This part is a kind of semiconductor called 2SK2973.
Function of this product has RF POWER MOS FET(VHF/UHF power amplifiers).
Manufacturers : Mitsubishi Electric Semiconductor
Image and pinout :
Some of the text within the PDF file :
MITSUBISHI RF POWER MOS FET 2SK2973 DESCRIPTION 2SK2973 is a MOS FET type transistor specifically designed for VHF/UHF power amplifiers applications. OUTLINE DRAWING 4.6MAX 1.6±0.2 Dimensions in mm 1.5±0.1 FEATURES • High power gain:Gpe≥13dB @VDD=9.6V,f=450MHz,Pin=17dBm • High efficiency:55% typ. • Source case type SOT-89 package (connected internally to source) 1 2 3 APPLICATION For drive stage and output stage of power amplifiers in VHF/UHF band portable radio sets. 1.5 0.53 MAX 0.48MAX 1 : DRAIN 2 : SOURCE 3 : GATE 0.4 +0.03 -0.05 3.0 MARKING SOT-89 MARKING TYPE No. K1 LOT No. ABSOLUTE MAXIMUM RATINGS (TC=25˚C, unless otherwise noted) Symbol VDSS VGSS Pch Tj Tstg Parameter Drain to source voltage Gate to source voltage Channel dissipation Junction temperature [ ... ]