Abstract: A multimode network analyzer (VNA) and the method of using the same are disclosed. The VNA includes a signal input port that receives a test signal, an LO signal generator, a mixer, an IF filter and a processor. The LO signal generator generates a mixer LO signal from a mixer input test signal, the LO signal generator having first and second modes. The mixer LO signal is substantially a first periodic signal in the first mode and a second periodic signal having a plurality of harmonically related tones in the second mode. The mode that is currently operative is determined by a mixer control signal. The mixer is driven by the LO signal and has an output that is filtered by the IF filter to generate an IF signal. The processor analyzes the IF signal to determine a parameter characterizing the test signal and outputs that parameter.

Abstract: A filter that includes an analyzer, thresholding circuit, and synthesizer. The analyzer generates a low-frequency component signal and a high-frequency component signal from an input signal. The thresholding circuit generates a processed high-frequency signal from the high-frequency component signal, the processed high-frequency signal having an amplitude of zero in those regions in which the high-frequency component signal has an amplitude that is less than a threshold value. The synthesizer generates a filtered signal from input signals that include the low-frequency component signal and the processed high-frequency signal. The filtered signal is identical to the input signal if the threshold value is zero. The analyzer is preferably constructed from a plurality of finite impulse response filters that operate on a small fraction of the input signal at a time.

Abstract: A distortion measurement method uses alternative measurements to determine the distortion of a DUT, depending on the ratio of the distortion at an output of the DUT to distortion of a source stimulating the DUT. The method includes calibrating the VNA at a distortion frequency, measuring a first gain of the DUT with the source and the receivers of the VNA set to the distortion frequency, and measuring a second gain of the DUT with the source of the VNA set to a fundamental frequency and the receivers of the VNA set to the distortion frequency. When the second gain is less than a predesignated threshold, a match-corrected source signal is acquired and used with the first gain and the second gain to determine the distortion of the DUT. When the second gain is not less than the predesignated threshold, a match-corrected DUT output signal is measured and used with the first gain and the second gain to determine the distortion of the DUT.

Abstract: A distortion measurement method uses alternative measurements to determine the distortion of a DUT, depending on the ratio of the distortion at an output of the DUT to distortion of a source stimulating the DUT. The method includes calibrating the VNA at a distortion frequency, measuring a first gain of the DUT with the source and the receivers of the VNA set to the distortion frequency, and measuring a second gain of the DUT with the source of the VNA set to a fundamental frequency and the receivers of the VNA set to the distortion frequency. When the second gain is less than a predesignated threshold, a match-corrected source signal is acquired and used with the first gain and the second gain to determine the distortion of the DUT. When the second gain is not less than the predesignated threshold, a match-corrected DUT output signal is measured and used with the first gain and the second gain to determine the distortion of the DUT.

Abstract: A filter that includes an analyzer, thresholding circuit, and synthesizer. The analyzer generates a low-frequency component signal and a high-frequency component signal from an input signal. The thresholding circuit generates a processed high-frequency signal from the high-frequency component signal, the processed high-frequency signal having an amplitude of zero in those regions in which the high-frequency component signal has an amplitude that is less than a threshold value. The synthesizer generates a filtered signal from input signals that include the low-frequency component signal and the processed high-frequency signal. The filtered signal is identical to the input signal if the threshold value is zero. The analyzer is preferably constructed from a plurality of finite impulse response filters that operate on a small fraction of the input signal at a time.