In a two-tone intermodulation test, which metrics are typically reported?

In a two-tone intermodulation test, which metrics are typically reported?

• A. IMD3 and IMD5
• B. SNR and BER
• C. Carrier leakage
• D. VSWR

Answer: (A)

Two-tone intermodulation testing looks at how a nonlinear device creates distortion when driven by two signals. A linear device would pass only those two tones, but real hardware generates intermodulation products at sums and differences of the tones. The most important of these are the third- and fifth-order products, which show up as new frequencies such as 2f1 − f2 and 2f2 − f1 for the third order, and related components for the fifth order. Because these distortion products are the clearest indicators of nonlinear behavior in the region near the originals, the metrics typically reported are IMD3 and IMD5. They are usually expressed in dBc (decibels relative to the carrier) at specified output levels, giving a direct measure of how much those unwanted tones are present compared to the desired carriers. Other metrics like SNR and BER pertain to digital system performance, carrier leakage describes how much of the input leaks into the output without generating new tones, and VSWR concerns reflections due to impedance mismatches. So IMD3 and IMD5 are the standard way to quantify two-tone intermodulation behavior.

Two-tone intermodulation testing looks at how a nonlinear device creates distortion when driven by two signals. A linear device would pass only those two tones, but real hardware generates intermodulation products at sums and differences of the tones. The most important of these are the third- and fifth-order products, which show up as new frequencies such as 2f1 − f2 and 2f2 − f1 for the third order, and related components for the fifth order. Because these distortion products are the clearest indicators of nonlinear behavior in the region near the originals, the metrics typically reported are IMD3 and IMD5. They are usually expressed in dBc (decibels relative to the carrier) at specified output levels, giving a direct measure of how much those unwanted tones are present compared to the desired carriers. Other metrics like SNR and BER pertain to digital system performance, carrier leakage describes how much of the input leaks into the output without generating new tones, and VSWR concerns reflections due to impedance mismatches. So IMD3 and IMD5 are the standard way to quantify two-tone intermodulation behavior.