Frequency Response

[Nick_Kimi]

Hi there,

I would like to measure the frequency response of a radio frequency current transformer (as attached) using DSA815 1.5 GHz Spectrum Analyzer. How can I do that? I try a few times, and this is what I got (as attached) and I don't think it represent the frequency response of the sensor.

Many apologies for any inconvenience caused.

[awallin]

Do you have a model number for the sensor and a datasheet?

Post a schematic of your measurement setup. What are you measuring and how?

[Nick_Kimi]

Hi Awallin,

Thanks for replying my post.

Yes, I do have the model number for the sensor and a datasheet, all the information of the sensor are there. However, the sensor's performance will decrease by time. That is why I want to measure the frequency response of the sensor again. I need to have it in order to validate my results.

I want to measure the frequency response of the sensor. I should have something as attached no.1. I followed one of the EEVblog video ( ) but I did not get it.

As attached no. 2 is my schematic of the measurement. And I'm not really sure the measurement setup is correct or not.

cheers.

[Alex Nikitin]

And I'm not really sure the measurement setup is correct or not.

It is not correct. To measure the response of a current sensor you need at the very least to make reasonably flat the source current frequency response. To do it you have to use a matched load and a coaxial feed. For starters you can use a 50 Ohm coaxial cable from the generator's output with a 50 (47 or 51) Ohm metal film resistor at the end of it, placed in the transformer opening. It would not be a very accurate method but miles better than what you've tried.

Cheers

Alex

[babysitter]

Mr. Smith describes a lot of suitable DIY probes and talks about ther characteristics, one of the simplest:

http://emcesd.com/tt080699.htm

babysitter

[Nick_Kimi]

Hi Alex,

Thanks for replying my post.

Oh yeah, it's make sense. As attached is the measurement schematic, is that what you mean right? And then I need to make sure that I use a correct value of resistor, right?

cheers.