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A simple question about PNA-L calibration using 85056D

Question asked by liuzhizhi00 on Jun 15, 2009
Latest reply on Jun 16, 2009 by liuzhizhi00

I am a rookie in this area and I really hope somebody can help me with my weird question. Thank you guys in advance.

I have a two-port PNA-L N5230A, and test cables (85133) are applied to each test ports. One of cable ends with a male 2.4mm connector and the other one female.

I started with one-port calibration on both of them. After the calibration, I found that the port which ends with female (so it's calibrated with male standards) seems fine, since the S11 with and without a standards open/short are around zero ( 0.1~0.2dB). However, the port which ends with male (so female standards are used for cal) looks not good. If I put short/open standards on, the S11 is still around 0.2dB, but if I just leave it open without any load, S11 changes dramatically, reaching to -15dB at some frequency points.

Then I used adapters on these two cables to change their sex, and did the 1-port calibration again on both cables. So at this time the sex of standards I used on each cable were different with standards used before. I find that the port which is now calibrated using male standards looks good, while it was weird if calibrated with female standards. On the other had, the port which in now calibrated using female standards looks unacceptable, while it was good if calibrated with male standards.

I am really confusing about this phenomenon. Can anybody give me some hints or suggestion? Your help will be appreciated.

Thank you.