JP3077642B2 - Strain characteristic measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distortion characteristic measuring device for measuring a distortion characteristic of a semiconductor device.

[0002]

2. Description of the Related Art Along with digitization of communication, an amplifier for amplifying a signal with low distortion is required for a communication apparatus. For this reason, a semiconductor element constituting the amplifier is required to have a low distortion. When the semiconductor device is produced,
The distortion characteristics of the semiconductor element are measured. This allows
A low-distortion semiconductor element can be supplied. Some distortion characteristic measuring devices use a plurality of signal sources based on the standard for measuring distortion characteristics.
0 is shown. The measuring device shown in FIG.
Sn, a multiplexer 201, a spectrum analyzer 202,
A controller 203 and terminals 204A and 204B are provided.

Prior to distortion measurement using the above-described distortion characteristic measuring device, a device under test (DUT) attached to terminals 204A and 204B at each point of frequencies f1,... test) The output power of the signal output by A needs to be within the standard. For this,
The signal sources SS1,..., SSn of the distortion characteristic measuring device are:
, Fn are oscillated by oscillators G1,..., Gn, and further attenuators ATT1,.
After that, it is added to the multiplexer 201. Upon receiving the signals of the frequencies f1,..., Fn, the multiplexer 201 multiplexes the signals and sends them to the terminal 204A. Terminals 204A and 204B
Since the device under test A is connected, the multiplexed signal from the multiplexer 201 is added to the device under test A.

Since the device under test A is a semiconductor device and also an amplifier, distortion occurs during amplification. The signal amplified by the device under test A is transmitted to the spectrum analyzer 20.
Added to 2. The spectrum analyzer 202 checks the waveform of the output power from the device under test A. Then, the spectrum analyzer 202 sends the analysis waveform of the output power to the controller 203. The controller 203
Based on the analysis waveform from the spectrum analyzer 202, at the points of the frequencies f1,.
The signal sources SS1,..., S so that the power level is within the standard
Adjust the Sn attenuators ATT1,..., ATTn.

In order to keep the above power levels within the standard,
The controller 203 controls the attenuators ATT of the signal sources SS1,.
1, ..., ATTn are adjusted. The controller 203
One of the signal sources SS1,..., SSn, for example, the output of the signal source SS1 is set (step S21). Thereby, the signal source SS1 adjusts the attenuator ATT1 to set the level of the signal from the oscillator G1 to the specified value. After step S21, the controller 203 reads an analysis waveform, which is an output waveform from the spectrum analyzer 202 (step S22), and compares it with an ideal output waveform stored in advance (step S23). The ideal output waveform is created based on the standard.
If the analysis waveform is not within the standard in step S23, the controller 203 repeats the processing in steps S21 and S22.

In step S23, if the waveform of the output power is within the standard, the controller 203
It is checked whether all adjustments for 1,..., SSn have been completed (step S24). When all the adjustments of the signal sources SS1,..., SSn are completed, the controller 203 ends the output adjustment processing. If all adjustments have not been completed in step S24, the controller 203
Selects the next signal source SS2 (step S25), and returns the process to step S21. In this way, the distortion characteristic measuring apparatus adjusts the signal sources SS1,..., SSn, and at each point of the frequencies f1,.
Make the output power of the signal output from within the standard. Thereafter, the distortion characteristic measuring device starts measuring the distortion of the DUT A.

[0007]

However, the above prior art has the following problems. In other words, according to the distortion characteristic measuring apparatus, the controller 203 switches the signal source SS1 from the signal source SS1 so that the output power of the signal output from the device under test A falls within the standard at each of the frequencies f1,. Steps S21 to S21 in FIG.
Step 23 is repeated. Therefore, as shown by a line 301 in the graph of FIG.
That is, as the number of signal sources included in the distortion characteristic measuring device increases, the processing time increases, and there is a problem that it takes time to measure the DUT A.

The present invention has been made in view of the above circumstances, and when measuring and measuring a distortion characteristic of an object to be measured, a process for setting output power of a signal from the object to be measured is performed in a short time. It is an object of the present invention to provide a distortion characteristic measuring device capable of performing the measurement.

[0009]

In order to solve the above-mentioned problems, an invention according to claim 1 is a first terminal and a second terminal to which an input side and an output side of an object to be measured are respectively attached. And n signal sources each outputting signals of n (n is an arbitrary natural number, the same applies hereinafter) frequencies, and a multiplexer for multiplexing signals from the n signal sources. A power level of a signal from the multiplexer is adjusted at each of the frequencies, and an equalizer for applying the level-adjusted signal to the first terminal and an output waveform of output power from the second terminal are examined. From a spectrum analyzer and an ideal waveform stored in advance, and the amplitude characteristics of the device under test that have been checked in advance, control data for converting the output waveform to the ideal waveform is generated and sent to the equalizer,
After that, a control unit that compares the analysis waveform from the spectrum analyzer with the ideal waveform and sends a difference between the analysis waveform and the ideal waveform to the equalizer, the equalizer receives the control data And adjusting the power level of each frequency based on the control data, and adjusting the power level of the corresponding frequency when the difference is received.

According to this configuration, first, an object to be measured is mounted between the first terminal and the second terminal. Thereafter, the n signal sources output signals of n frequencies, respectively, and the multiplexer multiplexes the signals from the n signal sources and adds the multiplexed signals to the equalizer. On the other hand, the control unit
Control data for converting the output waveform into the ideal waveform is generated from the ideal waveform and the amplitude characteristics, and the control data is sent to the equalizer. Upon receiving the control data, the equalizer adjusts the power level of each of the frequencies of the signal from the multiplexer based on the control data. Thereafter, the equalizer applies the signal whose level has been adjusted to the first terminal.

Thus, the device under test amplifies the signal and applies the amplified signal to the second terminal. The spectrum analyzer checks an output waveform of the output power from the second terminal and outputs an analysis waveform. The control unit compares the analysis waveform from the spectrum analyzer with the ideal waveform, and sends a difference between the analysis waveform and the ideal waveform to the equalizer. Upon receiving the difference, the equalizer adjusts the power level of the corresponding frequency. Thus, when measuring the distortion characteristics of the device under test, the output power of the signal from the device under test is set.

According to a second aspect of the present invention, there is provided the distortion characteristic measuring apparatus according to the first aspect, wherein the control section includes a reading section for outputting the amplitude characteristic, an amplitude characteristic from the reading section,
From the ideal waveform, control data for converting the output waveform to the ideal waveform is generated and sent to the equalizer. Thereafter, the analysis waveform from the spectrum analyzer is compared with the ideal waveform, and the analysis waveform is And a controller for sending a difference between the equalizer and the ideal waveform to the equalizer.

According to a third aspect of the present invention, there is provided the distortion characteristic measuring apparatus according to the second or third aspect, wherein the reading section stores amplitude characteristics of a plurality of DUTs. I have. According to a fourth aspect of the present invention, there is provided the distortion characteristic measuring apparatus according to the first, second or third aspect, wherein the amplitude characteristic is measured using a network analyzer.

The invention according to claim 5 is the invention according to claims 1, 2, and 3
Or the distortion characteristic measuring device according to 4, wherein the equalizer is configured to amplify a signal from the multiplexer in a frequency band including the range of n frequencies, and to receive the control data, A slope attenuator for adjusting the power level by changing the degree of attenuation of each frequency based on the control data. According to a sixth aspect of the present invention, there is provided the distortion characteristic measuring device according to the second, third, fourth, or fifth aspect, wherein the control unit includes a directional coupling inserted between the equalizer and the first terminal. And the output power from the second terminal or the output power from the directional coupler, which is connected between the second terminal and the spectrum analyzer and controlled by the controller. A controller that sends the waveform of output power from the directional coupler from the spectrum analyzer, checks the current characteristics of the equalizer, and checks the current characteristic of the equalizer. , The amplitude characteristic from the reading section, and the ideal waveform, to generate control data and send it to the equalizer. Wherein the analysis waveform from by comparing the ideal waveform, and the difference between the analysis waveform and the ideal waveform and wherein the sending the equalizer.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a block diagram schematically showing a configuration of a distortion characteristic measuring device according to a first embodiment of the present invention, and FIG. 2 shows waveform data of an equalizer of the distortion characteristic measuring device. FIG. 3 is a waveform diagram showing an actually measured output waveform from a spectrum analyzer of the distortion characteristic measuring device, FIG. 4 is a waveform diagram showing measurement data from a reading section of the distortion characteristic measuring device, and FIG.
Is a waveform diagram showing an ideal output waveform stored by the controller of the distortion characteristic measuring device, FIG. 6 is a flowchart showing processing of the controller of the distortion characteristic measuring device, and FIG. It is a graph shown.

As shown in FIG. 1, the distortion characteristic measuring apparatus includes signal sources SG1,..., SGn, a multiplexer 1, an equalizer 2, a spectrum analyzer 3, a reading unit 4, a controller 5, and terminals 6A and 6B. Has become. The signal sources SG1,..., SGn output signals of frequencies f1,.
The multiplexer 1 has a frequency f from the signal sources SG1,..., SGn.
When receiving the signals of 1,..., Fn, the signals are multiplexed and sent to the equalizer 2.

As shown in FIG. 1, the equalizer 2 includes an amplifier 2A and a slope attenuator 2B. The amplifier 2A is a broadband amplifier that amplifies a signal including a frequency range up to frequencies f1,..., Fn. The slope attenuator 2B is an attenuator capable of varying the attenuation at each point of the frequencies f1,..., Fn. Upon receiving the control data from the controller 5, the equalizer 2 controls the slope attenuator 2B. Thereby, the equalizer 2 adjusts the power level of the signal from the multiplexer 1 at each point of the frequencies f1,.
The waveform data a shown in FIG. The equalizer 2 adjusts the power level of the signal to be transmitted to the device under test A based on the waveform data a, and changes the output power to a waveform b. Further, when the equalizer 2 receives the data indicating the difference from the controller 5, based on the difference, the slope attenuator 2B
At the point of the corresponding frequency
Change the power level of the signal sent to. Thereby, the equalizer 2 corrects the waveform data a.

[0018] The spectrum analyzer 3
Upon receiving the output signal from, the spectrum of the output power of this signal is analyzed. Thus, the spectrum analyzer 3 generates an actually measured output waveform c of the output power as shown in FIG. 3 as an analysis waveform. The spectrum analyzer 3 sends the generated measured output waveform c to the controller 5.

The reading section 4 is a device for internally incorporating a storage medium (not shown) for storing data and for reading measurement data from the storage medium. The measurement data is created in advance using a network analyzer. The network analyzer examines the characteristics of the device under test A using signals of different frequencies applied to the device under test A and signals output from the device under test A when the signals are added. In this embodiment, the amplitude characteristics indicating the power gain of the device under test A are examined in the range of frequencies f1,..., Fn using the network analyzer. FIG. 4 shows the amplitude characteristics of the DUT A thus obtained.
Is recorded on the recording medium as the measurement data d shown in FIG. The reading unit 4 stores measurement data of each semiconductor element in a recording medium. When reading the measurement data d of the device under test A from the recording medium, the reading unit 4 sends the measurement data d to the controller 5.

The controller 5 has a CPU (central process).
ssing unit) and a ROM (re
ad only memory), RAM (random acc.
essmemory) inside. As shown in FIG. 5, the controller 5 stores a waveform of the output power from the device under test A according to the standard for measuring the distortion characteristic, that is, an ideal output waveform e.

The controller 5 has an ideal output waveform e.
Is used to perform the output control processing shown in FIG. When this process is started, the controller 5 takes in the measurement data d from the reading unit 4 (Step S1). Upon receiving the measurement data d, the controller 5 uses the ideal output waveform e stored in advance and the measurement data d to generate the frequencies f1,.
The power level at each of the n points is checked, and the waveform of the input power required for the device under test A is calculated (step S2). The waveform calculated in step S2 has the frequencies f1,.
This is a waveform of the input power that must be applied to the device under test A in order for the device under test A to output a power level within the standard at each point of fn. When the calculation of the waveform is completed, the controller 5 sends control data of the waveform obtained by correcting the ideal data f in FIG. 5 to the equalizer 2 (step S3).

Thereafter, when reading the actually measured output waveform c from the spectrum analyzer 3 (step S4), the controller 5 compares the previously stored ideal output waveform e with the actually measured output waveform c (step S5). Step S5
When the power level of the actually measured output waveform c falls within the standard at each point of the frequencies f1,..., Fn, the controller 5 ends the output control process.

When the power level is out of the standard in step S5, the controller 5 calculates each difference between the power level of the actually measured output waveform c and the power level of the ideal output waveform e at the point of the frequency outside the standard. (Step S6), and sends each difference to the equalizer 2 (Step S6).
7). The controller 5 operates until the actually measured output waveform c falls within the standard at all points of the frequencies f1,..., Fn.
Steps S6 and S7 are repeated. The controller 5 performs the output control process in this manner.

Next, the operation of this embodiment will be described. Connect the input side of the semiconductor device as the device under test A to the terminal 6A.
And the output side of the device under test A is attached to the terminal 6B. Before starting the measurement of the distortion characteristic, the distortion characteristic measuring apparatus performs a process for setting the output power of the device under test A within the standard. For this purpose, the signal sources SG1,.
Signals having frequencies f1,..., Fn and the same output power are sent to the multiplexer 1. The multiplexer 1 is
These signals are combined and sent to the equalizer 2.

On the other hand, when the measurement starts, the controller 5
Starts the output control process and generates control data using the measurement data d and the ideal output waveform e fetched from the reading unit 4 in steps S1 and S2 of the output control process. Then, the controller 5 sends the control data to the equalizer 2 in step S3.

Upon receiving the control data from the controller 5, the equalizer 2 controls the slope attenuator 2B to adjust the power level of the signal from the multiplexer 1 at each point of the frequencies f1,. The waveform data a of FIG. 2 is generated. Thereafter, the equalizer 2 adds a signal whose power level has been adjusted using the waveform data a, that is, a signal having a power level waveform b to the device under test A. The device under test A amplifies and outputs a signal from the equalizer 2.

[0027] The spectrum analyzer 3
Upon receiving the output signal from the controller, the spectrum of the output power of the signal is analyzed to generate an actually measured output waveform c of the output power as shown in FIG. The spectrum analyzer 3 sends the generated measured output waveform c to the controller 5. When reading the measured output waveform c from the spectrum analyzer 3 in step S4 of the output control process, the controller 5 compares the measured output waveform c with the ideal output waveform e in step S5. When the power level of the actually measured output waveform c falls within the standard at each point of the frequencies f1,..., Fn, the controller 5 ends the output control process.

If a point occurs where the power level becomes out of the standard, the controller 5 proceeds to steps S6 and S7.
Thus, at the points of each frequency outside the standard, the difference between the power level of the actually measured output waveform c and the power level of the ideal output waveform e is calculated, and each difference is sent to the equalizer 2. When the equalizer 2 receives the differences, the equalizer 2 controls the slope attenuator 2B based on the differences to change the power level of the signal to be transmitted to the device under test A at a corresponding frequency point. Thereby, the equalizer 2 corrects the waveform data a. Then, the equalizer 2 adds the power waveform b generated using the corrected waveform data a to the device under test A. Thereafter, the controller 5 receives the actually measured output waveform c via the device under test A and the spectrum analyzer 3, and the power level of the actually measured output waveform c falls within the standard at each point of the frequencies f1,..., Fn. Until,
Steps S6 and S7 of the output control process are repeated.

As described above, according to this embodiment, it is not necessary to sequentially adjust the outputs from the signal sources SG1,..., SGn in the output control processing.
At each point of the frequency of the signal from, the processing time for making the power within the standard can be performed at high speed. In particular, even when the number of signal sources increases, the processing time can be made substantially constant as shown by the line 101 in the graph of FIG.
Further, since the reading unit 4 stores the measurement data d of each DUT, when the DUT A is exchanged, it is sufficient to read new measurement data of the DUT. Changes can be made in a short time.

Second Embodiment FIG. 8 is a block diagram schematically showing a configuration of a distortion characteristic measuring device according to a second embodiment of the present invention, and FIG. 9 shows processing of a controller of the distortion characteristic measuring device. It is a flowchart. As shown in FIG. 8, the distortion characteristic measuring device includes signal sources SG1,..., SGn, a multiplexer 1, an equalizer 2, a spectrum analyzer 3, a reading unit 4, terminals 6A and 6B,
Directional coupler 11, switch 12, and controller 13
Is configured. 8, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and the description thereof will be omitted.

The directional coupler 11 is inserted between the equalizer 2 and the terminal 6A. The directional coupler 11 applies the signal from the equalizer 2 to the device under test A via the terminal 6A and distributes the signal to the switch 12. The switch 12 is connected between the terminal 6B and the spectrum analyzer 3. The switch 12 is connected to the terminal 1
The signal from the directional coupler 11 or the signal from the device under test A is sent to the spectrum analyzer 3 by switching between the terminal 2A and the terminal 12B.

The controller 13 stores the ideal output waveform e shown in FIG. 5, similarly to the controller 5 of FIG. The controller 13 uses the ideal output waveform e
The output control process shown in FIG. 9 is performed. When this process is started, the controller 5 takes in the measurement data d from the reading unit 4 (Step S11). After step S11, the controller 13 switches the switch 12 to send a signal from the equalizer 2 to the spectrum analyzer 3 (step S12). Thereafter, the controller 13 reads the output waveform from the spectrum analyzer 3, that is, the waveform of the output power of the signal output from the equalizer 2. At this time, since the control data has not been sent to the equalizer 2, the controller 13 confirms the state of the equalizer 2 by using the fact that the power levels of the signals from the multiplexer 1 are the same (step S13).

Thereafter, based on the state of the equalizer 2, the controller 13 outputs the ideal output waveform e stored in advance.
Based on the measurement data d received from the reading unit 4 in step S1, the power levels at the respective points of the frequencies f1,..., Fn are checked, and the waveform of the input power required for the device A is calculated (step S14). Controller 5
When the calculation of the waveform is completed, the control data of the waveform is sent to the equalizer 2 (step S15). Step S15
After that, since the switch 12 has selected the terminal 12A in step S12, the controller 13 checks the signal monitored from the equalizer 2 and determines whether the waveform of the signal is the same as that calculated in step S14. It is checked whether it is (step S16). If the waveform monitored in step S16 is not the calculated waveform, the controller 13 repeats the processing in steps S13 to S15.

When the monitored waveform is calculated in step S16, the controller 13 controls the switch 12 to select the terminal 12A, and connects the terminal 6B to the spectrum analyzer 3 (step S1).
7). When the connection in step S17 is completed, the controller 13 performs the processes in steps S18 to S21, which are the same processes as those in steps S4 to S7 in FIG. Controller 1
3 performs output control processing in this way.

With this configuration, the controller 13 monitors the equalizer 2 in the processing of steps S12 to S17 and resets the equalizer 2 as necessary.
That is, the controller 13 directly checks the waveform of the output power of the equalizer 2 and sets the equalizer 2, so that
The power of the signal applied to the device under test A can be set accurately. As described above, the first and second embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the above-described embodiments, and a design within a range not departing from the gist of the present invention. Modifications and the like are included in the present invention. For example, although the measurement data is stored in the reading unit 4, the measurement data of the measured object may be input each time the measured object is changed.

[0036]

As described above, according to the distortion characteristic measuring apparatus of the first and second aspects, the equalizer is used to control the power at each point of n frequencies of the signal from the multiplexer. Adjust the level. This makes it possible to perform the processing for setting the output power of the signal from the device under test in a shorter time than in the related art in which the n signal sources are sequentially set.

According to the distortion characteristic measuring device of the third aspect, since the reading section stores the amplitude characteristics of the plurality of DUTs, the DUT can be easily changed. According to the distortion characteristic measuring device of the fourth aspect, the amplitude characteristic is obtained by using the network analyzer, so that the amplitude characteristic of the device under test can be obtained accurately and easily.

According to the distortion characteristic measuring apparatus of the fifth aspect, since the power level is adjusted using the slope attenuator, the control by the controller can be simplified. According to the distortion characteristic measuring apparatus according to claim 6, the controller directly monitors the waveform of the output power from the equalizer by the directional coupler and the switch, so that the signal applied to the device under test is The power level can be set accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of a distortion characteristic measuring device according to a first embodiment of the present invention.

FIG. 2 is a waveform chart showing waveform data of an equalizer of the distortion characteristic measuring device.

FIG. 3 is a waveform chart showing an actually measured output waveform from a spectrum analyzer of the distortion characteristic measuring apparatus.

FIG. 4 is a waveform chart showing measurement data from a reading section of the distortion characteristic measuring device.

FIG. 5 is a waveform diagram showing an ideal output waveform stored by a controller of the distortion characteristic measuring device.

FIG. 6 is a flowchart showing a process of a controller of the distortion characteristic measuring device.

FIG. 7 is a graph showing a processing time by the distortion characteristic measuring device.

FIG. 8 is a block diagram schematically showing a configuration of a distortion characteristic measuring device according to a second embodiment of the present invention.

FIG. 9 is a flowchart showing a process of a controller of the distortion characteristic measuring device.

FIG. 10 is a block diagram showing a conventional distortion characteristic measuring device.

FIG. 11 is a flowchart showing processing of a controller of the distortion characteristic measuring device.

FIG. 12 is a graph showing a processing time by the distortion characteristic measuring device.

[Explanation of symbols]

 Reference Signs List 1 multiplexer 2 equalizer 2A amplifier 2B slope attenuator 3 spectrum analyzer 4 reading unit 5 controller 6A terminal (first terminal) 6B terminal (second terminal) SG1, ..., SGn signal source

Claims (6)

(57) [Claims] 1. A first terminal and a second terminal to which an input side and an output side of a device under test to be measured for distortion are respectively attached, and n (n is an arbitrary natural number, the same applies hereinafter) frequencies N signal sources each outputting a signal of the following, a multiplexer for multiplexing signals from the n signal sources, and a power level of a signal from the multiplexer is adjusted at each of the frequencies. An equalizer for adding a signal whose level has been adjusted to the first terminal, a spectrum analyzer for examining an output waveform of output power from the second terminal, an ideal waveform stored in advance,
From the previously measured amplitude characteristics of the device under test, control data for converting the output waveform into the ideal waveform is generated and sent to the equalizer, and thereafter, the analysis waveform from the spectrum analyzer and the ideal waveform And a control unit for sending a difference between the analysis waveform and the ideal waveform to the equalizer, wherein the equalizer, upon receiving the control data, adjusts a power level of each frequency based on the control data. Receiving the difference and adjusting a power level of a corresponding frequency. 2. The control section generates control data for converting the output waveform into the ideal waveform from a reading section that outputs the amplitude characteristic, the amplitude characteristic from the reading section, and the ideal waveform. A controller that compares the analysis waveform from the spectrum analyzer with the ideal waveform and sends a difference between the analysis waveform and the ideal waveform to the equalizer. The distortion characteristic measuring device according to claim 1, wherein 3. The distortion characteristic measuring apparatus according to claim 2, wherein the reading section stores amplitude characteristics of a plurality of DUTs. 4. The distortion characteristic measuring device according to claim 1, wherein the amplitude characteristic is measured using a network analyzer. 5. An equalizer comprising: an amplifier for amplifying a signal from the multiplexer in a frequency band including the range of the n frequencies; and receiving the control data, the frequency equalizer based on the control data. 5. The distortion characteristic measuring device according to claim 1, further comprising a slope attenuator that adjusts the power level by changing a degree of attenuation. 6. The control unit includes: a directional coupler inserted between the equalizer and the first terminal;
And a switch for transmitting output power from the second terminal or output power from the directional coupler to the spectrum analyzer under the control of the controller. The controller switches the switch, receives the waveform of the output power from the directional coupler from the spectrum analyzer, checks the current characteristics of the equalizer, and reads the current characteristics and the reading. The control data is generated from the amplitude characteristic from the section and the ideal waveform and sent to the equalizer. Thereafter, the analysis waveform from the spectrum analyzer is compared with the ideal waveform, and the analysis waveform and the ideal waveform are compared. 6. The distortion characteristic measuring apparatus according to claim 2, wherein a difference between the distortion characteristic and the difference is sent to the equalizer.