The RF SFDR (Spurious Free Dynamic Range) of NI-USRP is not calculated in USRP's latest datasheet or user guide. For some NI-USRPs, the DAC and ADC sFDR are available in the datasheet, however, the USRP daughterboard components will degrade the sFDR. With NI-VST, it is not difficult to measure the transmitter sFDR, however, it is not easy to measure the receiver sFDR. This article will take X410 as an example and show how to calculate the receiver sFDR from IP3 which is available in the datasheet. The intended audience is PXI USRP users who have basic knowledge of RF device's performance and interference. 

1. Refer to wikipedia Spurious-free_dynamic_range the sFDR is calculated below             

2. Refer to SFDR-calculator for an online tool based on the above formula.
3. Refer to attached X410 specifications, IP3 = 12dBm, the noise figure NF = 9dB for the worst case

4. Consider the received signal Bandwidth 50kHz and a SNR (signal to noise ratio) of 2.5dB, the thermal noise floor is -174dBm, the MDSL (Minimum Detectable Signal Level) equals: -174dBm+9dB+10log(50000)+2.5=-115.5dBm

5. The SFDR is 85dB calculated from the tool of step 2