Signal generation apparatus and signal generation method

Abstract

To provide a signal generation device and a signal generation method thereof, the signal generation device having a function of preventing the power of an analog RF signal which is output by a RF converter from exceeding the rating of an RF amplifier and a function of checking whether or not the RF converter and the RF amplifier are connected to each other via an RF cable.SOLUTION: In a signal generation device according to the present invention, a control performed by a control unit 11 includes: adjusting an output of an RF converter 2 based on a detected voltage which is output by a detector 9 when the RF converter 2 outputs an analog RF signal; and determining whether or not the RF converter 2 and an RF amplifier 3 are connected to each other based on a change in the detected voltage when an attenuation amount of a variable attenuator 7 is changed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a signal generation device for generating a test signal and a signal generation method thereof.

Background Art

[0002] A signal generation device for generating a test signal for testing a mobile communication device has been proposed (see, for example, Patent Document 1). The signal generation device of Patent Document 1 includes an RF converter that converts a test analog signal into a radio frequency to obtain an analog RF (Radio Frequency) signal, amplifies and power-adjusts the analog RF signal, and outputs it from an antenna. And in Patent Document 1, a method for preventing the output power of the analog RF signal in the RF converter from exceeding a predetermined upper limit value is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Depending on the test of the mobile communication device, an RF amplifier for amplifying the output of the RF converter may be arranged after the signal generation device disclosed in Patent Document 1 and before the antenna. In such a configuration, the following two problems exist. (Problem 1) The power of the analog RF signal output by the signal generation device varies due to disturbances such as temperature. It is necessary to avoid an analog RF signal with a power exceeding the rating of the RF amplifier from being input to the RF amplifier. However, the signal generation device of Patent Document 1 has a problem that it is difficult to confirm the power of the output analog RF signal. (Problem 2) The RF converter and the RF amplifier are connected by an RF cable, and the analog RF signal is input from the RF converter to the RF amplifier via the RF cable. However, the signal generator of Patent Document 1 does not have a means for confirming whether the RF converter and the RF amplifier are connected by an RF cable, and there is a problem that it is difficult to determine whether the test of the mobile communication device is being correctly performed.

[0005] Therefore, in order to solve the above two problems, an object of the present invention is to provide a signal generator and a signal generation method thereof, which have a function of preventing the power of the analog RF signal output by the RF converter from exceeding the rating of the RF amplifier, and a function of confirming that the RF converter and the RF amplifier are connected by an RF cable.

Means for Solving the Problems

[0006] In order to achieve the above object, the signal generator according to the present invention monitors the output value (detected voltage) of the detector included in the RF amplifier, and monitors the behavior of the detected voltage when the amplification amount of the analog RF signal in the RF amplifier is changed.

[0007] Specifically, the signal generator according to claim 1 of the present invention an RF converter (2) that modulates a test analog signal to output an analog RF signal, a variable attenuator (7) that adjusts the amplitude of the analog RF signal by an attenuation amount, and an RF amplifier (3) having a detector (9) that detects the analog RF signal whose amplitude has been adjusted, a control unit (11) that controls the RF converter and the RF amplifier, is a signal generator comprising the control performed by the control unit is adjusting the output of the RF converter based on the detected voltage output by the detector when the RF converter outputs the analog RF signal, and Determining the presence or absence of a connection between the RF converter and the RF amplifier based on a change in the detected voltage when the attenuation amount of the variable attenuator is changed is characterized by.

[0008] The present signal generation device prevents the power of the analog RF signal output by the RF converter from exceeding the rating of the RF amplifier by adjusting the power of the analog RF signal based on the detected voltage of a detector included in the RF amplifier. Further, the present signal generation device determines whether the RF converter and the RF amplifier are connected by an RF cable based on the behavior of the detected voltage when the amplification amount of the analog RF signal in the RF amplifier is changed.

[0009] Therefore, the present invention can provide a signal generation device having a function of preventing the power of the analog RF signal output by the RF converter from exceeding the rating of the RF amplifier and a function of confirming that the RF converter and the RF amplifier are connected by an RF cable.

[0010] The control unit of the signal generation device according to claim 2 of the present invention Adjusting the output of the RF converter includes performing a comparison step of comparing the detected voltage output by the detector with a first threshold value when the RF converter outputs the analog RF signal, and when the detected voltage exceeds the first threshold value, reducing the power of the analog RF signal by a certain amount and outputting it to the RF converter, and performing the comparison step again. is characterized by.

[0011] The present signal generation device operates as described above to prevent the power of the analog RF signal from exceeding the rating of the RF amplifier.

[0012] The control unit of the signal generation device according to claim 3 of the present invention Determining the presence or absence of a connection between the RF converter and the RF amplifier When the detected voltage does not exceed the first threshold value, using the detected voltage as a reference value, calculate the differential voltage between the detected voltage output by the detector when the attenuation amount of the variable attenuator is decreased and the reference value. When the differential voltage exceeds a second threshold value, determine that the RF converter and the RF amplifier are connected. When the differential voltage does not exceed the second threshold value, repeat the reconfirmation step of further decreasing the attenuation amount of the variable attenuator and comparing the differential voltage with the second threshold value. When the differential voltage exceeds the second threshold value in the reconfirmation step, determine that the RF converter and the RF amplifier are connected. When the differential voltage does not exceed the second threshold value even after the reconfirmation step is performed a predetermined number of times, determine that the RF converter and the RF amplifier are not connected. It is characterized by the above.

[0013] By operating as described above, this signal generation device determines whether the RF converter and the RF amplifier are connected by an RF cable.

[0014] The method according to claim 4 of the present invention is a signal generation method using the signal generation device according to claim 1, Perform a comparison step of comparing the detected voltage output by the detector with a first threshold value when the analog RF signal is output to the RF converter. When the detected voltage exceeds the first threshold value, reduce the power of the analog RF signal by a certain amount and output it to the RF converter, and perform the comparison step again. When the detected voltage does not exceed the first threshold value, using the detected voltage as a reference value, calculate the differential voltage between the detected voltage output by the detector when the attenuation amount of the variable attenuator is decreased and the reference value. When the differential voltage exceeds a second threshold value, determine that the RF converter and the RF amplifier are connected. When the differential voltage does not exceed the second threshold value, repeat the reconfirmation step of further decreasing the attenuation amount of the variable attenuator and comparing the differential voltage with the second threshold value. When the differential voltage exceeds the second threshold value in the reconfirmation step, determine that the RF converter and the RF amplifier are connected. When the differential voltage does not exceed the second threshold value even after performing the reconfirmation step a predetermined number of times, determine that the RF converter and the RF amplifier are not connected. is characterized by.

[0015] By this signal generation method, it is possible to prevent the power of the analog RF signal output by the RF converter from exceeding the rating of the RF amplifier by adjusting the power of the analog RF signal based on the detection voltage of the detector included in the RF amplifier. Also, by this signal generation method, it is possible to determine whether the RF converter and the RF amplifier are connected by an RF cable from the behavior of the detection voltage when the amplification amount of the analog RF signal in the RF amplifier is changed.

[0016] Therefore, the present invention can provide a signal generation method having a function of preventing the power of the analog RF signal output by the RF converter from exceeding the rating of the RF amplifier and a function of confirming that the RF converter and the RF amplifier are connected by an RF cable.

[0017] In addition, the above inventions can be combined as much as possible.

Effect of the Invention

[0018] The present invention can provide a signal generation device and a signal generation method having a function of preventing the power of the analog RF signal output by the RF converter from exceeding the rating of the RF amplifier and a function of confirming that the RF converter and the RF amplifier are connected by an RF cable.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. It should be noted that the present disclosure is not limited to the embodiments shown below. These examples are merely illustrative, and the present disclosure can be implemented in various modified forms based on the knowledge of those skilled in the art. In the present specification and drawings, components having the same reference numerals are assumed to be the same as each other.

[0021] FIG. 1 is a diagram for explaining the configuration of the signal generation device of the present embodiment. This signal generation device includes an RF converter 2 that modulates an analog signal for testing to output an analog RF signal, an RF amplifier 3 having a variable attenuator 7 that adjusts the amplitude of the analog RF signal by an attenuation amount, and a detector 9 that detects the analog RF signal whose amplitude has been adjusted, a control unit 11 that controls the RF converter 2 and the RF amplifier 3, and is a signal generation device comprising wherein the control performed by the control unit 11 is to adjust the output of the RF converter 2 based on the detection voltage output by the detector 9 when the RF converter 2 outputs the analog RF signal, and to determine the presence or absence of the connection between the RF converter 2 and the RF amplifier 3 based on the change in the detection voltage when the attenuation amount of the variable attenuator 7 is changed which is characterized by the above.

[0022] The signal source 1 includes a signal generation device 4 that generates a digital signal, and a DA converter 5 that converts the digital signal into an analog signal.

[0023] The RF converter 2 is a device that up-converts the frequency of an analog signal to a radio frequency to convert it into an analog RF signal, and has a variable attenuator 6 for adjusting the amplitude (power) of the analog RF signal. In addition, the RF converter 2 includes, among other things, a circuit with a function of up-converting the frequency (not shown). As an example, the frequency of the analog signal in the intermediate frequency band is 4.5 GHz, and the frequency of the analog RF signal is 24.25 GHz to 29.5 GHz.

[0024] The RF amplifier 3 amplifies the analog RF signal output by the RF converter 2 and outputs it from the antenna 13 as a test signal for performing a test on the mobile communication device. The RF amplifier 3 has a variable attenuator 7 for attenuating the power of the analog RF signal, a divider 8 for branching the analog RF signal with attenuated power, and a detector 9 for detecting the branched analog RF signal and outputting the amplitude (power) of the analog RF signal as a detection voltage. In addition, the RF amplifier 3 has, among other things, an amplifier at at least one of the front stage and the rear stage of the variable attenuator 7 (not shown).

[0025] In addition, the analog RF signal output from the RF converter 2 is input to the RF amplifier 3 via the RF cable 12.

[0026] Figure 2 is a flowchart for explaining how the control unit 11 controls the RF converter 2 and the RF amplifier 3. The control unit 11 performs a comparison step (steps S01 and S02) of comparing the detection voltage output by the detector 9 with a first threshold value when the analog RF signal is output to the RF converter 2, when the detection voltage exceeds the first threshold value (Yes in step S02), causes the RF converter 2 to output the analog RF signal with its power decreased by a certain amount (step S03), and performs the comparison step (steps S01 and S02) again, When the detected voltage does not exceed the first threshold value (No in step S02), the detected voltage is set as the reference value Vref, and when the attenuation amount of the variable attenuator 7 is decreased (raising the power of the analog RF signal), the differential voltage ΔV between the detected voltage output by the detector 9 and the reference value Vref is calculated (steps S04 and S05). When the differential voltage Vref exceeds the second threshold value (Yes in step S06), it is determined that the RF converter 2 and the RF amplifier 3 are connected by the RF cable 12 (step S07). When the differential voltage Vref does not exceed the second threshold value, the attenuation amount of the variable attenuator 7 is further decreased (raising the power of the analog RF signal further), and the reconfirmation process of comparing the differential voltage Vref with the second threshold value (steps S08 to S11) is repeated. When the differential voltage Vref exceeds the second threshold value in the reconfirmation process (Yes in step S10), it is determined that the RF converter 2 and the RF amplifier 3 are connected (step S07). When the differential voltage Vref does not exceed the second threshold value even after the reconfirmation process is performed a predetermined number of times (Yes in step S11), it is determined that the RF converter 2 and the RF amplifier 3 are not connected (step S12). It is characterized by the above.

[0027] Each step will be described below, including the specific values shown in FIG. 3. Due to temperature and aging, the power of the analog RF signal output by the RF converter 2 fluctuates. Therefore, first, the power of the analog RF signal output from the RF converter 2 is confirmed. In this process, the values in the first column of FIG. 3 are used. The control unit 11 adjusts the attenuation amount of the variable attenuator 7 and sets the signal amplification amount in the RF amplifier 3 to -23 dB. Step S01: An analog RF signal with an arbitrary power output from the RF converter 2 is attenuated by a predetermined attenuation amount by the variable attenuator 7 and detected by the detector 9. The detector 9 outputs a detected voltage corresponding to the power (amplitude) of the analog RF signal. This detected voltage is used as the reference value. Step S02: The amplifier of the RF amplifier 3 has a power rating for the input signal. If the power of the input analog RF signal is too large, it may exceed the amplifier's rating. Therefore, it is necessary to check whether the power of the analog RF signal output from the RF converter 2 is likely to exceed the amplifier's rating. The control unit 11 compares the reference value with the first threshold value. The first threshold value is set based on the rating of the amplifier of the RF amplifier 3. For example, the first threshold value is 3.2V. Step S03: When the reference value is higher than the first threshold value, the control unit 11 increases the attenuation amount of the variable attenuator 6 to reduce the power of the analog RF signal output from the RF converter 2. Then, steps S01 and S02 are performed again.

[0028] When the reference value is lower than or has become lower than the first threshold value, a connection determination between the RF converter 2 and the RF amplifier 3 is made. For example, assume that the reference value has become 0.789V as shown in the second column of FIG. 3. Step S04: To set the amplification amount of the RF amplifier 3 to -13dB described in the second column of FIG. 3, the control unit 11 adjusts the attenuation amount of the variable attenuator 7 (specifically, reduces the attenuation amount). Step S05: The control unit 11 calculates the differential voltage obtained by subtracting the reference value from the detection voltage output from the detector 9 at this time. For example, as shown in the second column of FIG. 3, if the detection voltage is 0.801V, the differential voltage is 0.801 - 0.789 = 0.012V. Step S06: The control unit 11 compares the differential voltage with the second threshold value. For example, the second threshold value is 0.6V. When the differential voltage is higher than the second threshold value in step S06, the control unit 11 determines that the RF converter 2 and the RF amplifier 3 are connected by the RF cable 12 (step S07). Step S08: On the other hand, when the differential voltage is lower than the second threshold value in step S06 (when the differential voltage is 0.012 V as in the above-described example), in order to set the amplification amount of the RF amplifier 3 to +12 dB described in the third column of FIG. 3, the control unit 11 adjusts the attenuation amount in the variable attenuator 7 (specifically, makes the attenuation amount even smaller). Step S09: The control unit 11 calculates a differential voltage obtained by subtracting a reference value from the detection voltage output from the detector 9 at this time. For example, as shown in the third column of FIG. 3, if the detection voltage is 2.272 V, the differential voltage is 2.272 - 0.789 = 1.483 V. Step S10: The control unit 11 compares the differential voltage with the second threshold value again. When the differential voltage is higher than the second threshold value in step S10 (when the differential voltage is 1.483 V as in the above-described example), the control unit 11 determines that the RF converter 2 and the RF amplifier 3 are connected by the RF cable 12 (step S07). On the other hand, when the differential voltage is lower than the second threshold value in step S10, the control unit 11 determines that the RF converter 2 and the RF amplifier 3 are not connected by the RF cable 12 (step S11). Note that instead of directly going to step S11, steps S08 to S10 may be repeated a predetermined number of times, and if the differential voltage is still lower than the second threshold value, step S11 may be performed.

[0029] Finally, the control unit 11 stores the results obtained in steps S07 and S11 in the storage unit 10 as connection information.

[0030] There are predetermined combinations for the number of repetitions of steps S08 to S10, the amount of adjustment of the attenuation amount in step S08, and the first threshold value and the second threshold value, and the control unit 11 selects and executes one of the combinations. This combination is a value corresponding to the characteristics of the RF amplifier 3.

[0031] [Effect] The loss of the RF cable 12 varies depending on its type and length. In the present invention, even when the path loss due to the RF cable 12 between the RF converter 2 and the RF amplifier 3 is unknown, an analog RF signal of any power from the RF converter 2 can be used to detect the connection between the RF converter 2 and the RF amplifier 3 without exceeding the rating of the RF amplifier 3.

Industrial Applicability

[0032] The present disclosure can be applied to the information and communication industry.

Explanation of Reference Numerals

[0033] 1: Signal source 2: RF converter 3: RF amplifier 4: Signal generator 5: DAC 6: Variable attenuator 7: Variable attenuator 8: Demultiplexer 9: Detector 10: Memory unit 11: Control unit 12: RF cable

Claims

1. An RF converter (2) that modulates a test analog signal to output an analog RF signal, an RF amplifier (3) having a variable attenuator (7) that adjusts the amplitude of the analog RF signal by an attenuation amount, and a detector (9) that detects the analog RF signal whose amplitude has been adjusted, a control unit (11) that controls the RF converter and the RF amplifier, A signal generation device comprising: The control performed by the control unit is adjusting the output of the RF converter based on the detection voltage output by the detector when the RF converter outputs the analog RF signal, and determining the presence or absence of connection between the RF converter and the RF amplifier based on the change in the detection voltage when the attenuation amount of the variable attenuator is changed A signal generation device characterized by the above.

2. The control unit Adjusting the output of the RF converter Performing a comparison step of comparing the detection voltage output by the detector when the RF converter outputs the analog RF signal with a first threshold value, and When the detection voltage exceeds the first threshold value, reducing the power of the analog RF signal by a certain amount and outputting it to the RF converter, and performing the comparison step again The signal generation device according to claim 1, characterized by the above.

3. The control unit Determining the presence or absence of connection between the RF converter and the RF amplifier When the detection voltage does not exceed the first threshold value, using the detection voltage as a reference value and calculating a differential voltage between the detection voltage output by the detector when the attenuation amount of the variable attenuator is decreased and the reference value, When the differential voltage exceeds a second threshold value, determining that the RF converter and the RF amplifier are connected, When the differential voltage does not exceed the second threshold value, further decreasing the attenuation amount of the variable attenuator and repeatedly performing a reconfirmation step of comparing the differential voltage with the second threshold value, In the reconfirmation step, when the differential voltage exceeds the second threshold value, determining that the RF converter and the RF amplifier are connected, When the differential voltage does not exceed the second threshold value even after performing the reconfirmation step a predetermined number of times, determining that the RF converter and the RF amplifier are not connected, The signal generation device according to claim 2, characterized by the above.

4. An RF converter (2) that modulates a test analog signal and outputs an analog RF signal, an RF amplifier (3) having a variable attenuator (7) that adjusts the amplitude of the analog RF signal and a detector (9) that detects the analog RF signal with the adjusted amplitude, A signal generation method performed by a signal generation device comprising: Performing a comparison step of comparing a detection voltage output by the detector with a first threshold value when the RF converter outputs the analog RF signal; When the detection voltage exceeds the first threshold value, causing the RF converter to output the analog RF signal with its power reduced by a certain amount and performing the comparison step again; When the detection voltage does not exceed the first threshold value, using the detection voltage as a reference value and calculating a differential voltage between the detection voltage output by the detector when the attenuation amount of the variable attenuator is decreased and the reference value; When the differential voltage exceeds a second threshold value, determining that the RF converter and the RF amplifier are connected; When the differential voltage does not exceed the second threshold value, repeatedly performing a reconfirmation step of further decreasing the attenuation amount of the variable attenuator and comparing the differential voltage with the second threshold value; In the reconfirmation step, when the differential voltage exceeds the second threshold value, determining that the RF converter and the RF amplifier are connected; When the differential voltage does not exceed the second threshold value even after the reconfirmation step is performed a predetermined number of times, determining that the RF converter and the RF amplifier are not connected; A signal generation method characterized by the above.

Images