A couple of questions about LTE:
1) I place the VSG200 output directly to the SA and I get a 5% EVM. Shouldn’t it be below 1%? There is not DUT involved.

2) Is there a way to get ACPR whil running LTE?

3) I went into the Spectral Mask mode and it seemed to fit rather well with the LTE I was using (20 MHz). Are there other “build in” SEMs? Or you do you have to build them yourself…just curious.

Thanks

jom

It might work for us. LTE might be better though…not sure yet. I’ll have to get this Matlab runtime thing going though….

As to your statement about the VSG60 I assume you meant VSG200 which is what we have.

jom

Hello

Another question on Dig Demod. I was using the OFDM modulation from the VSG200 but Spike didn’t seem to have a reciprocal Dig Demod choice from the pull down menu (such as the one for QPSK). Is this a licensing issue because it doesn’t warn you on that?

I was just doing a simple out from the VSG to the input of our SM200. We’ll be measuring an amplifier soon for EVM soon….

Thanks

jom

Is there a way to measure EVM (Error Vector Magnitude) directly?

jom

Info sent.

Thanks

jom

Right now the immediate need is to test an HPA. It has an SMA input port. I believe the system will have some version of QAM but I’m not entirely sure.

So if I read your response correctly the spectrum analyzer has an output that drives an input to a DUT (in our case an HPA) and take the DUT output and find EVM etc. So the spectrum has the ability to be an input device along with it’s normal function of being an output measuring device. Very interesting…I didn’t know that.

BTW, I assume the SP145 has a similar function…???

Thanks

jom

Thanks for the reply.

As to other capabilities: Does the BB60D handle EVM tests? If so, how would my DUT get an input signal for the spectrum analyzer to measure the DUT’s output? I’ve actually never run one of these before so I’m curious.

jom

Thanks Andrew.

Bottom line: which do you feel is best? My guess it’s the Lenovo. I’ve never been a fan of HP PCs (and the amount of garbage software they put on them) and I don’t know much about Dell. What do Signal Hound guys use?

jom

I’m glad someone brought this up. I’m curious as to whether the laptop (or even your desktop) needs to be super fast ALL of the time. Meaning are there different modes while running the SA where it doesn’t necessarily need a full speed processor?

I can see if you were doing some fast real-time spur search or whatever but what if you were just doing more “normal” measurements would it then be necessary to have a super fast PC?

Just curious.

Thanks

jom

Thanks Justin

OK, admittedly I kind of knew that already. I was hoping that there might be a setting in the SA that might get it above 6 GHz such as running at slower sweep speeds or some such.

Also, I was curious about the idea of moving down to 1-2 GHz in your suggestion. Is there a particular reason for that? Is converting down to, say, 5 GHz still OK? Just curious…

Frankly, I’m trying to talk myself into the BB60C but the SA124B might be a better deal. Is there something I might be overlooking here if I go with the lower cost model?

Thanks again!

jom

[Author]

Posts