Quick Spec Questions on the 5665 and 5668R

[GSmithRADX]

Hi - I am wondering if someone who knows the PXIe-5665 and PXIe-5668R can help me figure out if either can meet several specs we were given as customer requirements.

Upper frequency range for the input is 7 GHz, and analysis bandwidth of 40 MHz. 5665 supports 14 GHz, and 50 MHz; 5668R supports 26 GHz, and 80 MHz for about the same price.

What I am not sure of are the following requirements:

1) Requirement for Attenuator Range 60 dB

2) Requirement for Attenuator Step 10 dB
* I believe the 5668R step attenuator step size is 5 dB
* Not sure what the step attenuator step size is for the 5665

3) Requirement for 110 dB Dynamic Range 3rd Order at 1 GHz

Customers sometimes tend to give us box instrument specs, and at times those don't seem to easily map to PXIe instruments specs. Anything anyone can do to help educate me on the above would be great - thanks!

[Ben_Co]

Hey GSmithRADX,

Looking at the 5668R and 5665 specification sheets (found here respectively: http://www.ni.com/pdf/manuals/376232c.pdf page 11, http://www.ni.com/pdf/manuals/375605e.pdf page 10/11) it looks like the VSA's have the following attenutation ranges:

5665 3.6 GHz: 0-30dB in 10 dB steps

5665 14 GHz: 0-75 dB in 5 dB steps

5668R: 0-75 dB in 5 dB steps. 

That should answer questions 1 & 2. As per question 3, it looks like the 5668R has somewhere around -32dBm of Third Order Distortion at 1GHz, (page 30 in the spec) and the 5665 has roughly 31 dBm (page 30 in the spec as well). 

Let us know if that's what you were looking for. 

Thanks,

Ben

Applications Engineer 

National Instruments

[KittF]

Clarifiction perhaps:

Table for 5668 dynamic range (DR) at 1GHz (fig 4, p.30) shows nominal 3rd order DR of about -117 dBc. This max DR is found when the power at the mixer is about -36 dBm (you can adjust VSA settings to vary the power at the mixer). The 5665 results are very similar (fig 5, p.30).

Kitt

[GSmithRADX]

Yes - that helps a lot, guys.  Thanks!