High-frequency method and apparatus for measuring an amplifier

1. A high-frequency measurement method for measuring an amplifier or a semiconductor amplifying element as a device under test, the high-frequency measurement method comprising:

generating a test signal, the test signal being a sine-wave signal having a predetermined frequency, in which a period during which a power level is at a first power level whose length is equivalent to a period during which an input signal intended for the device under test is at the first power level, and a period during which the power level is at a second power level lower than the first power level are periodically repeated;

inputting the test signal to the device under test as an input signal; and

measuring a difference between an output signal of the device under test and an ideal value of the output signal;

wherein the ideal value is generated based on the test signal.

2. The high-frequency measurement method according to claim 1 , wherein the difference is a difference relating to a time response or a frequency response of the output signal.

3. The high-frequency measurement method according to claim 1 , wherein the difference is a difference between the output signal and the ideal value relating to at least one of a power waveform, a waveform distortion, a phase rotation amount, and a transmission delay of the output signal.

4. The high-frequency measurement method according to claim 1 , wherein the amplifier or the semiconductor amplifying element is composed of a compound semiconductor transistor.

5. A high-frequency measurement method for measuring a compound semiconductor transistor as a device under test, the high-frequency measurement method comprising:

generating a test signal, the test signal being a sine-wave signal having a predetermined frequency, in which a period during which a power level is at a first power level whose length is equivalent to a period during which an input signal intended for the device under test is at the first power level, and a period during which the power level is at a second power level lower than the first power level are periodically repeated;

inputting the test signal to the device under test as an input signal; and

measuring, based on an output signal of the device under test, a transient response in gain variation of the device under test.

6. A high-frequency measurement apparatus comprising:

a signal generator configured to output a test signal, the test signal being a sine-wave signal having a predetermined frequency, in which a period during which a power level is at a first power level whose length is equivalent to a period during which an input signal intended for the device under test is at the first power level, and a period during which the power level is at a second power level lower than the first power level are periodically repeated; and

a measuring instrument configured to measure a difference between an output signal of a device under test and an ideal value of the output signal;

wherein the ideal value is generated based on the test signal.

7. The high-frequency measurement apparatus according to claim 6 , wherein

the signal generator comprises:

a first signal generator configured to output a first sine-wave signal having the first power level;

a second signal generator configured to output a second sine-wave signal having the second power level; and

a combiner configured to combine the first sine-wave signal and the second sine-wave signal to output the test signal.