This is a 2W RF amplifier circuit build with power MOSFET LF2810A.

Figure A

Figure A is the schematic of the microstrip single stage RF amplifier. The amplifier is based on the M/A-Com LF2810A MOSFET. The transistor is actually a 10 watt, 28 volt part, but provides adequate gain for this application at 12 VDC. The amplifier provides greater than 40% efficiency at the desired output power. Trimmer capacitors are used for input and output matching. Output power is adjusted by a trimpot which sets the gate bias voltage.

Figure B

Figure B is the layout for the microstrip circuit board. The board material is 0.030 inch Duroid. The circuit board is compression soldered onto a similarly sized copper heat spreader. The board and spreader are milled and drilled to accept the flange-mount transistor.

source: http://www.ham-radio.com/wb6zsu/components/exciter/exciter_mods.html