This part is a kind of semiconductor called AM1214-250.

Function of this product has RF POWER TRANSISTORS L-BAND RADAR APPLICATIONS.

Manufacturers : ST Microelectronics

Image and pinout :

Some of the text within the PDF file :

AM1214-250 RF POWER TRANSISTORS L-BAND RADAR APPLICATIONS TARGET DATA • REFRACTORY /GOLD METALLIZATION • EMITTER SITE BALLASTING • LOW RF THERMAL RESISTANCE • INPUT/OUTPUT MATCHING • OVERLAY GEOMETRY • METAL/CERAMIC HERMETIC PACKAGE • POUT = 300 W MIN. WITH 8.0 dB GAIN • 1215-1400 MHz OPERATION M259 hermetically sealed ORDER CODE AM1214-250 BRANDING XAM1214-250 PIN CONNECTION 1 DESCRIPTION The AM1214-250 is a rugged, Class C common base device designed for new L - Band medium & long pulse radar applications. Minimal amplitude droop over a long pulse of 500 microsec. is guaranteed by a thermal design incorporating an overlay site-ballasted die geometry. 4 3 1. Collector 2. Base 2 3. Emitter 4. Base ABSOLUTE MAXIMUM RATINGS (TCASE = 25°C) Symbol P [ ... ]

AM1214-250 PDF Datasheet Download