Thread: E4405b power level trigger


Permlink Replies: 7 - Pages: 1 - Last Post: Jun 4, 2012 4:25 PM Last Post By: nexy_sm Threads: [ Previous | Next ]
nexy_sm

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Registered: 05/13/12
E4405b power level trigger
Posted: May 13, 2012 6:15 AM
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Hi all guys,

I am dealing with E4405b Spectrum Analyzer (SA), here at faculty lab. Unfortunately there is a lack of help here so I have to ask you a few things.
I want to set my SA to trigger at certain power level, for example, I am monitoring spectrum that is 1MHZ arround 868.65MHz center frequency, and I am expecting my transmitter to send some signal at some point in time. The SA should trigger as soon as it detects given power level in that spectrum, and to freeze picture (something like single sequence with oscilloscopes). I was working once with 50kg high end spectrum analyzer and those kind of measurements were set-up in a 10 seconds, but here se kind of complicated or it is even not posible.

Thank yo and hope somebody is able to help me.
xmo

Posts: 49
Registered: 03/05/07
Re: E4405b power level trigger
Posted: May 23, 2012 9:25 PM   in response to: nexy_sm in response to: nexy_sm
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Hi,

Have you developed a solution to this problem yet?
nexy_sm

Posts: 4
Registered: 05/13/12
Re: E4405b power level trigger
Posted: May 24, 2012 12:39 AM   in response to: xmo in response to: xmo
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Unfortunately not yet.
xmo

Posts: 49
Registered: 03/05/07
Re: E4405b power level trigger
Posted: May 24, 2012 7:35 AM   in response to: nexy_sm in response to: nexy_sm
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If you are connecting directly to the device that generates the signal you are trying to observe, one possible solution could be the 85902A carrier burst trigger unit:

http://cp.literature.agilent.com/litweb/pdf/5091-7292E.pdf

Agilent has discontinued this item but you might find one at a reasonable price on the secondary market.
nexy_sm

Posts: 4
Registered: 05/13/12
Re: E4405b power level trigger
Posted: May 29, 2012 5:44 PM   in response to: xmo in response to: xmo
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Thank you, something like this could help, but I still cannot believe that this spectrum analyzer doesn't have this feature already integrateed. It is completely useless in todays applications when you want to catch some burst in undetermined moment in time. Does anybody have any experience with this machine?
xmo

Posts: 49
Registered: 03/05/07
Re: E4405b power level trigger
Posted: May 29, 2012 7:51 PM   in response to: nexy_sm in response to: nexy_sm
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I believe that the ESA-E can have that feature "already integrated"

In the "Trigger Concepts" section in manual E4401-90482:

"Measurement Guide and Programming Examples - PSA and ESA Series Spectrum Analyzers"

It says:

"...If you have firmware A.08.xx or later and Option B7E with board part number E4401-60224 or higher, RF burst triggering is also available ..."

If your instrument does not have that option installed, an Agilent support person should be able to advise you if it can still be ordered as an upgrade.
tabbott


Posts: 1,483
Registered: 07/24/09
Re: E4405b power level trigger
Posted: Jun 4, 2012 4:08 PM   in response to: xmo in response to: xmo
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Hi -

The Digital demodulation board set of option B7D and B7E will provide an internal burst trigger. In fact, it provides a key under the Trig menu that lists RF Burst. This trigger option allows the analyzer to be triggered by an RF burst envelope signal. The trigger level can be set to either a level relative to the peak of the burst or to an absolute value. This board set (B7D/B7E) can be retrofitted into an ESA, but there may be other options to consider.

Options to consider:

• B7D, DSP board
• B7E, RF Downconverter
• 1D5, Precision frequency reference
• B72, Expanded Memory
• 1D6, Time Gating (for analyzing time varying signals)

Regards -
nexy_sm

Posts: 4
Registered: 05/13/12
Re: E4405b power level trigger
Posted: Jun 4, 2012 4:25 PM   in response to: tabbott in response to: tabbott
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HI all,

our spectrum analyzer has B7E option and appropriate firmware version (I am not able to recall precise version now). But I still don't understand what really means B7E and simmilar modules.

Under trigger menu, there is an option RF burst, but obviousely, I wasn't able to set up scope correctly in order to have adequate measurements.

I set center frequency to 2.4GHz because we have wireless router near the spectrum analyzer, and in the free run I was able to se wifi signal in the display, and to figure order of absolute power. In the next step, I set RF burst as trigger, and put appropriate power level as a trigger treshold, but SA (spectrum analyzer) wasn't triggerred at all. Then I lowered trigger level, ant SA started to trigger when that level was at the same level as noise. I don't know why it happened in this way, and thus there is a question, whether I should use normal input for those kind of measurements, or some of the inputs from mentioned modules at the back of SA.

Many thanks

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