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PNA-X configuration for power FETs model validation

Question asked by reseng on Mar 1, 2012
Latest reply on Aug 22, 2012 by reseng
Hello,
We would like to order a N5242 for the purpose of FET (GaAs,GaN) models characterization (non X params). We also selected noise measurements option 029 which demands to order 219 or 285 power configuration. Option 219 provides build-in attenuators and a bias tees and 30 dBm limit on receiver port. Build-in bias tees has limitation 40V and 200 mA which is not enough for us so we choose to order external ones. If I understand right, typical procedure will be to measure S parameters at different biases at source power settings about -20 dBm -l -10 dBm. Expecting 15 dB gain we don't need external attenuators during parameters extraction measurements. To validate our extracted FET model we need to use a higher power signal. If we set 10 dBm source power at perfect match one can expect 25 dBm at receiver which is still below 30 dBm power limit.
1) Is it right setup for model validation measurements or we need some how to reduce amplitude using external attenuator somehow plugged in PNA-X receiver test set? Do we need external low loss directional couplers, signal generator and amplifier in the test set? Is N5242-285 option (20 W, no internal bias tees) will be a better solution then 219? Would you be so kind to clarify this question so we can order a right configuration of our measurements setup.
I saw pulsed solutions from Auriga and Amcad but for a moment they are not available for us.
2) Second question concerning noise figure measurements of a FETs using the wafer probe. ECal module is intended to find 50 Ohm input impedance NF, but to find minimum NF point at input impedance map most probable we need to use a tuner to get a lager map. The Maury noise characterization solution again is not for now. How we can use a manual tuner to obtain a noise figure of a FET? Do we need an ECal module for calibration in this setup?
3) Load pull measurements using manual tuners on wafer probe. If I understand right we need a microwave source, power amplifier, input tuner, probe station, output tuner, power meter. Should we use somehow a PNA-X and ECal in this setup for calibration or power measurements? Do we need couplers?
4) Is it possible to use Agilent B2902A source/measure unit connected to PNA-X through external bias-tees to measure DUT(FET) IV characteristics? DUT will be connected through RF probe. B2902 is intended to be used as a bias source during S parameters measurements, but if we can use it to measure IV at the same connection it will be good.

Thank you in advance,
Oleg Tokmakov  

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