| 摘要 |
PROBLEM TO BE SOLVED: To provide a system for measuring a full spectrum of a modulated output signal provided by a device under test DUT.SOLUTION: The system includes a signal generating device 112 that provides an RF stimulus signal to the DUT, and generates a trigger signal, where the DUT outputs the modulated output signal in response. A receiver 120, having an intermediate frequency IF bandwidth less than a total bandwidth of the modulated output signal, includes mixers 121-123, an analog-to-digital converter ADC triggered by the trigger signal, and a local oscillator LO that consecutively generates multiple LO signals having different LO frequencies. A harmonic phase reference HPR generator 130 generates a repetitive HPR signal having an HPR bandwidth wider than the total bandwidth of the modulated output signal and a modulation repetition rate being the same as that of the RF stimulus signal. The mixers consecutively mix the LO signals with the HPR signal and the modulated output signal to provide IF signals input to channels CH0 to CH2 of the ADC, the IF signals forming ADC data records that capture the full spectrum of the modulated output signal.SELECTED DRAWING: Figure 1 |
