Identification of RF power transistor


Joined Feb 24, 2006
I have acquired a couple of these but can't find a data sheet. Any ideas?

Markings: 'ST' logo; 1222-13 56A

Best guess is a custom design for a customer. The markings would be intelligible to the company and the customer, but nobody else. The datasheet is probably buried in deep underground vaults. There is hope if you have half a million dollars to invest in a network analyzer and an s-parameter test set, you can characterize them yourself