JP2014154924A - Calibration system and calibration method for connection apparatus for portable terminal test - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calibrate a variable attenuator which is provided in each branch path in a short time.SOLUTION: While monotonously changing from a reference value, attenuation amount data outputted from an attenuation amount control section 19 through a second resolution which is more precise than a first resolution in the state where a calibration signal Sin at a predetermined level is given from a signal generator 30 to a test device connection port 11 of a connection apparatus 10 for a portable terminal test, a calibration control device 60 causes a level measuring instrument 40 to measure an output level of a signal outputted from a terminal connection port 13 to be calibrated, acquires characteristics of an attenuation data couple output level and extracts from the acquired characteristics, attenuation amount data with which a difference of output levels becomes the first resolution, as a calibration value.

Description

  The present invention relates to a technique for calibrating a mobile terminal test connection device used for testing a plurality of mobile terminals such as a mobile phone and a smartphone in a short time.

  At the manufacturing site of mobile terminals, in order to efficiently inspect manufactured products, the test downlink signal is branched into a plurality of signals and supplied to a plurality of mobile terminals to be tested, and the output from the plurality of mobile terminals is output. A test system that performs a test by selectively receiving any one of link signals is known (for example, Patent Document 1).

  In this way, in a system in which a test downlink signal is distributed to a plurality of portable terminals and an uplink signal from the plurality of portable terminals is selectively received for testing, the downlink signal is branched. Loss varies from route to route due to slight differences in circuits, cables connected to portable terminals, and the like.

  If there is such a difference in loss for each path, the signal levels given to a plurality of portable terminals to be tested are different, and testing under the same conditions cannot be performed.

  In particular, in order to increase the number of connectable terminals, when using a mobile terminal test connection device (hereinafter simply referred to as a connection device) configured separately from the test device main body, the variation in loss due to the path difference is significant. Therefore, in order to correct the variation, a variable attenuator is inserted in each path, and a process for giving an equal loss to each path is required by controlling the amount of attenuation.

FIG. 6 shows a configuration example of the connection device 10 having the correction processing function. The connection apparatus 10 includes test apparatus connection ports 11 and 12 for connection to the test apparatus main body 100, and a plurality of N terminal connection ports 13 ₁ for connection to a plurality of N portable terminals 1 ₁ to 1 _N to be tested. and a ~13 _N.

  One test apparatus connection port 11 is a port for receiving a downlink signal from the test apparatus main body 100, and the other test apparatus connection port 12 outputs an uplink signal from the portable terminal to the test apparatus main body 100. In this example, these two ports 11 and 12 are separated from each other. However, by providing a directional coupler inside the connection device 10, one common test device connection port can be used. In some cases, signals may be input / output to / from the test apparatus main body 100.

The downlink signal input to the test apparatus connection port 11 is input to the distributor 14, branched into a plurality of N paths, and input to the variable attenuators 15 ₁ to 15 _N respectively inserted into the branched paths. is, in each of the variable attenuators ₁₅ 1 to 15 passes signals each coupler of _N (directional _coupler) 16 1 ~ 16 _N and the terminal connection ports _131-134 mobile via the _N terminal ₁ 1 to 1 _N Will be entered. The terminal connection ports 13 _{1 to} 13 _{N referred to} here are portions connected to the signal input terminal of the test-target mobile terminal, and in the case of connecting to the signal input terminal of the test-target mobile terminal via a cable. The end of the cable.

In addition, signals input from the terminal connection ports 13 _{1 to} 13 _N are input to the signal selector 17 via the couplers 16 _{1 to} 16 _N , and a designated signal is selected and is input to the test apparatus connection port 12. (This signal designation is made from the test apparatus main body 100).

The attenuation amounts of the variable attenuators 15 ₁ to 15 _N inserted in the respective branch paths are controlled by control signals V _{1 to} V _N given from the D / A converters 18 ₁ to 18 _N , respectively. 18 ₁ to 18 _N generate control signals V _{1 to} V _N corresponding to the attenuation amount data D _{A1 to} D _AN respectively set from the attenuation amount control unit 19.

The attenuation amount controller 19, necessary to provide equal loss corresponding to the specified lost data D _L in external test equipment predetermined resolution from the body 100 (e.g., 0.1 dB) in each branch path in the test mode attenuation The quantity data D _{A1 to} D _AN are configured to be supplied to the respective D / A converters 18 ₁ to 18 _N.

  Here, as described above, even if the same data is given to each D / A converter due to the difference in the branch paths and the characteristics of the D / A converter and the variable attenuator, the down output from the terminal connection port is performed. It is difficult to equalize the level of the link signal, and due to the difference in level, it is not possible to accurately test a plurality of portable terminals under the same conditions.

In order to eliminate this, attenuation data necessary for the actual loss between the input and output ports to be equal within the allowable error range with respect to the specified value is obtained in advance, and this is stored in the attenuation data storage unit 20. The attenuation amount control unit 19 reads the attenuation amount data corresponding to the loss data designated from the outside from the attenuation amount data storage unit 20 at the time of the test, and stores each D / A converter 18 _1. ~ 18 _N to give.

  When calibrating the connection apparatus 10 as described above, as shown in FIG. 7, the signal generator 30 is used instead of the test apparatus main body 100, and the level measuring instrument 40 is used instead of the portable terminal. A calibration system is used in which the connection device 10 can be controlled by a calibration control device 50 having a computer configuration.

And the calibration control apparatus 50 performs a calibration process according to the flowchart of FIG.
That is, first, a value n designating a branch path to be calibrated is initialized to 1 (S1), the level measuring device 40 is connected to the nth terminal connection port 13n (S2), and the loss designated to the connection device 10 is determined. the data _{D L} is set to the minimum Dmin (e.g. 00.00 in units of dB) (S3). Note that in this calibration mode, the attenuation amount controller 19 of the connection device 10, the lost data D _L designated from the outside, as it (including the case of performing change digit) each D / A converter as attenuation data 18 It assumed to have a function to give a ₁ ~ 18 _N.

  Then, the output of the signal generator 30 is set to a reference level (eg, 0 dBm), and the output frequency f is set to the lowest frequency Fmin (eg, 700 MHz) of the measurement range (S4).

In this state, the reference level calibration signal Sin output from the signal generator 30 is distributed approximately equally to the N path by the distributor 14 of the connection device 10, and the variable attenuator 15 is set to have an attenuation of approximately 0 dB. ₁ to 15 _N and output to each terminal connection port 13 _{1 to} 13 _N , and a signal output from the nth (n = 1 in this case) terminal connection port 13 n is input to the level measuring device 40. . Thus, when the attenuation data is 0, the loss generated between the input and output ports is a path loss that the path has steadily. If the level of the calibration signal is 0 dBm, the nth The signal level Ln output from the terminal connection port 13n becomes a path loss, and this value is stored (S5).

  Then, when the calibration point instruction value k is set to 1 and the resolution of the loss data designated from the test apparatus main body 100 in the test mode is 0.1 dB step, the output level is within the allowable error (Ln-0 .1 × k) Attenuation data is controlled until it becomes equal to dBm, and the attenuation data obtained by the tracking control is determined as attenuation data giving an actual loss of 0.1 × k (dB). This is stored as a calibration value (S6 to S8).

  In this tracking control, for example, the attenuation data at the current stage is increased by 0.1 dB, and after waiting for the fluctuation of the output signal level to settle, the output value is taken in, the output value is compared with the target value, When the difference is larger than the allowable error (for example, 0.005 dB), the process of changing the attenuation amount data according to the sign and the absolute value of the difference becomes equal to the target value within the allowable error. Repeat until.

  In the same manner, the process of storing the attenuation amount data is repeated so that the output level decreases by 0.1 dB from Ln, and the process of storing the attenuation amount data determined each time is performed. ) Minutes (that is, 20 / 0.1), the frequency of the calibration signal is changed by a predetermined value ΔF, and the above processing is repeated (S9, S10).

Thereafter, the above processing is repeated until the frequency reaches the upper limit value F _MAX , and then the terminal connection port to be calibrated is sequentially changed to the next port, and the above processing is repeated (S11 to 14).

Thereby, for each terminal connection port, attenuation data for giving an actual loss other than the path loss between the input and output is obtained for each measurement frequency, and these are written in the attenuation data storage unit 20 for the terminal test. Then, the attenuation amount control unit 19 reads out the attenuation amount data necessary for equally giving the loss corresponding to the value obtained by subtracting the path loss amount from the loss data designated from the test apparatus main body 100 to each branch path, and performs D / A conversion. By supplying to the devices 18 ₁ to 18 _N , it is possible to provide a test signal of the same level to all the terminal connection ports.

  A technique for calibrating such a variable attenuator is disclosed in Patent Document 2, for example.

JP-A-11-274998 JP 2003-18104 A

However, the specifications required for the connection device configured as described above are, for example, variable attenuation range necessary for the test = 20 dB (resolution 0.1 dB), frequency range = 700 MHz to 3.8 GHz (measurement interval 20 MHz), number of connectable terminals = Assuming 8 units, control of attenuation data
(20 / 0.1) × [(3800−700) / 20] × 8 = 248000 (times)
There is a need to do.

And, as described above, in the driving-in control for obtaining one attenuation amount data,
It is necessary to repeat the process of variable attenuation data → waiting output stabilization time → level measurement → error determination. The tracking control by the calibration system of the above calibration currently takes about 2 seconds per calibration point, and all points are calibrated. In addition,
248000 × 2 = 496000 (seconds) ≈ 138 (hours)
As a result, it took a huge amount of time for calibration.

  An object of the present invention is to solve this problem and to provide a calibration system and a calibration method for a portable terminal test connection device that can perform calibration for variable attenuators provided in each path in a short time.

In order to achieve the above object, a calibration system for a portable terminal test connection device of the present invention includes:
A test apparatus connection port (11) for receiving a downlink signal output from a test apparatus main body for portable terminal testing, and a distributor for branching the downlink signal input from the test apparatus connection port into a plurality of paths (14), a variable attenuator (15 ₁ to 15 _N ) inserted in each of the branched paths, and a plurality of D / Ds for supplying a control signal corresponding to the input attenuation amount data to the variable attenuator A converter (18 ₁ to 18 _N ), a plurality of terminal connection ports (13 _{1 to} 13 _N ) for inputting a signal that has passed through each of the variable attenuators to the portable terminal to be tested, and the test apparatus connection Attenuation data storage unit (2) that stores in advance attenuation data for each of the variable attenuators necessary for giving a loss equal to a plurality of paths from a port to each terminal connection port within a predetermined range with a first resolution. ) And controlling the attenuation amount of each variable attenuator by reading the attenuation amount data corresponding to the loss data designated from the outside from the attenuation amount data storage unit and giving it to each D / A converter, Loss data specified from the outside of the mobile terminal test connection device having an attenuation amount control unit (19) that gives a signal of the same level to a plurality of test target mobile terminals connected to each terminal connection port, and In the calibration system for associating the relationship with the attenuation data,
A signal generator (30) for providing a predetermined level of calibration signal to the test apparatus connection port of the mobile terminal test connection apparatus;
A level measuring device (40) for measuring the level of a signal output from the terminal connection port of the mobile terminal test connection device;
Attenuation monotonic variable means for monotonically changing the attenuation control data for the variable attenuator from a reference value with a second resolution finer than the first resolution to the attenuation control unit of the portable terminal test connection device (61) Attenuation in which the output level measured by the level measuring device is stored in association with the attenuation amount data while the attenuation amount data is monotonously changing at the second resolution by the attenuation amount monotonic variable means. Characteristic acquisition means (62), calibration value extraction for extracting attenuation data whose output level is the first resolution from the attenuation data versus output level characteristic obtained by the attenuation characteristic acquisition means as a calibration value And a calibration control device (60) for obtaining calibration values of attenuation amount data for the plurality of paths.

Moreover, the calibration system for the portable terminal test connection device according to claim 2 of the present invention is the portable terminal test connection device calibration system according to claim 1,
The calibration control device has frequency control means (64) for variably controlling the frequency of the calibration signal output from the signal generator, and obtains calibration values for different frequencies of the calibration signal. And

Moreover, the calibration method of the mobile terminal test connection device according to claim 3 of the present invention includes:
A test apparatus connection port (11) for receiving a downlink signal output from a test apparatus main body for portable terminal testing, and a distributor for branching the downlink signal input from the test apparatus connection port into a plurality of paths (14), a variable attenuator (15 ₁ to 15 _N ) inserted in each of the branched paths, and a plurality of D / Ds for supplying a control signal corresponding to the input attenuation amount data to the variable attenuator A converter (18 ₁ to 18 _N ), a plurality of terminal connection ports (13 _{1 to} 13 _N ) for inputting a signal that has passed through each of the variable attenuators to the portable terminal to be tested, and the test apparatus connection Attenuation data storage unit (2) that stores in advance attenuation data for each of the variable attenuators necessary for giving a loss equal to a plurality of paths from a port to each terminal connection port within a predetermined range with a first resolution. ) And controlling the attenuation amount of each variable attenuator by reading the attenuation amount data corresponding to the loss data designated from the outside from the attenuation amount data storage unit and giving it to each D / A converter, Loss data specified from the outside of the mobile terminal test connection device and the attenuation having an attenuation amount control unit (19) that gives a signal of the same level to a plurality of test target mobile terminals connected to each terminal connection port In the calibration method for associating the relationship with the quantity data,
Providing a calibration signal of a predetermined level to the test device connection port of the mobile terminal test connection device;
Output from the terminal connection port while monotonically changing the attenuation amount data for the variable attenuator by the attenuation amount control unit of the portable terminal test connection device from a reference value with a second resolution finer than the first resolution. Measuring the output level of the received signal and obtaining the characteristics of the attenuation data versus the output level;
A step of extracting, as a calibration value, attenuation data in which the difference in output level is the first resolution from the acquired attenuation data versus output level characteristic.

According to a fourth aspect of the present invention, there is provided a calibration method for a mobile terminal test connection device according to the third aspect of the present invention.
Including a step of changing a frequency of the calibration signal, and determining a calibration value of attenuation data for the plurality of paths at different frequencies of the calibration signal.

  As described above, according to the present invention, the attenuation amount data output from the attenuation amount control unit in the state in which the calibration signal of a predetermined level is given to the test device connection port of the connection device for portable terminal test is the first value from the reference value. Measure the output level of the signal output from the terminal connection port to be calibrated while monotonically changing at the second resolution finer than the resolution, obtain the characteristics of attenuation data versus output level, and from the obtained characteristics, Since attenuation data whose output level difference is the first resolution is extracted as a calibration value, it is not necessary to perform additional control of attenuation data for each calibration point, and even if there are many terminal connection ports. The calibration process can be completed in a very short time.

Configuration diagram of a calibration system according to an embodiment of the present invention The flowchart which shows the process sequence of the principal part of embodiment. The figure for demonstrating operation | movement of embodiment The figure which shows the example of the fluctuation | variation of the output level in the minute monotone change period of attenuation amount data Diagram showing the relationship between the obtained characteristic data and the calibration value of attenuation data Configuration diagram of a system for testing a plurality of portable terminals using a connection device System configuration for calibrating connected devices Flow chart showing conventional calibration procedure

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows the configuration of a calibration system for a connection device to which the present invention is applied.

  Since the connection device 10 to be calibrated by this calibration system is the same as that described above, the same reference numerals are given to the respective components and description thereof is omitted.

  The signal generator 30 that outputs the calibration signal and the level measuring device 40 that measures the level of the signal output from the terminal connection port are the same as those in the calibration system described above.

  The calibration control device 60 of the calibration system has a computer configuration, and controls the signal generator 30, controls the level measuring device 40, acquires measurement results, controls the attenuation control unit 19 of the connection device 10, and the like.

  The calibration control device 60 includes an attenuation amount monotonic variable means 61, an attenuation characteristic acquisition means 62, a calibration value extraction means 63, a frequency control means 64, and an attenuation amount data update means 65.

The attenuation amount monotonous variable means 61 supplies attenuation amount data to be given to the D / A converters 18 ₁ to 18 _N respectively corresponding to the variable attenuators 15 ₁ to 15 _N to the attenuation amount control unit 19 of the connection device 10. For example, an instruction is given to monotonously increase with a second resolution (eg, 0.01 dB) finer than the first resolution (0.1 dB in the above example) with the minimum value of 0.00 dB as a reference. In this example, the variable range of the monotonic change of the attenuation amount data is set slightly wider (for example, 0-20 + α α = 3 dB) than the attenuation amount range (0-20 dB) used in the test mode, and the range of 0-20 dB. The data that gives the actual attenuation can be extracted reliably. In this example, the change is monotonously based on the minimum attenuation state. However, in the above-described range, for example, the attenuation data is set to the minimum attenuation state based on the state where the attenuation data is set to 23 dB. You may change monotonously.

  The attenuation characteristic acquisition unit 62 outputs the output level measured by the level measuring device 40 during the period in which the attenuation amount data is monotonically changing from the reference value at the second resolution according to the instruction of the attenuation amount monotonous variable unit 61. And stored in an internal memory (not shown).

  Various methods can be considered for controlling the acquisition start timing of the attenuation amount data vs. output level characteristic by the attenuation characteristic acquisition means 62 according to the structure of the level measuring device 40.

  For example, when the level measuring device 40 is an oscilloscope (including the case where the sweep frequency of the spectrum analyzer is stopped in a state in which the sweep frequency of the spectrum analyzer matches the input signal frequency and time domain measurement is performed), the input signal steeply rises above a predetermined level. When a level trigger function for starting sampling of an input signal after a change (or falling change) is provided, the attenuation characteristic acquisition unit 62 is configured to store the attenuation amount data by the attenuation amount monotonous variable unit 61. Prior to the monotonous variable, the attenuation amount is step-changed to the reference value within a predetermined width. Further, when the level measuring device 40 has a trigger dedicated terminal of a different system from the signal input terminal, a configuration may be adopted in which a trigger clock whose level transitions in synchronization with the measurement start timing is given to the trigger dedicated terminal.

  The level measuring device 40 samples the input signal from the trigger timing, stores the acquired series of characteristic data therein, and stores the stored series of characteristic data in the external device (in this case, the calibration control device 60). ) At the timing when the monotonic change of the attenuation amount data reaches the final value and the sampling of the output level is completed, the level measurement from the attenuation characteristic acquisition means 62 is performed. A request is made to send characteristic data to the device 40, and a series of characteristic data stored in the internal memory of the level measuring device 40 is sent to the calibration control device 60.

  Further, the level measuring device 40 does not have a trigger function as described above or a function of storing a series of sampled characteristic data and then sending them together, and performs sampling on the input signal and output of the sampling result. In the case of a configuration that is constantly performed, the level measuring device 40 outputs the period from the timing when the attenuation amount monotonic variable means 61 sets the attenuation amount data to the reference value until the attenuation amount data changes to the final value. Capture sampling data.

  The calibration value extraction unit 63 extracts attenuation data whose output level difference becomes the first resolution as a calibration value from the attenuation data versus output level characteristic obtained by the attenuation characteristic acquisition unit 62.

  This calibration value extraction process was sampled during the stable period before the next attenuation change, after the transient fluctuation period immediately after the attenuation change in the characteristic data of the attenuation data versus the output level. Data is the target (if the data is one, use that data, and if there is more than one, use the intermediate value or average value).

  The frequency control means 64 variably controls the frequency of the calibration signal output from the signal generator 30. When the level measuring device 40 is a variable measurement frequency type, the measurement frequency is set to the frequency of the calibration signal. Control to match.

  The attenuation amount data update unit 65 gives the calibration value of the attenuation amount data obtained by the calibration value extraction unit 63 to the attenuation amount control unit 19 of the connection device 10, and uses the attenuation amount data for the attenuation amount data storage unit 20 as the calibration value. Update.

  FIG. 2 is a flowchart showing a processing procedure of the calibration control device 60 having the above-described configuration. The operation example of the calibration system according to the embodiment will be described below based on this flowchart. In this operation example, the level measuring device 40 has a trigger function described above and a function for storing a series of sampled characteristic data in an internal memory and sending the stored characteristic data together in response to a request from an external device. A spectrum analyzer that can measure the time domain of the input signal is used.

First, a value n designating the branch path to be calibrated is initialized to 1 (S21), the level measuring device 40 is connected to the nth terminal connection port 13n (S22), and loss data D designated to the connection device 10 is set. _As shown in FIG. 3A, _{L is set} to the maximum value Dmax of the variable range that covers the calibration range of 0 to 20 dB (for example, 20.00 + αα in units of dB is 3 dB, for example) (S23). Further, as described above, the attenuation amount controller 19 of the connecting device 10 in the calibration mode, the lost data D _L designated from the outside, as it (including change digit) each D / A converter 18 _1-18 It is assumed that it has a function given to _N.

  Then, the output of the signal generator 30 is set to a reference level (for example, 0 dBm), and the measurement frequency f is set to the lowest frequency Fmin (for example, Fmin = 700 MHz) in the measurement range (S24).

In this state, the reference level calibration signal Sin output from the signal generator 30 is distributed approximately equally to the N path by the distributor 14 of the connection device 10, and is adjusted by the variable attenuators 15 ₁ to 15 _N of the branch paths. The signal is output to the terminal connection ports 13 _{1 to} 13 _N after being attenuated by about 23 dB, and the signal output from the n-th (n = 1 in this case) terminal connection port 13 _n is output to the level measuring device 40. Entered. At this time, the attenuation amount of each of the variable attenuators 15 ₁ to 15 _N is as large as about 23 dB, and the path corresponding to the terminal connection port _{13 n} includes path loss other than the variable attenuator. The input signal level is low, the trigger is not applied, and the level detection process by the level measuring device 40 is not started.

In this state, calibration controller 60 changes the loss data _{D L} for designating to the connection adapter 10, the minimum value Dmin (0.00 in units of dB) (S25).

For this reason, the amount of attenuation of each of the variable attenuators 15 ₁ to 15 _N changes suddenly from approximately 23 dB to 0 dB, the input signal level of the level measuring device 40 increases by approximately 23 dB, and the trigger function is activated so that the level measuring device 40 The level detection process is started at a predetermined sampling cycle Ts, and the detected level data is sequentially stored in a memory in the level measuring device 40, for example.

  However, since a transient fluctuation occurs in the output level due to this sudden change in attenuation, the process waits for a period until the fluctuation converges (time T1 in FIG. 3B) (S26).

After this change is stabilized to converge, the attenuation amount controller lost data D _L to instruct the 19, the resolution (first resolution 0.1 dB) loss data specified in the test mode finer second Is increased monotonically from the reference value (minimum value Dmin) to the maximum value Dmax at step Δd with a resolution of 0.01 dB (for example, 0.01 dB) (S27).

  Since the actual change amount of the attenuation amount in this monotonous change period (C in FIG. 3) is as small as about 0.01 dB, as shown in FIG. 4, the output level transient fluctuation period Tv is as short as 500 μS or less, for example. . Accordingly, if the monotonous change interval T2 is set to 1 mS, for example, the stable period Ta obtained by excluding the transient fluctuation period Tv from the time T2 is 500 μS or more, and the sampling period Ts by the level measuring device 40 is, for example, 100 μS, which is 1/10 of the time T2. If so, about 5 sampling values (indicated by black circles in the figure) are obtained during the stable period Ta.

  In this way, the loss data designated for the connection device 10 is monotonously changed from the reference value in a minute step of the second resolution, thereby reducing the attenuation amount to the variable attenuator at one measurement frequency for the n-th branch path. Characteristic data representing the relationship between the data and the actual output level is obtained, and a series of characteristic data stored in the level measuring device 40 is obtained at the timing when the level data is obtained by changing the loss data until the final stage. The calibration control device 60 takes in a series of characteristic data sent from the level measuring device 40 (S28).

  The processing from S25 to S28 is repeated every time the frequency is increased by a predetermined step ΔF (for example, ΔF = 20 MHz), and is repeated up to the maximum value Fmax (for example, Fmax = 3.8 GHz). Characteristic data representing the relationship between the attenuation amount data for all the measurement frequencies and the actual output level is obtained (S29, S30).

  After the characteristic data for the n-th branch path is obtained in this way, n is updated by 1, and the processes S22 to S30 are performed in the same manner as described above, whereby attenuation for all frequencies related to the next branch path is performed. Characteristic data representing the relationship between the quantity data and the actual output level is obtained. If this is performed up to n = N, characteristic data for all measurement frequencies for all branch paths can be obtained (S31, S32).

  Then, from the characteristic data obtained as described above, the amount of attenuation necessary for equally giving a loss of the first resolution (eg, 0.1 dB) coarser than the second resolution (0.01 dB) to each branch path. The data is extracted as calibration data, and the extracted data is given to the connection device 10 to update the content of the attenuation amount data storage unit 20, thereby completing the calibration process (S33, S34).

The calibration data is extracted from the characteristic data as shown in FIG. 5, for example.
That is, the characteristic data obtained by the measurement for one terminal connection port at a certain measurement frequency is shown in FIG. In FIG. 5A, the designated value in the left column is attenuation data to the D / A converter corresponding to the designated loss data, and designated loss data 00.00 to 20.00 + α (dB) is obtained. Data changed to 4-digit integers are supported. Further, the right column is a measured value of the output level, which is determined based on the data sampled during the above-described stable period Ta. When the input level of the calibration signal is 0 dBm, the measured value −10.09 (dBm) obtained when the initial value is 0000 is the path loss that is steadily present in the measurement target port. Is Ln.

  In this measurement result, the measured value becomes equal to Ln−0.1 = −10.19 (dBm) when the attenuation amount data is 0010, which matches the theoretical value.

  The measured value is equal to Ln−0.1 × 2 = −10.29 (dBm) when the attenuation data is 0021, and an error occurs when the theoretical data 0020 is specified. .

  In the same manner, attenuation data whose measured value is the resolution of loss data specified in the test state (in this case, 0.1 dB) is extracted as a calibration value.

  (B) of FIG. 5 shows the actual attenuation by the variable attenuator and the attenuation data to be given to the D / A converter to realize the attenuation based on the calibration data extracted as described above. It shows the correspondence.

The path loss Ln described above and the content of FIG. 5B are stored in the attenuation amount data storage unit 20, and in the test state, the loss greater than the path loss Ln with a resolution of 0.1 dB with respect to the path to be tested. When the data _DL is designated, the attenuation control unit 19 determines the difference between the two,
D _L −Ln = ΔL
And the attenuation amount data corresponding to the actual attenuation amount equal to the difference ΔL in the left column of FIG. 5B is selected and set in the D / A converter of the target path.

As a result, the loss of the target path accurately corresponds to the designated loss _DL data. If this process is performed in parallel for all routes, the loss in all routes can be set equal, and the same level test signal can be given to a plurality of portable terminals connected to the terminal connection ports of those routes. it can.

  As described above, in the calibration system of the embodiment, attenuation data to be supplied to the D / A converter corresponding to each variable attenuator inserted in each path is finer than the resolution of loss data specified in the test state. The attenuation data vs. output level characteristic data is obtained by monotonically changing the data in various steps, and the attenuation data whose output level changes with the resolution of the loss data specified in the test state is extracted from the characteristic data as calibration data. ing.

  For this reason, as in the conventional tracking control, the attenuation data is varied for each calibration point within a range close to the resolution of the loss data specified in the test state, and the resulting transient fluctuation period is waited for. It is not necessary to repeat the process of obtaining the difference from the value and increasing / decreasing the attenuation amount data according to the sign and absolute value of the difference, and the calibration process can be completed in a very short time.

Here is a numerical example. For example, if the transient variation convergence time T1 associated with the trigger sweep is 100 mS, the monotonic variable interval T2 of the attenuation data is 1 mS, the variable range of the attenuation data is 20 dB, and the variable step is 0.01 dB, one measurement frequency, The time required to acquire characteristic data per route is
(20 / 0.01) × 1 + 100 = 2100 mS = 2.1S
It becomes.

  Even if characteristic data acquisition or calibration data extraction processing is added to this, it takes only about 3 to 4 seconds at the most (note that the time required for characteristic data acquisition is short, and the acquisition processing is performed for the next characteristic data. It can be done in parallel during acquisition and can be ignored).

And, if the above time is 4 seconds, the frequency range = 700 MHz to 3.8 GHz (measurement interval 20 MHz), and the number of connectable terminals = 8, the time required to acquire the characteristic data of all measurement frequencies and all paths is
4 × (3100/20) × 8 = 4960S≈83 minutes, and it can be seen that this is much faster than the method in which the additional control is performed for each calibration point described above.

  In the embodiment, in order to use the trigger function of the level measuring device 40, the loss data is suddenly changed from the maximum value to the minimum value. When using a configuration that constantly performs level detection processing and its output, the loss data is changed from the initial value (minimum value or maximum value) to the second resolution step without changing the trigger data. What is necessary is just to take in a measured value, making it change monotonously. In this case, the convergence waiting time T1 is almost unnecessary, so that the calibration process can be completed in a short time.

DESCRIPTION OF SYMBOLS 10 ... Connection apparatus for portable terminal test, 11 ... Test apparatus connection port, 13 _{1 to} 13 _N ... Terminal connection port, 14 ... Distributor, 15 ₁ to 15 _N ... Variable attenuator, 18 ₁ to 18 _N: D / A converter, 19: Attenuation amount control unit, 20: Attenuation amount data storage unit, 30 ... Signal generator, 40 ... Level measuring device, 60 ... Control device for calibration, 61 ... Attenuation amount monotonic variable means 62 ... Attenuation characteristic acquisition means 63 ... Calibration value extraction means 64 ... Frequency control means 65 ... Attenuation data update means 100 ... Test device body

Claims (4)

A test apparatus connection port (11) for receiving a downlink signal output from a test apparatus main body for portable terminal testing, and a distributor for branching the downlink signal input from the test apparatus connection port into a plurality of paths (14), a variable attenuator (15 ₁ to 15 _N ) inserted in each of the branched paths, and a plurality of D / Ds for supplying a control signal corresponding to the input attenuation amount data to the variable attenuator A converter (18 ₁ to 18 _N ), a plurality of terminal connection ports (13 _{1 to} 13 _N ) for inputting a signal that has passed through each of the variable attenuators to the portable terminal to be tested, and the test apparatus connection Attenuation data storage unit (2) that stores in advance attenuation data for each of the variable attenuators necessary for giving a loss equal to a plurality of paths from a port to each terminal connection port within a predetermined range with a first resolution. ) And controlling the attenuation amount of each variable attenuator by reading the attenuation amount data corresponding to the loss data designated from the outside from the attenuation amount data storage unit and giving it to each D / A converter, Loss data specified from the outside of the mobile terminal test connection device and the attenuation having an attenuation amount control unit (19) that gives a signal of the same level to a plurality of test target mobile terminals connected to each terminal connection port In the calibration system for associating the relationship with the quantity data,
A signal generator (30) for providing a predetermined level of calibration signal to the test apparatus connection port of the mobile terminal test connection apparatus;
A level measuring device (40) for measuring the level of a signal output from the terminal connection port of the mobile terminal test connection device;
Attenuation monotonic variable means for monotonically changing the attenuation control data for the variable attenuator from a reference value with a second resolution finer than the first resolution to the attenuation control unit of the portable terminal test connection device (61) Attenuation in which the output level measured by the level measuring device is stored in association with the attenuation amount data while the attenuation amount data is monotonously changing at the second resolution by the attenuation amount monotonic variable means. Characteristic acquisition means (62), calibration value extraction for extracting attenuation data whose output level is the first resolution from the attenuation data versus output level characteristic obtained by the attenuation characteristic acquisition means as a calibration value And a calibration control device (60) for obtaining a calibration value of attenuation amount data for the plurality of paths, and a calibration system for a connection device for portable terminal testing, comprising: means (63) Beam.   The calibration control device has frequency control means (64) for variably controlling the frequency of the calibration signal output from the signal generator, and obtains calibration values for different frequencies of the calibration signal. A calibration system for a portable terminal test connection device according to claim 1. A test apparatus connection port (11) for receiving a downlink signal output from a test apparatus main body for portable terminal testing, and a distributor for branching the downlink signal input from the test apparatus connection port into a plurality of paths (14), a variable attenuator (15 ₁ to 15 _N ) inserted in each of the branched paths, and a plurality of D / Ds for supplying a control signal corresponding to the input attenuation amount data to the variable attenuator A converter (18 ₁ to 18 _N ), a plurality of terminal connection ports (13 _{1 to} 13 _N ) for inputting a signal that has passed through each of the variable attenuators to the portable terminal to be tested, and the test apparatus connection Attenuation data storage unit (2) that stores in advance attenuation data for each of the variable attenuators necessary for giving a loss equal to a plurality of paths from a port to each terminal connection port within a predetermined range with a first resolution. ) And controlling the attenuation amount of each variable attenuator by reading the attenuation amount data corresponding to the loss data designated from the outside from the attenuation amount data storage unit and giving it to each D / A converter, Loss data specified from the outside of the mobile terminal test connection device and the attenuation having an attenuation amount control unit (19) that gives a signal of the same level to a plurality of test target mobile terminals connected to each terminal connection port In the calibration method for associating the relationship with the quantity data,
Providing a calibration signal of a predetermined level to the test device connection port of the mobile terminal test connection device;
Output from the terminal connection port while monotonically changing the attenuation amount data for the variable attenuator by the attenuation amount control unit of the portable terminal test connection device from a reference value with a second resolution finer than the first resolution. Measuring the output level of the received signal and obtaining the characteristics of the attenuation data versus the output level;
Calibration of the portable terminal test connection device, comprising: extracting from the acquired attenuation data vs. output level characteristics attenuation data whose output level is the first resolution as a calibration value. Method.   The portable terminal test connection according to claim 3, further comprising a step of changing a frequency of the calibration signal, and determining a calibration value of attenuation data for the plurality of paths at different frequencies of the calibration signal. Device calibration method.

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