Nice intro and overview as always.... however the doubler test setup for the phase noise test was a bit bizarre.
It looked to me like the amplifier after the doubler has a lot of gain (45dB?) and the doubler was being under driven to compensate for this. All very strange.
The amplifier has about ~25dB of gain at 8GHz. The doubler would have been sufficient without the amplifier.
Would it not have been better to drive the doubler properly and dispense with the Avantek amplifier? The phase noise test would have had a bit more credibility. Also I suspect that the phase noise of the analyser itself would be playing a part in your tests. Especially at offsets very close to carrier.
The purpose of the amplifier was to show the rise of the noise floor and its impact on the phase noise measurement. The whole point was to show how three regions of the phase noise measurements are impacted by various effects:
1) Close in phase-noise is dominated by the instrument's own internal phase noise and thus the two measured curves line up. I offered this as a puzzle to the viewers.
2) Mid-range phase noise is scaled mathematically based on the consequence of the doubler.
3) Far out phase noise is increased beyond the expected 6dB due to the excessive noise from the amplifier.
This is a valuable test to teach people what to watch out for. Other than that I know how to optimize phase noise if it was the only goal.
Finally, I can't understand why you think your backscatter test was 'really testing' the dynamic range of this analyser. It didn't look to be a tough test at all. There are various ways to really test the dynamic range of this analyser but I don't think that was one of them.
The backscatter experiment does not really test the dynamic range of the instrument during regular measurement but it shows the limit during real-time measurement and that was the point. I chose the TX/RX power to be close to the limit of the real-time digitization dynamic range. Also, I need to make a fun experiment not just "verify" the spec, anyone can just look that up from the datasheet.