Anritsu MG369nB signal generators have 2.92 mm connectors for 10/20/30/40 GHz models and 1.85 mm for the 50/67 GHz models.
We use a 1.85 mm to 2.92 mm adaptor on a 50 GHz Anritsu generator where it is used < 40 GHz most of the time. This also serves as a port protector.