Specifications in PXIe-5842

Answers can be based on spec mapping/interpreting and Radar application knowledge. 

1. Frequency Range(GHz): 30 MHz to 18 GHz

2. Input Impedance (Ohms) 50 Ω, nominal

3. RF Power Levels (dBm): RF Out & RF In

4. Recovery Time (µS): Not exactly sure what this spec is referring to... but maybe Frequency Settling or Amp Settling?

5. Bandwidth (MHz): Up to 2 GHz

6. Channel to Channel Isolation (dB) (for 4 channel option): Not Spec'd that I know of. In my own testing, RF Out to RF In has 120 dB of isolation or better (not comprehensive testing but sweeping CW across certain bands of a 26.5 GHz unit). Expect far better isolation than that across multiple 5842's. However, I would highly recommend testing if this will be a critical customer spec. Note: if the customer ever wants to move to the mmRH in the future, the RMM-558x products do not have good TX<>RX isolation and I would expect that the 5543 IF Switch also does not have as good isolation compared to just RF In and RF Out on the 5842 itself (But I haven't tested this).

7. Gain of receiver (dB): Table 16 But since we're a calibrated instrument the gain is handled by the driver and end users set an Absolute Reference Level (dBm). Customer is likely thinking in the context of Radar Link Budgets where they need to plug "Gain" into their equations. Using a VST to emulate a Radar and/or measure radar responses you'll set a Reference Level adequate to pick up the signals of interest (e.g. Ref Level to Displayed Average Noise Level (DANL) or Ref Level down to the Noise Floor of the instrument will dictate your ability to pick up Radar returns). So, they'll set RF In Ref Levels according to Table 15 and RF Out power levels according to Table 29 & 31 and not have to think about Gain.

8. Sample rate of ADC: Regardless of what the ADC is doing (up to 5 GSps) customer is going to be limited to the resolution of the model they purchase and the IQ Sample rate is always 1.25*BW. So, if they buy the 1GHz BW 18 GHz variant then they'll get 1.25 GSps. Table 54

9. Noise Figure (dB): RF In Noise Density & RF Out Noise Density. Compare those numbers to -174 dBm/Hz (using 293 Kelvin as ~room temp): https://www.everythingrf.com/rf-calculators/noise-power-calculator & https://www.nist.gov/pml/owm/si-units-temperature

10. Switching Time (nS): Switching Time of what? We don't have a bidirectional RF port on the base 5842 models so I'm guessing this refers to On/Off Switching time of the Pulse circuitry? If so, maybe table 48 applies. If referring to Frequency Switching then table 13 BUT there are efforts to get this more in the 10's of us range if not faster with roadmap HW (but export restricted for sure). If needing to freq switch faster then there are options to do it in the IQ data itself as long as the scenario is within the IBW of the instrument (1 GHz in this case but up to 4 GHz with the 5842). If in-band tuning within the IQ data you can hit ns numbers easily.

11. Radar signal types: See RFmx WC manual. However, the 5842's currency is IQ data - if the customer has their own unique radar waveforms we can play it out as long as the sample rates fit

12. Frequency resolution: ≤1 Hz

13. Radar Pulse Width: Can be IQ Data Driven based on Sample Rate and the associated time domain resolution (e.g. 1.25 GSps gives 800 ps of resolution per sample point vs 5 GSps 200 ps of resolution). Need to have enough samples to represent a decent pulse rising, on time, falling edges so rough guess in the 10 ns+ range. If using the Pulse circuitry on the 5842 itself then table 47 is a good starting point.

14. Pulse Width accuracy: Can be a combination of the IQ Data and the physical HW circuitry. Bit hard to answer as it'll be use case/context specific.

15. Pulse Width resolution: Same as width accuracy comments above but also can be a combination of IQ data sample rate resolution if doing pulsing digitally along with the HW circuitry. If operating in RFSG CW mode then only the Pulse Modulation specs will apply.

16. Through 18. PRI range/accuracy/resolution: Table 48 but again, depends on the application specific use case of IQ data along with the physical circuitry. Table 43 details jitter when using external Pulse Mod. Might need additional testing if driving from RFSG Scripts. Comment on Range - minimum to infinite PRI and Pulse Width depending on internal or external use cases (e.g. could pulse on and never pulse off when IQ data is CW). Also, if using the Pulse Mod 5842 circuitry then some of the accuracy/resolution numbers can be gleaned from the Latency, Jitter, and Resolution numbers in the Triggering section

    19. Pulse traffic: Not sure what this means? I'll make an assumption that this is referring to how many pulses across BW but that is really up to the customer to define in their IQ data. ADG BU is working on streaming multiple emitters out of a 5842 but you'd have to speak with your Business Manager on how to navigate export restrictions (if not AMER).

    20. Range of scan measurement: I'm not aware of us spec'ing scan rate of the HW but some assumptions can be made from the frequency settling and amplitude settling numbers. However, this will be application specific and whether they use default RFmx SpecAN frequency sweeps or write their own carrier frequency sweeps at full bandwidth of the instrument.