Is the YIG tuned oscillator still used in modern microwave signal sources?

[alan.bain]

This question should I thought be easy to answer by looking at some keysight service manuals, but they don't seem to be like the HP manuals of days gone by.... in fact they seem to say almost nothing about how the test gear works. Hopefully some engineers are curious enough to remove the covers?

Is the principal voltage controlled oscillator in microwave generators still the YIG tuned oscillator or has that gone the way of the BWO? In which case what has replaced it?  Appreciate that the band which was easily attained directly has increased, but even the multiplier type generator tended to use a YIG tuned filter to pick the right harmonic.

Alan

[pdenisowski]

We (R&S) use YIG oscillators in some of our generators:

" For applications requiring the lowest possible phase noise across the entire offset range, an option with a YIG oscillator is available that can be used to attain a value of –132 dBc/Hz
(typ.) for a 10 GHz output frequency at offsets from 10 kHz to 100 kHz."

More in the article about the YIG oscillators:

https://cdn.rohde-schwarz.com/magazine/pdfs_1/article/218/english_21/NEWS_218__09_SMA100B__english.pdf