Signal generation apparatus and signal generation method
An object of the present disclosure is to prevent an output level of an analog signal from exceeding a predetermined upper limit value, in a module that adjusts a level of the analog signal. According to the present disclosure, there is provided a signal generation apparatus including an RF base module ( 12 ) that converts a digital base band signal for testing into an intermediate frequency (IF) signal and outputs the IF signal, and a control unit ( 18 ), in which the RF base module is connected to an RF converter ( 20 ) which outputs an analog RF signal obtained by frequency-converting the IF signal, and the control unit clips the IF signal output from the RF base module based on an output level of the analog RF signal output from the RF converter.
1. A signal generation apparatus comprising:
a radio frequency (RF) converter configured to convert an analog signal for testing into an analog RF signal, the RF converter comprising:
a power amplifier configured to amplify the analog signal for testing, and
a switch configured to selectively switch between a first path and a second path, the first path passing through the power amplifier and the second path bypassing the power amplifier;
at least one controller configured to adjust an amplitude of a frequency included in the analog RF signal; and
a temperature sensor configured to measure a temperature inside the RF converter,
wherein the at least one controller is further configured to:
control an input level of the analog signal for testing such that the input level does not exceed a predetermined upper limit value;
connect the switch to the first path, completion of the adjustment of the amplitude being a trigger for connecting the switch, and
switch the switch from the first path to the second path based on a temperature fluctuation detected by the temperature sensor.
2. The signal generation apparatus according to claim 1 ,
wherein the RF converter:
is connected to a signal source configured to generate the analog signal for testing by using an RF cable, and
further comprises a cable sensor configured to detect disconnection of the RF cable, and
wherein when the cable sensor detects the disconnection of the RF cable, the at least one controller is configured to switch the switch from the first path to the second path.
3. The signal generation apparatus according to claim 2 , further comprising:
an activation sensor configured to detect activation of the signal source,
wherein when the activation sensor detects the activation of the signal source, the at least one controller is configured to connect the switch to the second path.
4. A signal generation apparatus comprising:
a radio frequency (RF) converter configured to convert an analog signal for testing into an analog RF signal;
at least one controller configured to control an output level of the analog signal such that the output level does not exceed a predetermined upper limit value;
an RF base module configured to convert a digital base band signal for testing into an intermediate frequency (IF) signal and to output the IF signal to the RF converter as the analog signal for testing; and
a reference table that associates a clipping amount with the output level of the analog RF signal,
wherein the RF converter is configured to convert the analog signal for testing into the analog RF signal by frequency-converting the IF signal, and
wherein the at least one controller is further configured to clip the IF signal output from the RF base module based on the output level of the analog RF signal output from the RF converter such that:
when the output level of the analog RF signal is set, the at least one controller is further configured to calculate a threshold value of clipping power based on the reference table, and
when a power of the digital base band signal exceeds the threshold value, the RF base module is configured to clip the IF signal according to the clipping amount in the reference table.
5. The signal generation apparatus according to claim 4 , further comprising:
a base band module configured to generate the digital base band signal and to output the digital base band signal to the RF base module.
6. The signal generation apparatus according to claim 4 , wherein the RF converter includes a power amplifier, and a switch that switches between a path passing through the power amplifier and a path bypassing the power amplifier.
7. The signal generation apparatus according to claim 5 , wherein the RF converter includes a power amplifier, and a switch that switches between a path passing through the power amplifier and a path bypassing the power amplifier.
8. A signal generation method using a signal generation apparatus comprising a radio frequency (RF) converter configured to convert an analog signal for testing into an analog RF signal, wherein the RF converter comprises: a power amplifier configured to amplify the analog signal, and a switch that-configured to selectively switch between a first path and a second path, the first path passing through the power amplifier and the second path bypassing the power amplifier, the method comprising:
controlling an output level of the analog signal such that the output level does not exceed a predetermined upper limit value; and
switching the switch from the first path to the second path based on temperature fluctuations in the RF converter, disconnection of an RF cable that inputs the analog signal for testing to the RF converter, or activation of a signal source that generates the analog signal for testing.
9. The signal generation method according to claim 8 ,
wherein the signal generation apparatus further comprises:
an RF base module that is configured to convert a digital base band signal for testing into an intermediate frequency (IF) signal and to output the IF signal as the analog signal for testing, and
a controller, and
wherein the method further comprises clipping the IF signal based on an output level of the analog RF signal output from the RF converter.