This is a 2W RF amplifier circuit build with single power MOSFET LF2810A.
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 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.
LF2810A is a RF Power MOSFET Transistor 10W, 500-1000MHz, 28V.
- N-Channel enhancement mode device
- DMOS structure
- Lower capacitances for broadband operation
- Common source configuration
- Lower noise floor
- Applications – Broadband linear operation 500 MHz to 1200 MHz
Download LF2810A RF Power MOSFET Datasheet: