JP7165763B2 - Signal generator and its attenuation correction method - Google Patents

Description

The present invention relates to a signal generator that generates a modulated wave in a desired frequency band.

As a signal generator for generating a modulated wave in a desired frequency band, for example, there is a signal generator that generates a modulated wave in a desired frequency band by frequency-converting an intermediate frequency signal generated by an arbitrary signal generator using a mixer or the like. Are known.

Such a signal generator is incorporated in, for example, a mobile terminal testing device for testing mobile communication terminals, and generates and outputs a signal for testing.

Patent Document 1 discloses a storage device that stores the relationship between the number of transmission slots, the attenuation setting value, and the terminal voltage control value, and an attenuation that controls the attenuation based on the attenuation setting value selected based on the number of transmission slots. and an amplifier that controls the transmission power of a transmission signal based on a terminal voltage control value selected based on the number of transmission slots, and uses the ambient temperature of the amplifier to adjust the attenuation setting value and the terminal voltage control value. Weighting is described.

As described above, some devices using semiconductor components such as attenuators and amplifiers have characteristics that change depending on the temperature.

Japanese Patent Application Laid-Open No. 2006-80992

Devices whose characteristics change with temperature are equipped with a detector or the like for detecting the signal level in order to adjust the change in characteristics. In detectors for such applications, there is a detector that outputs a voltage corresponding to the signal level. Since the amount of adjustment is not known, it took time for adjustment.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a signal generator capable of correcting an output signal in a short period of time even if it has a level detector that cannot output a signal level value.

A signal generator according to the present invention comprises a signal generator that generates a test signal, a variable attenuator that attenuates the signal generated by the signal generator, and a level of the signal attenuated by the variable attenuator. and a level detector for outputting a voltage corresponding to the level of the signal, the gradient of the characteristic of the level detector , which is the amount of change in the output voltage with respect to the amount of change in the level of the signal, is stored. causing the signal generating section to generate a signal of a predetermined level, and outputting the level detecting section when the voltage output from the level detecting section is not a predetermined voltage corresponding to the level of the signal to be adjusted. a control unit for determining a corrected attenuation amount of the variable attenuator for making the voltage output from the level detection unit the predetermined voltage, based on the difference between the voltage output from the level detection unit and the predetermined voltage and the slope of the characteristic of the level detection unit and

With this configuration, the signal generator generates a signal of a predetermined level, and when the voltage output from the level detector is not the predetermined voltage corresponding to the level of the signal to be adjusted, the level detector outputs The corrected attenuation amount of the variable attenuator is obtained from the difference between the voltage and the predetermined voltage and the slope of the characteristic of the level detection section. Therefore, even if a level detector that cannot output a signal level value is provided, the output signal can be corrected in a short time.

Further, in the signal generator of the present invention, the controller stores the slope of the characteristic of the level detector for each frequency of the signal to be generated.

With this configuration, the slope of the characteristic of the level detector is changed for each frequency of the signal to be generated, and the corrected attenuation amount of the variable attenuator is obtained. Therefore, the correction attenuation amount of the variable attenuator can be obtained with high accuracy, and the output signal can be corrected in a short time.

Further, an attenuation amount correction method of the present invention includes a signal generation section that generates a test signal, a variable attenuator that attenuates the signal generated by the signal generation section, and a level of the signal attenuated by the variable attenuator. and a control unit that stores the slope of the characteristics of the level detection unit, which is the amount of change in the output voltage with respect to the amount of change in the level of the signal. A method for correcting an attenuation amount of a signal generator, comprising the steps of: generating a signal of a predetermined level by the signal generating section ; When the predetermined voltage does not correspond to the level of the target signal, the difference between the voltage output from the level detection section and the predetermined voltage and the slope of the characteristic of the level detection section cause the level detection section to The step of obtaining a corrected attenuation amount of the variable attenuator for setting the output voltage to the predetermined voltage, and the step of correcting the attenuation amount of the variable attenuator based on the obtained corrected attenuation amount.

With this configuration, the signal generator generates a signal of a predetermined level, and when the voltage output from the level detector is not the predetermined voltage corresponding to the level of the signal to be adjusted, the level detector outputs The corrected attenuation amount of the variable attenuator is obtained from the difference between the voltage and the predetermined voltage and the slope of the characteristic of the level detection section. Therefore, even if a level detector that cannot output a signal level value is provided, the output signal can be corrected in a short time.

INDUSTRIAL APPLICABILITY The present invention can provide a signal generator capable of correcting an output signal in a short period of time even if it has a level detector that cannot output a signal level value.

FIG. 1 is a block diagram of a signal generator according to one embodiment of the present invention. FIG. 2 is a flowchart for explaining the procedure of attenuation amount correction processing of the signal generator according to one embodiment of the present invention.

Hereinafter, signal generators according to embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1, a signal generator 1 according to an embodiment of the present invention includes a signal generator 10 that generates a test signal, a variable attenuator 11 that attenuates the test signal generated by the signal generator 10, A level detector 12 for detecting the level of the test signal attenuated by the variable attenuator 11, an output port 13 for outputting the test signal attenuated by the variable attenuator 11, and a temperature around the variable attenuator 11 are measured. A temperature detection unit 14 for detecting temperature, a user interface unit 15 for accepting a user's operation and providing information to the user, and a control unit 16 for controlling each part of the device to execute processing as the signal generation device 1. consists of

The signal generation unit 10 is configured by a signal generator that generates test signals having the intensity and frequency set by the control unit 16 . The variable attenuator 11 is configured by, for example, a voltage control type variable attenuator. The variable attenuator 11 may be a digital control type variable attenuator.

The level detector 12 detects the level of the test signal attenuated by the variable attenuator 11 and outputs it to the controller 16 . The level detection section 12 outputs, for example, a voltage value corresponding to the detected level to the control section 16 . The temperature detector 14 detects the temperature around the variable attenuator 11 and outputs it to the controller 16 .

The user interface unit 15 includes an input unit that receives an operation input from a user, and a display unit that displays a screen for setting parameters of test signals to be generated, various messages, and the like. The input unit is composed of a touch pad, keyboard, push buttons, rotary knob, and the like. The display unit is configured by a liquid crystal display device or the like. The input unit can also receive input by remote operation.

The control unit 16 is configured by a computer unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk device, and an input/output port (not shown).

The ROM and hard disk device of the computer unit store programs for causing the computer unit to function as the control section 16 along with various control constants, various maps, and the like. That is, the computer unit functions as the control unit 16 by the CPU executing programs stored in the ROM and the hard disk device. The hard disk device may be a CF (Compact Flash) card based on flash memory.

The input/output ports of the controller 16 are connected to the signal generator 10, the variable attenuator 11, the level detector 12, the temperature detector 14, and the user interface 15, so that the controller 16 and each part can transmit and receive signals. It has become.

In this embodiment, the variable attenuator 11 has nonlinear characteristics. Also, the variable attenuator 11 has different characteristics depending on the frequency of the signal to be attenuated.

Also, the characteristics of the variable attenuator 11 change depending on the temperature of the variable attenuator 11 . The hard disk device of the control unit 16 stores, for example, the characteristics of the variable attenuator 11 for each predetermined temperature. The control unit 16 obtains the characteristics of the variable attenuator 11 based on the temperature around the variable attenuator 11 detected by the temperature detection unit 14 .

Based on the obtained characteristics, the control unit 16 obtains a control voltage, which is a control parameter of the variable attenuator 11, such that a predetermined attenuation amount, for example, 10 dB, is obtained, and sets the attenuation amount of the variable attenuator 11 with the control voltage. do.

Also, the level detector 12 outputs a voltage value corresponding to the detected signal level. Therefore, although the difference from the voltage value corresponding to the target signal level is known, it is not known to what extent the difference corresponds to the signal level, and adjustment takes time.

In the hard disk device of the control unit 16, the slope of the characteristic of the level detection unit 12 (the amount of change in the output voltage value with respect to the amount of change in the signal level), for example, the amount of change in the output voltage value when the signal level changes by 1 dB is stored. remembered. The hard disk device of the control unit 16 stores, for example, the slope of the characteristic for each frequency of the signal to be generated.

The control unit 16 causes the signal generation unit 10 to generate a signal of a predetermined level. Corrects the attenuation due to

The control section 16 obtains the correction attenuation amount of the variable attenuator 11 from the difference between the output voltage value of the level detection section 12 and a predetermined voltage value and the slope of the characteristic of the level detection section 12 .

The control unit 16 corrects the attenuation amount of the variable attenuator 11 based on the calculated corrected attenuation amount. Then, the output voltage value of the level detection section 12 is obtained again, and the process is repeated until the output voltage value of the level detection section 12 reaches a predetermined voltage value.

Attenuation amount correction processing by the signal generator according to the present embodiment configured as described above will be described with reference to FIG. Note that the attenuation correction process described below is executed when the output level correction function is selected by operating the user interface unit 15 .

In step S1, the control section 16 sets the control voltage of the variable attenuator 11 to a predetermined voltage, and causes the signal generation section 10 to generate a signal of a predetermined level. After executing the process of step S1, the control unit 16 executes the process of step S2.

In step S<b>2 , the control section 16 acquires the output voltage of the level detection section 12 . After executing the process of step S2, the control unit 16 executes the process of step S3.

In step S3, the control section 16 determines whether or not the voltage obtained from the level detection section 12 is equal to a predetermined voltage.

When determining that the voltage obtained from the level detection unit 12 is equal to the predetermined voltage, the control unit 16 ends the attenuation amount correction processing. When determining that the voltage acquired from the level detection unit 12 is not equal to the predetermined voltage, the control unit 16 executes the process of step S4.

In step S<b>4 , the control section 16 obtains the corrected attenuation amount of the variable attenuator 11 from the difference between the voltage acquired from the level detection section 12 and the predetermined voltage and the slope of the characteristic of the level detection section 12 . After executing the process of step S4, the control unit 16 executes the process of step S5.

In step S5, the control unit 16 corrects the attenuation amount of the variable attenuator 11 with the obtained correction attenuation amount. After executing the process of step S5, the control unit 16 executes the process of step S2.

As described above, in the above-described embodiment, the control unit 16 stores the slope of the characteristic of the level detection unit 12, the difference between the voltage acquired from the level detection unit 12 and the predetermined voltage, and the level detection unit 12 The correction attenuation amount of the variable attenuator 11 is obtained from the slope of the characteristic of .

Thereby, the corrected attenuation amount of the variable attenuator 11 is obtained from the difference between the voltage acquired from the level detection section 12 and the predetermined voltage. Therefore, even if a level detector that cannot output a signal level value is provided, the output signal can be corrected in a short time.

Also, the control unit 16 stores the slope of the characteristic of the level detection unit 12 for each frequency of the signal to be generated.

As a result, the slope of the characteristic of the level detector 12 is changed for each frequency of the signal to be generated, and the corrected attenuation amount of the variable attenuator 11 is obtained. Therefore, the correction attenuation amount of the variable attenuator 11 can be obtained with high accuracy, and the output signal can be corrected in a short time.

In this embodiment, the case where one output port 13 is provided is shown, but a configuration in which a plurality of output ports 13 are provided and each output port 13 is provided with a variable attenuator 11 and a level detection section 12 is also possible. , can be implemented in the same way, and the effect of shortening the time is enhanced.

In such a case, by storing the slope of the characteristic of each of the plurality of level detectors 12, the individual difference of the plurality of level detectors 12 can be absorbed, and the corrected attenuation amount of the variable attenuator 11 can be obtained with high accuracy. The output signal can be corrected in a short time.

Although embodiments of the present invention have been disclosed, it will be apparent that modifications may be made by those skilled in the art without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

1 signal generator 10 signal generator 11 variable attenuator 12 level detector 14 temperature detector 16 controller

Claims (3)

a signal generator (10) for generating a test signal;
a variable attenuator (11) for attenuating the signal generated by the signal generator; and a level detector (12) for detecting the level of the signal attenuated by the variable attenuator and outputting a corresponding voltage. A signal generator comprising
storing the slope of the characteristic of the level detection unit, which is the amount of change in the output voltage with respect to the amount of change in the level of the signal ;
When the signal generation unit generates a signal of a predetermined level and the voltage output from the level detection unit is not the predetermined voltage corresponding to the level of the signal to be adjusted,
Correction of the variable attenuator to set the voltage output from the level detection unit to the predetermined voltage based on the difference between the voltage output from the level detection unit and the predetermined voltage and the slope of the characteristic of the level detection unit. A signal generator comprising a controller (16) for obtaining an attenuation amount. 2. The signal generator according to claim 1, wherein the control section stores the slope of the characteristic of the level detection section for each frequency of the signal to be generated. A signal generator (10) that generates a test signal, a variable attenuator (11) that attenuates the signal generated by the signal generator, and a level of the signal attenuated by the variable attenuator that is detected and handled. and a control unit (16) storing the slope of the characteristics of the level detection unit, which is the amount of change in the output voltage with respect to the amount of change in the level of the signal. An attenuation correction method for a signal generator comprising
generating a signal of a predetermined level by the signal generator;
When the voltage output from the level detection unit for the attenuated signal of the predetermined level is not the predetermined voltage corresponding to the level of the signal to be adjusted, the voltage output from the level detection unit and the predetermined level are not equal to each other. a step of obtaining a corrected attenuation amount of the variable attenuator for setting the voltage output from the level detection unit to the predetermined voltage based on the difference between the voltage and the slope of the characteristic of the level detection unit;
and a step of correcting the attenuation of the variable attenuator with the obtained corrected attenuation.

Images