That appears to be an "RP SSMA" or "Reverse Polarity SSMA" connector
IF you find an SSMA (or other connector of the same size but it is not an RP version as your is, you could make an adequately workable one off by machining down a plug (whose centre will fit your plug) and then ensuring that adequate outer contact is made. Even if this involved bonding (eg soldering) your unit to a cut down plug it would work if done well.
SSMA is a (even more) miniature version of SMA.
RP or reverse polarity is when the plug centre is a male pin rather than a socket and the outer is a male thread, as shown in your picture.
This image from Wikipedia - SMA Connector shows an RP connector (as yours is) but this is an SMA.
Amphenol SSMA with catalog - may not have RP
Southwest Microwave - have SSMA PLUS smaller, still smaller and still still smaller versions.
One MAY match yours. May not have RP.
2.92 mm, 2.40 mm, 1.85 mm versions !!!
1.85mm - 67 GHz !!! - not RP as shown here
Dimension chart below from here
Notionally reverse SSMA images - MAY be of some use - note that many are not RP SSMA.
Future RP SMA - MAY know of SSMA
Aliexpress and similar can be a source of specialist parts - these are not exactly what you want but show that small volume sellers of semi-specialist parts can be found.
RF Globalnet SSMA
Microwave 101 connector page
Amphenol may save you - or not
Southwest microwave catalog pages
... beyond the catalog.