This part is a kind of semiconductor called STA-5063Z.

Function of this product has general purpose class A linear amplifier.

Manufacturers : RF Micro Devices

Image and pinout :

Some of the text within the PDF file :

STA-5063Z 3.3GHz to 6.2GHz General Purpose 3.3V 15 dBm Amplifier STA-5063Z 3.3GHz to 6.2GHz GENERAL PURPOSE 3.3V 15dBm AMPLIFIER Package: SOT-363, 2.0mmx2.1mm Product Description RFMD’s STA-5063Z is a general purpose class A linear amplifier which utilizes InGaP GaAs Heterojunction Bipolar Transistor (HBT) amplifier housed in a low-cost surface- mountable plastic package. This product is specifically designed as a driver amplifier for WLAN 802.11a and 5.8GHz ISM band and 3.3GHz to 3.8GHz fixed wireless applications. It can run from a fixed 3.0V to 3.6V supply with its on chip active bias network which includes a power up and down control. On-chip impedance matching circuitry provides a 50 nominal RF input and output impedance. Its high linearity makes it an ideal choice for [ ... ]

STA-5063Z PDF Datasheet Download