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Test setup with Agilent 8753ES Network Analyzer

Question asked by KenLi on Oct 11, 2010
Latest reply on Oct 15, 2010 by Dr_joel
Hi all,

Good day.
I am trying to measure the S21 parameter (to get the bandwidth) on a switch IC, however the -3dB BW value on the S-parameter is way too low that the expected BW value.
Need some advice.

Equipments used:
1) Agilent 8753ES Option 006 Network Analyzer (50 Ohm Network Analyzer)
2) 8120-4948 Agilent Cable Assembly 36" -3.5mm
3) 2x PCB boards (one for calibration and another for test so the trace length use for calibration is exactly similar to the test trace lenght)

My test board will have 75 Ohm on the switch input and 75 Ohm on the switch output.
Basically i am measuring the switch at 75 Ohm environment with 50 Ohm network analyzer.
I am using Full-2-Port SOLT calibration with 75 Ohm as the load.

I do not have any 50 Ohm to 75 Ohm adapter connected as i was thinking that the calibration should have taken care on the 50 Ohm and 75 Ohm mismatch.
Do let me know is that the reason why i am getting a lower -3dB reads.

By the way, which cal kit that i should select if i am using my own PCB board for calibration.