System and method for measuring signal distortion

摘要

A system has an extended dynamic range for measuring distortion in an output signal of a device under test (DUT), the output signal having at least a first fundamental signal. The system includes a first combiner and a test receiver. The first combiner is configured to inject a first cancellation signal generated by a first signal source into the output signal from the DUT, at least one of a first magnitude and a first phase of the first cancellation signal being adjustable for suppressing the first fundamental signal. The test receiver is configured to receive and measure the output signal having the suppressed first fundamental signal.

主权项

1. A system having an extended dynamic range for measuring distortion in an output signal of a device under test (DUT), the output signal having at least a first fundamental signal, the system comprising:
a first coupler configured to inject a first cancellation signal generated by a first signal source into the output signal from the DUT, at least one of a first magnitude and a first phase of the first cancellation signal being adjustable for suppressing the first fundamental signal; a test receiver configured to receive and measure the output signal having the suppressed first fundamental signal; another test receiver configured to receive the output signal from the DUT and to measure the magnitude and the phase of the first fundamental signal; and a first reference receiver configured to measure the first magnitude and the first phase of the first cancellation signal, wherein the first signal source is adjustable based on the measured first magnitude and the measured first phase to provide the first cancellation signal having the first magnitude substantially equal to the measured magnitude of the first fundamental signal and the first phase approximately 180 degrees out of phase with the measured phase of the first fundamental signal.