winglj
Joined: 21 Feb 2005
Posts: 191
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 06 Jan 2006 5:50 Antenna Measurement Problem |
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Hi, everyone.
I am now doing some antenna measurement with HP 8510 network analyzer. I also connect the RF signal generator to a extender to do the anechonic chamber measurement.
Every thing is OK while doing bench test for S parameter, but for chamber measurement, the network analyzer always shows that the IF signal overload, even I try to reduce the signal generator output to its minimum (-20dBm).
By observing the receving signal, it seems at lower frequency which the receving signal over -10dBm (I am not sure, but the network analyzer shows channel 'a' is -10dB), the IF will overload.
My question is whether I need to add a 10dB attenuator to the extender to overcome this problem?
Thanks in advance.
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sergio mariotti
Joined: 22 Dec 2003
Posts: 467
Helped: 42
Location: Italy
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06 Jan 2006 10:05 Re: Antenna Measurement Problem |
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I'm not sure... but i think that for antenna measurement, a special set of instruments are needed. I don't rem. the name but it's basically an 8510 but taylored for antenna measurement.
To answer more specifically to your question.... Have you applied the rough law " longer the cables, slower the measurement" ? This topic is well described on Agilent AN1291-1B. Without ad hoc delay lines (that are placed on the rear of the 8510 rack), you only perform very slow measurement ( i.e. 20 sec for 20 meter log cables)
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