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Features of the Agilent PNA Frequency Offset:
Option 080 frequency offset capability enables the network analyzers to set the source frequency independently from where the receivers are tuned. This ability is important for two general classes of devices: mixers (and converters) and amplifiers.
For frequency-translating devices like mixers or converters, frequency-offset capability is necessary for conversion loss/gain measurements (both amplitude and phase), since, by definition, the input and output frequency of the DUT are different.
For amplifier measurements, frequency offset capability is required to measure amplifier harmonics or when using the internal source as one of the stimuli of a third-order intercept (TOI) or IP3 measurement.
For analyzers with the built-in second source, Option 080 is required to control the frequency of the independently tuned second source.