Why are spectrum analysers with BW over 2.5GHz in one go US ITAR controlled?

[peter-h]

This is probably why so many are 2.4GHz...

Is it to make it harder to pick up spread spectrum covert comms signals?

[Bicurico]

Are you sure about that?
Plenty of SEA in eBay with huge BE.
Never heard of an IT AT issue...

Regards,
Vitor

[rs20]

The BB60C has no special export restrictions, and goes to 6 GHz.However, they did have to pull a trick seemingly unrelated to BW to achieve this: see link here.

Maybe there's a popular cheap chipset that maxes out at 2.4GHz, hence the frequent appearance of this max?

[coppice]

I don't think they are ITAR controlled. China is not an ITAR permitted country, and Keysight China sells up to 110GHz SAs.
I think cheap up to 2.4GHz SAs are popular because they use consumer grade SDR chips and these chips are in ISM band.

Huge amounts of ITAR controlled stuff is sold in China. Being ITAR controlled doesn't stop things being sold in most countries (there is just a short list of countries, that includes North Korea, Sudan and a few others, that are totally excluded). ITAR control means a licence is required for each sale. Getting a licence requires verifying the end user, and their purpose in purchasing the equipment. There is no guarantee of getting a licence, but its not hard to get them to sell a wide range of controlled technology to non-defence businesses in China. Only really advanced technology is hard to sell into most commercial applications.

[ebclr]

Who cares about ITAR

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[ChuckDarwin]

No idea on the BW issue.
If the majority use of the system is related to national security, defense or space, then the export is classified under ITAR rules.   If it has both a  common commercial and defense use, then it is managed under the Commerce Dept "Dual-Use" system, where you (and the gvt) make a case as to the intended use, originator and end-user and the item is either classified as munition related or as commercial use and you apply the appropriate export controls.   Then the layers of tariffs, trade sanctions, limits, agents, etc. 
Commercial use has always had some diversion into defense and like areas.  The classification becomes more complicated in the software defined era when feature sets are already baked waiting to be unlocked or easily soft loadable.   Consider software unlockable analyzers, precision machining equipment, processor features. 

A problem, in particular,  with TE and machine tools, is that almost everything can be dual-use. 
If you look at the Wassenaar Arrangement you will be surprised at the range of categories that are listed as dual-use.
Read About, then List of Goods if interested: http://www.wassenaar.org/about-us/

Over time, use classifications evolve with technologies and markets.  Satellite technology was once classed as a munition, now it is dual use.  Processors were classified by capabilities, as exportable or not.  Been a long time, they may still be.  You would also run into the occasional comedy of not being able to export a item back to the country of origin. 

[peter-h]

OK; it looks like the restrictions have moved to the FMT feature, which is obviously great for detecting covert spread-spectrum comms

[GlowingGhoul]

Who cares about ITAR

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Chinese military hardware, particularly that based on stolen technology they have no fundamental understanding of, is known to be the lowest quality equipment on the planet.

[rfbroadband]

I forgot the exact details, but ITAR specifies one case that describes the ability to do very fast broadband frequency hops/step (let's say 100MHz to 2.x GHz in less than x ms) -> read he ITAR definitions for the correct exact numbers.

I was once involved in the design of broadband synthesizer chip that could hop extremely fast between (any 2 freq.) between 50MHz and 7GHz and the specs. we achieved triggered ITAR restrictions. I think the concern here was such a device could be used by 'anyone' to implement very fast frequency scanning receivers...