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Thread: E5071C default (preset) calibration


Permlink Replies: 2 - Pages: 1 - Last Post: Jun 21, 2012 4:15 AM Last Post By: beaRTS Threads: [ Previous | Next ]
Jeff Goos

Posts: 1
Registered: 04/26/12
E5071C default (preset) calibration
Posted: Apr 26, 2012 4:54 PM
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Easy question...

I have a E5071C 2 port 8.5GHz network analyzer. My question is regarding what calibration exists (if any) when the preset button is pressed. Is there a full range 2-port factory calibration to the front panel N connectors? Or is there no factory calibration?

In this application I have an N connector cable (12 feet of LMR400) that I want to make accurate loss measurements with from 1GHz to 8.5GHz. I see two ways to do this:
1) I have an ECAL module with SMA connectors. I can cal the machine over the 1-8.5GHz range with the ECAL, but must include 2 semi-rigid cables and 6 adapters. To de-embed back to the front panel N connectors I can use port extensions with loss compensation using the OC auto port extension (with adapters and semi-rigid removed). This works, but I'm questioning the accuracy. I can see on the smith chart this broad band port extension is not compensating for loss accurately across the band.
2) If the machine has a factory calibration the easiest thing to do is connect my N connectored cable to the N connectors on the network analyzer. No adapters, user calibration, or port extensions necessary.

I tried it both ways to see if they would match, they do not. Using the ECAL procedure stated above I see about 1dB more cable loss in the mid band.

I'm looking for accuracy that is a+/- about 0.1dB.

Thanks.
Dr_joel


Posts: 2,741
Registered: 12/01/05
Re: E5071C default (preset) calibration
Posted: Apr 30, 2012 7:34 AM   in response to: Jeff Goos in response to: Jeff Goos
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An inserstion loss error of less than 0.1 dB requires high quality calibrations at the test ports on the order of about 30 dB residual source and load match. Typical connectors at these frequencies are on the order of 20 dB. Thus, to acheive the desired level of 0.1 dB insersion loss error, you must use a moderate-to-high quality type-N calibration kit at the reference for the DUT. There is really no other choice for the level of quality that you specify. For your setup, you can expect abuot 0.68 dB p-p ripple.
beaRTS

Posts: 1
Registered: 06/18/12
Re: E5071C default (preset) calibration
Posted: Jun 18, 2012 10:03 PM   in response to: Dr_joel in response to: Dr_joel
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You can watch the calibration steps here http://www.youtube.com/watch?v=CRDhzMqhayU&feature=plcp

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