Option 028 adds firmware for high-accuracy noise figure measurements of amplifiers, frequency converters, and mixers using a PNA or PNA-Xs standard S-parameter receivers, and utilizing Agilents unique source-correction technique. Using a PNA or PNA-X and an Agilent ECal module configured as an impedance tuner, the effects of imperfect system-source match and receiver noise figure are fully removed, greatly improving the accuracy of the cold-source technique. This approach surpasses the accuracy provided by the Y-factor method and other cold-source implementations.
Fully corrected noise figure measurements require an ECal module (m-f recommended) and a power meter (both must be ordered or supplied separately). A scalar calibration choice is also available that offers less accuracy, but is faster and does not require the ECal module used as an impedance tuner. During calibration of the analyzer, an additional ECal or mechanical calibration kit is required. The power meter is only used during calibration of the analyzer.
Using the standard receivers instead of Option 029s dedicated low-noise receivers places some restrictions on the measurement setup, based on the device-under-test (DUT):
- The DUT (or DUT plus system preamp) must have enough excess noise (gain + noise figure in dB) to overcome the inherent noise of the standard receivers. An external preamplifier is required if the DUTs excess noise is < 30 dB up to 20 GHz, < 40 dB up to 50 GHz, or < 45 dB up to 67 GHz.
- When using an external preamplifier or when measuring unfiltered DUTs like broadband amplifiers, external filters are needed to eliminate harmonic noise conversion that would otherwise cause an increase in measured noise figure. High-gain DUTs with built-in filtering, like typical up or down converters, don't require external filters.