  transmits a signal at an amplitude that is −3 dB of the required transmission amplitude and that has a phase delay of +5° of the required transmission phase. Further, suppose that receiver  108  outputs a signal at an amplitude that is +3 dB of the expected receiving amplitude and that has a phase delay of −5° of the required receiving phase. In such a case, output signal from receiver  108  would seem to accurately correspond to the input signal of transmitter  110 . However, in actuality, each of receiver  108  and transmitter  110  were working improperly. 
         [0022]    System  100  is drawn to a single receiver and a single transmitter. However, some conventional transceivers include a receiver array and a transmitter array. For example, radar array transceivers used in the automobile industry have an array of radar transmitters and an array of radar receivers. For these types of radar transceivers, all of the receivers in the receiver array and transmitters in the transmitter array have to be tested. This will be described with additional reference to  FIGS. 2A-E . 
         [0023]      FIGS. 2A-E  illustrate a conventional system  200  for testing a radar transceiver  202 . 
         [0024]    As illustrated in the figures, system  200  includes signal generator  102 , radar transceiver  202  and signal tester  106 . Radar transceiver  202  includes a receiver array  204  and a transmitter array  206 . Receiver array  204  includes receivers  208 ,  210 ,  212  and  214 . Transmitter array  206  includes transmitters  216 ,  218  and  220 . System  200  additionally includes communication channels  112 ,  114 ,  116 ,  118  and  120 . 
         [0025]    Radar transceiver  202  may be any system or device that is able to send and receive a plurality of signals to/from the signal generator and the signal tester. 
         [0026]    Receiver array  204  may be any system of device that includes a plurality of m receivers, wherein m is an integer greater than 1. In this example, receiver array  204  includes four receivers. 
         [0027]    Transmitter array  206  may be any system or device that includes a plurality of n transmitters, wherein n is an integer greater than 1. In this example, transmitter array  206  includes three transmitters. In some cases, n may be equal to m. 
         [0028]    Radar transceiver  202  is a frequency chirp architecture, which is the most popular of the automotive CW radars. In frequency-chirped radars, the frequency of the radar signal is varied according to a pre-determined pattern. The most widely used patterns are (a) frequency-stepped, in which frequency is changed by a step in each time period and (b) Linear Frequency Modulation (LFMCW), often referred to simply as FMCW, in which transmit frequency is changed continuously within each time period. This varying frequency essentially widens the bandwidth of the radar signal, which is equivalent to narrowing the signal in the time-domain. An FMCW radar can simultaneously estimate both the velocity and range of multiple objects. 
         [0029]    A radar beam includes a continuous series of transmitted frequency modulated “chirps”, each chirp being a short period of radar carrier transmission ramping in frequency from, for example, 77 GHz to 81 GHz. For any transmitted chirp, a plurality of reflected waves will each arrive back at radar transceiver  202  at a different time, with a different Doppler and at a different arrival angle. 
         [0030]    An object&#39;s distance, velocity, and angle within the beam can be ascertained by analyzing the properties of their reflected waves. For chirped radar, both the velocity and distance of an object from radar transceiver  202  can be ascertained by analyzing the spectrum of the received signals. Since radar transceiver  202  has a plurality of receivers in the form of an antenna array, the angle of arrival of the reflected waves can be ascertained by analyzing the reflected wave reception across the antennas comprising the array. 
         [0031]    To verify the accuracy of radar transceiver  202 , each of receivers  208 ,  210 ,  212  and  214  in receiver array  204  and each of transmitters  216 ,  218  and  220  in transmitter array  206  must be calibrated or tested. 
         [0032]    Such testing will now be described in greater detail with reference to  FIGS. 2A-E . To test receiver  208 , receiver  208  is tested against all transmitter within transmitter array  206 . This will be described with reference to  FIGS. 2A-D . For purposes of discussion, start with a test of receiver  208  using transmitter  220  of transmitter array  206 . This will be described with reference to  FIG. 2A . 
         [0033]      FIG. 2A  illustrates conventional system  200  for testing radar transceiver  202 , wherein receiver  208  and transmitter  220  are being tested at a time t 1 . As such, signal generator  102  is connected to receiver  208  of receiver array  204  via communication channel  112 , whereas signal tester  106  is connected to transmitter  220  of transmitter array  206  via communication channel  116  and communication channel  118 . Further, signal tester  106  is connected to receiver  208  via communication channel  114 . Still further, signal tester  106  is connected to all the receivers within receiver array  204  via communication channel  134 . Finally, signal tester  106  is additionally connected to all the transmitters within transmitter array  206  via communication channel  132 . 
         [0034]    At time t 1 , to test receiver  208 , signal generator  102  provides a known test signal  122  to receiver  208  by way of communication channel  112 . 
         [0035]    Test signal  122  is a predetermined signal having predetermined parameters, such as amplitude, frequency and/or phase. Receiver  208  will have a predetermined transfer function. As such, signal  138  that is output from receiver  208  should have a known correspondence to test signal  122 . If signal  138  deviates from the known correspondence, then receiver  208  is not working properly. 
         [0036]    Signal tester  106  determines whether receiver  308  is working properly. In particular, signal generator  102  provides signal  126  to signal tester  106 . Signal  126  informs signal tester  106  of signal  122 . In some cases, signal  126  may be signal  122 . Signal tester  106  has knowledge of the transfer function of receiver  208 , such that signal tester  106  is able to determine the expected output signal from receiver  208  based on signal  122 . Accordingly, signal tester  106  can compare signal  138  with the expected output signal from receiver  208  to determine whether receiver  208  is operating within acceptable parameters. 
         [0037]    In some cases, if receiver  208  is not working within acceptable parameters, then transceiver  200  is discarded. In some cases, if receiver  208  is adjustable, signal tester  106  may provide an adjusting signal  128  to receiver  208  via communication channel  114 . In this manner the operation of receiver  208  is adjusted. Receiver  208  may then be tested again, and adjusted if needed. This process continues until receiver  208  is operating within acceptable parameters or until a determination is made to discard transceiver  200 . 
         [0038]    To test transmitter  220 , signal tester  106  provides a known test signal  136  to transmitter  110  by way of communication channel  132 . 
         [0039]    Test signal  136  is a signal having data that informs transmitter  220  to generate a specific signal. Transmitter  220  will have a predetermined transfer function. Signal  124  that is output from transmitter  220  should have a known correspondence to test signal  136 . If signal  124  deviates from the known correspondence, then transmitter  220  is not working properly. 
         [0040]    Signal tester  106  determines whether transmitter  220  is working properly. Signal tester  106  has knowledge of the transfer function of transmitter  220 , such that signal tester  106  is able to determine the expected output signal from transmitter  220  based on signal  124 . Accordingly, signal tester  106  can compare signal  124  with the expected output signal from transmitter  220  to determine whether transmitter  220  is operating within acceptable parameters. 
         [0041]    In some cases, if transmitter  220  is not working within acceptable parameters, then transceiver  200  is discarded. In some cases, if transmitter  220  is adjustable, signal tester  106  may provide an adjusting signal  130  to transmitter  220  via communication channel  116 . In this manner the operation of transmitter  220  is adjusted. Transmitter  220  may then be tested again, and adjusted if needed. This process continues until transmitter  220  is operating within acceptable parameters or until a determination is made to discard transceiver  200 . 
         [0042]    After receiver  208  is tested, then receiver  210  may be tested in the same manner. This will be described in greater detail with reference to  FIG. 2B .  FIG. 2B  illustrates conventional system  200  for testing radar transceiver  202 , wherein receiver  210  and transmitter  220  are being tested at a time t 2 . 
         [0043]    In operation, first of all, receiver  208  must be disconnected to communication channels  112  and  114 . Then receiver  210  is connected to communication channels  112  and  114 . 
         [0044]    To test receiver  210 , signal generator  102  provides a known test signal  222  to receiver  210  by way of communication channel  112 . 
         [0045]    Test signal  222  is a predetermined signal having predetermined parameters, such as amplitude, frequency and/or phase. Receiver  210  will have a predetermined transfer function. As such, signal  138  that is output from receiver  210  should have a known correspondence to test signal  222 . If signal  138  deviates from the known correspondence, then receiver  210  is not working properly. 
         [0046]    Signal tester  106  determines whether receiver  210  is working properly. In particular, signal generator  102  provides signal  126  to signal tester  106 . Signal  126  informs signal tester  106  of signal  222 . In some cases, signal  126  may be signal  222 . Signal tester  106  has knowledge of the transfer function of receives  210 , such that signal tester  106  is able to determine the expected output signal from receiver  210  based on signal  222 . Accordingly, signal tester  106  can compare signal  138  with the expected output signal from receiver  210  to determine whether receiver  210  is operating within acceptable parameters. 
         [0047]    In some cases, if receiver  210  is not working within acceptable parameters, then transceiver  200  is discarded. In some cases, if receiver  210  is adjustable, signal tester  106  may provide an adjusting signal  226  to receiver  210  via communication channel  114 . In this manner the operation of receiver  210  is adjusted. Receiver  210  may then be tested again, and adjusted if needed. This process continues until receiver  210  is operating within acceptable parameters or until a determination is made to discard transceiver  200 . 
         [0048]    To test transmitter  220 , signal tester  106  provides a known test signal  136  to transmitter  110  by way of communication channel  132 . 
         [0049]    Test signal  136  is a signal having data that informs transmitter  220  to generate a specific signal. Transmitter  220  will have a predetermined transfer function. Signal  224  that is output from transmitter  220  should have a known correspondence to test signal  136 . If signal  224  deviates from the known correspondence, then transmitter  220  is not working properly. 
         [0050]    Signal tester  106  determines whether transmitter  220  is working properly. Signal tester  106  has knowledge of the transfer function of transmitter  220 , such that signal tester  106  is able to determine the expected output signal from transmitter  220  based on signal  224 . Accordingly, signal tester  106  can compare signal  224  with the expected output signal from transmitter  220  to determine whether transmitter  220  is operating within acceptable parameters. 
         [0051]    In some cases, if transmitter  220  is not working within acceptable parameters, then transceiver  200  is discarded. In some cases, if transmitter  220  is adjustable, signal tester  106  may provide an adjusting signal  228  to transmitter  220  via communication channel  116 . In this manner the operation of transmitter  220  is adjusted. Transmitter  220  may then be tested again, and adjusted if needed. This process continues until transmitter  220  is operating within acceptable parameters or until a determination is made to discard transceiver  200 . 
         [0052]    After receiver  210  is tested, then receiver  212  may be tested in the same manner.  FIG. 2C  illustrates conventional system  200  for testing radar transceiver  202 , wherein receiver  212  and transmitter  220  are being tested at a time t 3 . 
         [0053]    In operation, first of all, receiver  210  must be disconnected to communication channels  112  and  114 . Then receiver  212  is connected to communication channels  112  and  114 . 
         [0054]    The testing is similar to that discussed above with reference to  FIGS. 2A-B . However, when testing receiver  212  signal tester  106  compares signal  138  with a test signal  230 , wherein receiver  212  may be adjusted via adjusting signal  234 . Further, when testing transmitter  220 , signal tester  106  compares signal  232  with test signal  136 , wherein transmitter  220  may be adjusted via adjusting signal  236 . 
         [0055]    After receiver  212  is tested, then receiver  214  may be tested in the same manner.  FIG. 2D  illustrates conventional system  200  for testing radar transceiver  202 , wherein receiver  214  and transmitter  220  are being tested at a time t 4 . 
         [0056]    In operation, first of all, receiver  212  must be disconnected to communication channels  112  and  114 . Then receiver  214  is connected to communication channels  112  and  114 . 
         [0057]    The testing is similar to that discussed above with reference to  FIGS. 2A-C . However, when testing receiver  214  signal tester  106  compares signal  138  with a test signal  238 , wherein receiver  214  may be adjusted via adjusting signal  242 . Further, when testing transmitter  220 , signal tester  106  compares signal  240  with test signal  136 , wherein transmitter  220  may be adjusted via adjusting signal  244 . 
         [0058]    Now that transmitter  220  and all receivers within receiver array  204  have been tested, the remaining transmitters within transmitter array  206  and the same receivers within receiver array  204  additionally need to be tested. For example,  FIG. 2E  shows transmitter  218  and receiver  208  being tested at a time t 5 . 
         [0059]    In operation, first of all, receiver  208  must be again connected to communication channels  112  and  114 . Further, transmitter  220  must be disconnected to communication channels  116  and  118 . Then transmitter  218  is connected to communication channels  116  and  118 . 
         [0060]    The testing is similar to that discussed above with reference to  FIG. 2A . However, when testing transmitter  208  signal tester  106  compares signal  138  with a test signal  246 , wherein receiver  208  may be adjusted via adjusting signal  250 . Further, when testing transmitter  218 , signal tester  106  compares signal  248  with test signal  136 , wherein transmitter  218  may be adjusted via adjusting signal  252 . 
         [0061]    The remaining receivers within receiver array  204  and transmitter  218  are then tested, commensurate with the multiple connecting/disconnecting when required. Then transmitter  216  and the same receivers within receiver array  204  are then tested in a similar manner. 
         [0062]    Transceiver  200  can also be tested in a loop back method. Again however, inherent problems with a loop back test as discussed above with reference to transceiver  100  would be present in the test of transceiver  200  also. Further, the multiple connection/disconnections would still need to be performed to test all transmitters and receivers in transceiver  200 . 
         [0063]    Accordingly, for at least the foregoing reasons there exists a need for a system and method to efficiently and accurately test a transceiver having a transmitter array and receiver array. 
       SUMMARY 
       [0064]    The present invention provides a system and method to efficiently and accurately test a transceiver having a transmitter array and receiver array. 
         [0065]    An aspect of the present invention is drawn to a system and method for testing a transceiver. The method includes: generating, via a testing signal source, a test transmission signal; receiving the test transmission signal at an input port of a socket device having the input port, an input coupler, a divider, a combiner, an output coupler and an output port; providing, via the input coupler, an input signal based on the test transmission signal; providing, via the divider, portions of the input signal to each of respective inputs of m receivers of a transceiver having n transmitters and the m receivers, n being an integer greater than one and m being an integer greater than one, each of the n transmitters having a respective transmitter input and a respective transmitter output, each of the m receivers having the respective receiver input and a respective receiver output; combining, via the combiner, signals provided at the respective outputs of the n transmitters into a combined output signal; providing, via the output coupler and based on the combined output signal, a coupled output signal to the input coupler; providing, via the output coupler and based on the combined output signal and the coupled output signal, a measured output signal to the output port; providing, via the output port, the measured output signal to a receiving signal measuring device; and testing, via the receiving signal measuring device, the measured output signal. 
         [0066]    Additional advantages and novel features of the invention are set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
     
    
     
       BRIEF SUMMARY OF THE DRAWINGS 
         [0067]    The accompanying drawings, which are incorporated in and form a part of the specification, illustrate an exemplary embodiment of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings: 
           [0068]      FIG. 1  illustrates a conventional system for testing a transceiver; 
           [0069]      FIG. 2A  illustrates a conventional system for testing a radar transceiver at a time t 1 ; 
           [0070]      FIG. 2B  illustrates conventional system for testing a radar transceiver of  FIG. 2A , but at a time t 2 ; 
           [0071]      FIG. 2C  illustrates conventional system for testing a radar transceiver of  FIG. 2A , but at a time t 3 ; 
           [0072]      FIG. 2D  illustrates conventional system for testing a radar transceiver of  FIG. 2A , but at a time t 4 ; 
           [0073]      FIG. 2E  illustrates conventional system for testing a radar transceiver of  FIG. 2A , but at a time t 5 ; 
           [0074]      FIG. 3A  illustrates a system for testing a transceiver in an external testing mode in accordance with aspects of the present invention; 
           [0075]      FIG. 3B  illustrates a system for testing a transceiver in a loopback testing mode in accordance with aspects of the present invention; and 
           [0076]      FIG. 4  illustrates a system for testing a plurality of transceivers in accordance with aspects of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0077]    Aspects of the present invention are drawn to a system and method for testing a transceiver having a receiver array and a transmitter array. 
         [0078]    Aspects of the present invention include a socket device, which is disposed between a transmitter array of a transceiver and a receiver array of the transceiver. The socket device includes a power combiner, a power divider, an input coupler, a loopback line and output coupler. The socket device enables the transmitter array and the receiver array each be easily tested by way of an external testing mode or by way of a loopback mode. 
         [0079]    In the external testing mode, the input coupler connects an external signal generator to the power divider and receiver array and the output coupler connects the power combiner and transmitter array to an external signal tester. In an example embodiment, the external test equipment provides a test signal to the receiver array. The power divider splits the test transmission signal such that it is received by all the receivers of the receiver array. Further, the power combiner combines the outputs of the transmitters of the transmitter array. The signal transmitted from the transmitter array then travels through the output coupler to he measured by the external signal tester. 
         [0080]    In the loopback testing mode, signals generated by the transmitter array are used to test the receiver array. In the loopback testing mode, an output from the transmitter array is provided to the output coupler. The output coupler transmits the signal from the transmitter array to the input coupler by way of the loopback line. The input coupler then provides the signal from the loopback line to the power divider and receiver array. 
         [0081]    Example embodiments in accordance with aspects of the present invention will now he described with reference to  FIGS. 3A-B . 
         [0082]      FIGS. 3A-B  illustrate a system  300  for testing a transceiver  302  in accordance with aspects of the present invention. 
         [0083]    As illustrated in the figures, system  300  includes signal generator  102 , signal tester  106 , a controller  304 , a signal tester  306 , a signal generator  308 , a socket device  310 , a socket device  312 , communication channel  112 , communication channel  118 , communication channel  120 , a communication channel  314 , communication channel  316 , a communication channel  318 , a communication channel  320 , a communication channel  322 , a communication channel  324  and a communication channel  326 . 
         [0084]    Transceiver  302  includes receiver array  204 , transmitter array  206 , and a transceiver portion  328 . 
         [0085]    Socket device  310  includes an input coupler  330 , a power divider  332 , a power combiner  334 , an output coupler  336  and a loopback line  338 . Socket device  312  additionally includes an input coupler (not shown), an output coupler (not shown) and a loopback line (not shown). 
         [0086]    Transceiver portion  328  includes a transmitter  340  and a receiver  342 . Transceiver  302  may be any system or device that is able to send and receive a plurality of signals to/from the signal generator and the signal tester. 
         [0087]    Controller  304  may be any system or device that is able to selectively control transmitters  216 ,  218  and  220  of transmitter array  206 . 
         [0088]    Signal generator  308  may be any system or device that is able to generate a known signal to be transmitted by a receiver for the testing of a transceiver, to assure the transceiver operates correctly. 
         [0089]    Signal tester  306  may be any system or device that is able to receive a known signal and determine if the received signal is correct and within a certain threshold of a predetermined acceptable signal. 
         [0090]      FIG. 3A  illustrates the external testing mode of system  300  in accordance with aspects of the present invention. 
         [0091]    As illustrated in  FIG. 3A  signal generator  102  provides a known test transmission signal  344  to receiver array  204  by way of communication channel  112 , and signal tester  106  tests a measured output signal  346  from transmitter array  206  by way of communication channel  118 . 
         [0092]    As shown in the figure, signal generator  102  tests receiver array  204 , whereas signal tester  106  tests transmitter array  206 . During the external testing mode, test transmission signal  344  is sent from signal generator  102  and passes through input coupler  330 . 
         [0093]    In the external testing mode, input coupler  330  couples test transmission signal  344  to generate input signal  348 . Input coupler  330  has a predetermined transfer function, such that input signal  348  will have a predetermined functional relationship to test transmission signal  344  with respects to predetermined parameters, non-limiting examples of which include amplitude, phase, frequency and combinations thereof. In some example embodiments, the functional relationship to test transmission signal  344  can be determined by calibration procedures. 
         [0094]    Input signal  348  is then provided to receiver array  204  by way of power divider  332 . Power divider  332  splits input signal  348  to all receivers of receiver array  204 . In some embodiments, power divider  332  equally splits input signal  348  to all receivers of receiver array  204 . In other embodiments, power divider  332  unevenly splits signal  348  in accordance with predetermined parameters. For purposes of discussion therein, in an example embodiment, power divider  332  equally splits input signal  348  to all receivers of receiver array  204 . 
         [0095]    Each receiver in receiver array  204  will then output a received signal based on the portion of input signal  348 , for which it receives. Each receiver will have a predetermined transfer function, such that the output signal will have a predetermined functional relationship to the input signal with respects to predetermined parameters, non-limiting examples of which include amplitude, phase, frequency and combinations thereof. 
         [0096]    These output signals from the individual receivers are transmitted to controller  304  as a feedback signal  350  by way of communication channel  318 , Feedback signal  350  provides information to controller  304  to assure the receivers on receiver array  204  are operating correctly based on test transmission signal  344  generated from signal generator  102 . In some example embodiments, receiver array  204  outputs are internally verified to function and sent to controller  304 . Further, in some example embodiments, output signals from receiver array  204  can be sent to signal tester  106  as an analog signal to verify its quality. 
         [0097]    Signal generator  102  sends signal  352  to signal tester  106  by way of communication channel  120 . Signal  352  includes information to inform signal tester  106  of test transmission signal  344  as provided to receiver array  204 . 
         [0098]    Controller  304  also sends a signal  354  to signal generator  102  via communication channel  316 . Signal  354  instructs signal generator  102  to transmit test transmission signal  344  to receiver array  204 . 
         [0099]    During the test sequence, signal  354  instructs signal generator  102  to transmit signal  344  for testing receivers  208 ,  210 ,  212  and  214  of receiver array  204 . The transfer function of each of input coupler  330  and power coupler  332  are known, such that the signals received by each are receivers  208 ,  210 ,  212  and  214  are known. Further, the transfer function of each of receivers  208 ,  210 ,  212  and  214  are anticipated. 
         [0100]    The expected output signal from each of receivers  208 ,  210 ,  212  and  214  that correspond to signal  354  is based on the known transfer function of each of input coupler  330  and power divider  332  and the anticipated transfer function of each of receivers  208 ,  210 ,  212  and  214 . In an example embodiment, these expected output signals from receivers  208 ,  210 ,  212  and  214  are stored in controller  304 . 
         [0101]    In this manner, the actual output signal from each of receivers  208 ,  210 ,  212  and  214  are provided to controller  304  as feedback signal  350 . In some embodiments, feedback signal  350  comprises a serial composition of an output signal from each of receivers  208 ,  210 ,  212  and  214 . In some embodiments, feedback signal  350  is an encoded combination of the output signal from each of receivers  208 ,  210 ,  212  and  214 . Any known method of transmitting the output signals from each of receivers  208 ,  210 ,  212  and  214  to controller  304  may be implemented, so long as controller  304  is able to distinguish which output signal corresponds to which of receivers  208 ,  210 ,  212  and  214 . In one non-limiting, example method of transmitting the output signals from each of receivers  208 ,  210 ,  212  and  214  to controller  304 , communication channel  318  provides a parallel combination of four signals, each of which corresponds to a respective one of receivers  208 ,  210 ,  212  and  214 . 
         [0102]    Controller  304  then compares the actual output signals from each of receivers  208 ,  210 ,  212  and  214  with the corresponding expected output signals for each of receivers  208 ,  210 ,  212  and  214 . If the actual output signal for any of receivers  208 ,  210 ,  212  and  214  does not coincide with the expected output signal within a predetermined threshold, then the receiver(s) in question is (or are) not performing correctly. 
         [0103]    In some embodiments, if any one of receivers  208 ,  210 ,  212  and  214  is not performing correctly, the incorrectly performing receiver(s) may be replaced, receiver array  204  may be replaced or device  300  may be replaced. 
         [0104]    In other embodiments, the incorrectly performing receiver(s) may be adjusted to correct the ill performance. For example, controller  304  may provide an adjustment signal  356 , via communication channel  322 , to receiver array  204  to adjust performance of the incorrectly performing receiver(s). After the ill performing receiver is adjusted, the testing is again performed. Again, if the adjusted receiver is still not performing correctly, the incorrectly performing receiver(s) may be replaced, receiver array  204  may be replaced or device  300  may be replaced. Alternatively, the ill performing receiver may again be adjusted by controller  304 . 
         [0105]    Now that receivers  208 ,  210 ,  212  and  214  have been tested, transmitters  216 ,  218  and  220  may be tested. 
         [0106]    In an example external testing mode, controller  304  sends a control signal  358  via communication channel  312  to transmitter array  206 , to serially enable each transmitter of transmitter array  206 . Control signal  358  not only enables a specific transmitter in transmitter array  206 , but control signal  358  additionally instructs the specifically enabled transmitter as to what signal to transmit. In particular, control signal  358  provides information related to parameters of the signal to be transmitted, non-limiting examples of such parameters include amplitude, frequency, phase, duration, etc. 
         [0107]    The output of each transmitter of transmitter array  206  is provided to power combiner  334 . Power combiner  334  combines the outputs from transmitters  216 ,  218  and  220 . However, only one of transmitter  216 ,  218  and  220  from transmitter array  206  is activated at a single time. 
         [0108]    Power combiner  334  then sends out a combined output signal  360  to output coupler  336 . Output coupler  336  has a known transfer function such that measured output signal  346  will have a predetermined functional relationship to combined output signal  360  with respect to predetermined parameters, non-limiting examples of which include amplitude, phase, frequency and combinations thereof. 
         [0109]    For purposes of discussion signal tester  106  then sends measured output signal  346  to controller  304  via communication channel  314 . 
         [0110]    During the test sequence, control signal  358  instructs transmitter  216  to transmit a known signal, which is output from power combiner  334  as combined output signal  360 . The transfer function of power combiner  334  and output coupler  336  are known. Further, the transfer function of transmitter  216  is anticipated. 
         [0111]    The expected measured output signal  346  corresponding to a signal from transmitter  216  is based on the known transfer function of each of power combiner  334  and output coupler  336  and the anticipated transfer function of each of transmitter  216 . In an example embodiment, this expected measured output signal is stored in controller  304 . 
         [0112]    In this manner, the actual measured output signal is provided to controller  304  as signal  362 . Controller  304  then compares the actual measured output signal corresponding to the signal transmitted from transmitter  216  with the corresponding expected measured output signal corresponding to the signal transmitted from transmitter  216 . If the actual measured output signal does not coincide with the expected measured output signal within a predetermined threshold, then transmitter  216  not performing correctly. 
         [0113]    In some embodiments, if transmitter  216  is not performing correctly, transmitter  216  may be replaced, transmitter array  206  may be replaced or device  300  may be replaced. 
         [0114]    In other embodiments, transmitter  216  may be adjusted to correct the ill performance. For example, controller  304  may provide an adjustment signal  364  to transmitter array  206  to adjust performance of transmitter  216 . After the ill performing transmitter is adjusted, the testing is again performed. Again, if adjusted transmitter  216  is still not performing correctly, adjusted transmitter  216  may be replaced, transmitter array  206  may be replaced or device  300  may be replaced. Alternatively, the ill performing adjusted transmitter  216  may again be adjusted by controller  304 . 
         [0115]    The remaining transmitters of transmitter array  206  are then similarly tested. 
         [0116]    Similar testing occurs for transceiver portion  328 . For purposes of discussion, it is a single transmitter and a single receiver that enables an external system to easily test transceiver portion  328 . 
         [0117]    The external testing mode as discussed above with reference to  FIG. 3A  very accurately tests each receiver in receiver array  204  and each transmitter in transmitter array  206 . However, the trade-off for accuracy is time, wherein extended time is needed to test, in parallel, all the receivers in receiver array  204  and then serially test all the transmitters in transmitter array  206 . In accordance with another aspect of the present invention, a loopback testing mode provides a much faster testing time, but at a cost of less accuracy for certain specifications. 
         [0118]    For instance, the absolute output power may be better determined by signal tester  106 , as discussed above with respect to a receiver compensating, for transmitter impairments. The relative phase balance of transmitters  216 ,  218  and  220 , however, may actually be better measured via a loopback testing method. This is primarily due to the difficulty of maintaining coherence between transceiver  302  and signal tester  106  during a test. In a loopback testing method, the coherence is guaranteed by a single clock source inside transceiver  302 . 
         [0119]    This will be described in greater detail with reference to  FIG. 3B . 
         [0120]      FIG. 3B  illustrates an example loopback testing mode of system  300  in accordance with aspects of the present invention. 
         [0121]    In the loopback testing mode, input coupler  330  of socket device  310  is used to couple an output signal from transmitter array  206  to receiver array  204 . In this mode, there is no use of signal generator  102  or signal tester  106 . 
         [0122]    Controller  304  sends control signal  366  to transmitter array  206 , to serially enable each transmitter of transmitter array  206 . The output of each transmitter of transmitter array  206  is provided to power combiner  334 . Power combiner  334  the sends out a combined output signal  368  to output coupler  336 . 
         [0123]    In a loopback testing mode, output coupler  336  couples combined output signal  368  to loopback line  338  as a coupled output signal  370 . As mentioned earlier, output coupler  336  has a known transfer function, wherein coupled output signal  370  will have a predetermined functional relationship to combined output signal  368  with respect to predetermined parameters, non-limiting examples of which include amplitude, phase, frequency and combinations thereof. 
         [0124]    Coupled output signal  370  is provided to input coupler  330  via loopback line  338 . Input coupler  330  then provides coupled output signal  370  to power divider  332  as signal  372 . As mentioned earlier, input coupler  330  has a known transfer function, wherein signal  372  will have a predetermined functional relationship to coupled output signal  370  with respect to predetermined parameters, non-limiting, examples of which include amplitude. phase, frequency and combinations thereof. In a similar manner as discussed above in  FIG. 3A , power divider  332  splits signal  372  to all receivers of receiver array  204 . 
         [0125]    During the test sequence, the transfer function of each of power combiner  334 , output coupler  336 , input coupler  330  and power divider  332  are known. In some embodiments, these transfer functions can be determined as part of a test hardware calibration procedure. Further, the transfer function of each of transmitters  216 ,  218 , and  220  and receivers  208 ,  210 ,  212  and  214  are anticipated. 
         [0126]    In an example loopback testing mode, controller  304  sends control signal  366  via communication channel  320  to transmitter array  206 , to serially enable each transmitter of transmitter array  206 . Control signal  366  not only enables a specific transmitter in transmitter array  206 , but control signal  366  additionally instructs the specifically enabled transmitter as to what signal to transmit. In particular, control signal provides information related to parameters of the signal to be transmitted, non-limiting examples of such parameters include amplitude, frequency, phase, duration, etc. 
         [0127]    Fur purposes of brevity, consider the ease where transmitter  216  is tested, along with all the receivers in receiver array  204 . In such a case, the transfer function of transmitter  216  and receivers  208 ,  210 ,  212  and  214  are anticipated. As mentioned previously, each transmitter in transmitter array  206  will have a known and expected transfer function, if it is operating correctly. 
         [0128]    As such, a signal  374  provided to power combiner  334  from transmitter  216  should have an expected functional relationship to the signal that transmitter  216  transmits, based on control signal  366  and based on the known transfer function of transmitter  216 . Similarly, combined output signal  368  should have a known functional relationship to signal  374 , based on the known transfer function of power combiner  334 . 
         [0129]    Coupled output signal  370  should have a known functional relationship to combined output signal  368 , based on the known transfer function of output coupler  336 . Further, signal  372  should have a known functional relationship to coupled output signal  370 , based on the known transfer function of input coupler  330 . Still further, the signal received each of receivers  208 ,  210 ,  212  and  214  should have a known functional relationship to signal  372 , based on the known transfer function of power divider  332 . 
         [0130]    The expected output signal from each of receivers  208 ,  210 ,  212  and  214  that correspond to control signal  366  is based on the known transfer function of each of power combiner  334 , output coupler  336 , input coupler  330  and power coupler  332  and the anticipated transfer function of each of transmitter  216  and receivers  208 ,  210 ,  212  and  214 . In an example embodiment, these expected output signals from receivers  208 ,  210 ,  212  and  214  are stored in controller  304 . 
         [0131]    In this manner, the actual output signal from each of receivers  208 ,  210 ,  212  and  214  are provided to controller  304  as a signal  376 . In some embodiments, signal  376  comprises a serial composition of an output signal from each of receivers  208 ,  210 ,  212  and  214 . In some embodiments, signal  376  is an encoded combination of the output signal from each of receivers  208 ,  210 ,  212  and  214 . Any known method of transmitting the output signals from each of receivers  208 ,  210 ,  212  and  214  to controller  304  may be implemented, so long as controller  304  is able to distinguish which output signal corresponds to which of receivers  208 ,  210 ,  212  and  214 . 
         [0132]    Controller  304  then compares the actual output signals from each of receivers  208 ,  210 ,  212  and  214  with the corresponding expected output signals for each of receivers  208 ,  210 ,  212  and  214 . 
         [0133]    As mentioned above with reference to the external testing, method of  FIG. 3A , if the actual output signal for any of receivers  208 ,  210 ,  212  and  214  does not coincide with the expected output signal within a predetermined threshold, then the receiver(s) in question is (or are) not performing correctly. 
         [0134]    However, in the loopback testing method of  FIG. 3B , if the actual output signal for any of receivers  208 ,  210 ,  212  and  214  does not coincide with the expected output signal within a predetermined threshold, then: a) the receiver(s) in question is (or are) not performing correctly; b) transmitter  216  is not performing correctly: or c) some combination of the receiver(s) in question and transmitter  216  is not performing correctly. 
         [0135]    Further, there may be an insidious situation wherein the actual output signal for all of receivers  208 ,  210 ,  212  and  214  coincides with the expected output signal within a predetermined threshold, but device  300  is not operating correctly. For example, consider the situation where signal  374  is 5° out of the expected phase and has an amplitude that is 0.1 dB too high, whereas each of receivers  208 ,  210 ,  212  and  214  provides output signals that are −5° out of the expected phase and have an amplitude that is 0.1 dB too low. In such a situation, signal  374  from an ill performing transmitter  216  is effectively hidden by the oppositely ill performing receivers  208 ,  210 ,  212  and  214 . 
         [0136]    The loopback testing mode as discussed with respect to  FIG. 3B  is much faster than the external test mode discussed above with respect to  FIG. 3A . However, there are problems with the loopback testing method, such as nor being able to discern whether the problem lies with a receiver or a transmitter. Further, with the loopback method, there is also the possibility that a malfunctioning transmitter is effectively hidden by an equal and oppositely malfunctioning receiver. This trade-off of speed versus accuracy between external and loopback testing methods is known. However, with a socket device in accordance with aspects of the present invention, all the transmitters in a transmitter array and all the receivers in a receiver array can easily be tested in either as loopback testing mode or an external testing mode, without making multiple connections/disconnections. 
         [0137]    In the example embodiment discussed above with reference to  FIGS. 3A-B , a single device was tested. In accordance with aspects of the present invention, a plurality of transceivers may be tested in parallel in a testing station. This will be described with additional reference to  FIG. 4 . 
         [0138]      FIG. 4  illustrates a system  400  for simultaneously testing a plurality of transceivers. 
         [0139]    As illustrated in the figure, system  400  includes a bank  402  of N signal testers and N signal generators, a sample of which are indicated as signal generator  102 , signal tester  106 , a signal generator  404  and a signal tester  406 . N is an integer greater or equal to two, wherein any additional sets of signal tester and signal generator are indicated by the dots  408 ,. 
         [0140]    Further illustrated in the figure, system  400  includes controller  304 , signal tester  306 , signal generator  308 , socket device  310 , socket device  312 , communication channel  112 , communication channel  118 , communication channel  120 , a communication channel  314 , communication channel  316 , a communication channel  318 , a communication channel  320 , a communication channel  322 , a communication channel  324  and a communication channel  326 , all as illustrated and discussed above with reference to  FIGS. 3A-B . 
         [0141]    Still further, system  400  additionally includes a signal tester  410 , a signal generator  412 , a controller  414 , a socket device  416  and a socket device  418 . 
         [0142]    In system  400 , signal tester  106  and signal generator  102 , each of bank  402 , are used during the external testing of transceiver  302 . Similarly, signal tester  406  and signal generator  404 , each of bank  402 , are used during the external testing of a transceiver  420 . 
         [0143]    Transceiver  420  includes a receiver array  422 , a transmitter array  424  and a transceiver portion  426 . Socket device  416  includes an input coupler  428 , a power divider  430 , a power combiner  432 , an output coupler  434  and a loopback line  436 . Transceiver portion  426  includes a transmitter  440  and a receiver  442 . Transceiver  420  is similar to transceiver  302 . 
         [0144]    A signal generator  404  operates in a manner similar to signal generator  102  and signal tester  406  operates in a manner similar to signal tester  106 . 
         [0145]    For purposes of brevity, it should be noted that transceiver  420  may be tested in a manner similar to the testing of transceiver  302  as discussed above with reference to  FIGS. 3A-B . System  400  represents that a plurality of transceivers may be tested simultaneously. 
         [0146]    The present invention enables a single transmit pin and a single receive pin enabling multi-site testing, two or more devices tested in parallel whereas the external test equipment for a traditional solution will have multiple sources and multiple receivers. 
         [0147]    As mentioned above, in a conventional transceiver having an array of receivers and an array of transmitters, each transmitter must be tested against each receiver. The conventional testing, as discussed above with reference to  FIGS. 2A-E , required multiple connections/disconnections to the external test equipment. Such a method is inefficient. It is possible that a conventional device itself has multiple signal generators and multiple signal testers. In accordance with aspects of the present invention, for the same test station that will require at least four signal generators and three signal testers for a conventional tester will only need each the use of one of the signal generators and one of the signal testers to be able to measure three parallel devices. 
         [0148]    A socket device in accordance with aspects of the present invention enables the transmitter array and the receiver array each be easily tested by way of an external testing mode or by way of a loopback mode. 
         [0149]    A socket device in accordance with aspects of the present invention provides benefits over conventional testing systems such as, the simultaneously support of self-test and conventional RF test with limited external hardware connections. Further, due to the reduced number of external hardware connections, a testing system that implements a socket device in accordance with the present invention can support higher multi-site without additional rigid waveguide based millimeter wave components. Finally, the stability of the self-test will not be limited by re-insertions and re-connecting the socket device because the loopback path does not go through any connectors. 
         [0150]    In the drawings and specification, there have been disclosed embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.