Power measurement using network Analyser - RF Cafe Forums

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bansals_in

Post subject: Power measurement using network Analyser

Posted: Fri Jul 21, 2006 3:52 am

Lieutenant

Joined: Fri Jul 21, 2006 3:11 am
Posts: 2

Hi,
I am new to Network Analyser and I have to measure the output power of a device( HDSL Modem) which is in between 13 to 14 dbm, I would like to know whether it is possible to measure the output power with the help of network analyser and if yes.. pls let me know how..

Thanks..
Ashish

RFTEJerry

Post subject:

Posted: Fri Jul 21, 2006 8:12 am

Captain

Joined: Thu Apr 13, 2006 9:53 am
Posts: 17
Location: Florida

Hello Ashish and Welcome to RF Cafe,

A Network Analyzer (NA) can measure the output power in the range you have - 13-14 dBm. It would not be my first choice. More information is needed. Are you trying to measure CW, pulsed or other modulated power? Is the power peak or average? What accuracy do you need and is it absolute or relative power?

If simple CW I would use a power meter. It has high accuracy, easy setup and cost less than a NA. My next choice would be a spectrum analyzer for CW and especially or pulsed/modulated power. My last choice would be a NA due to cost, additional equipment and setup time. However, if all you have available is a NA then some of these issues are moot.

The method for measuring RF power using a NA is to perform an S21 (gain measurement). Some modern VNA have built in routines to do power measurements and the method should be explained in the users manual. The procedure is to involved to explain in this format. I would go to Agilent or Anritsu and download their application notes on network analyzers that detail how to do an S21 measurement. In addition Agilent has several excellent application notes on RF power measurement (AN-64, AN-64-1 and AN-1449-1, -2, -3).

Good luck,
RFTEJerry

bansals_in

Post subject: Power measurement using network Analyser

Posted: Sat Jul 22, 2006 1:40 am

Lieutenant

Joined: Fri Jul 21, 2006 3:11 am
Posts: 2

Hi..
Thanks for reply.
I am going for NA because it is only instrument available with me.
I have to measure output power of HDSL Modem for some testing.
It is 2B1Q modulated power as per ITU-T Rec. G.991.1

I have to measure peak power which is being transmitted on DLL lines by modem.
Presently I have Agilent E5100A NA with me and I have to measure with it.
So is it possible.

Pl. reply..

Posted 11/12/2012

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