SFDR

[Tejeswar]

I have a requirement where my customer is asking to prove the SFDR specification of my AWG 5451, VSG 5672, VSA 5661 and HSD 5622. I have to programmatically prove this specification for the above hardware. I don't know the procedure to test this specification for the above hardware

[Hardik.Asawa]

Hi Tejeswar,

For doing any measurement for vsg/awg, you need to have a analyzer/scope with better specifications. For exmaple, if we want to measure SFDR, generate a sine tone for given frequency using awg. In terms of instrumentation that can be used to perform these measurements on a generator, you need a device with better specifications than the device under test (DUT). This will make sure that the we don't have measurement error. A great deal of information on SFDR can be found on the web, including the National Instruments website. A good article related to SFDR and how to measure it is 

KnowledgeBase 2N8D0BN5: What is Spurious-Free Dynamic Range?.

Similarly, to validate specifications of analyzer/scope you would need to provide it a pure tone. For example, for calculating SFDR for analyzers, you can apply a pure tone into the board. Calculate the difference between the peak corresponding to the tone, and any spurs in the noise floor. This value should be as large as the spurious free dynamic range in the specifications for the board. Note, it is important to use a pure tone so that if you do see distortion, you can determine that is coming from the board and not the signal.

Hope this helps.

Regards,

Hardik Asawa