A 4-layer PCB with a solid ground plane and a separate power plane is recommended. Keep the RF traces short and away from the digital lines. Use a common mode filter or a Pi-filter to reduce EMI.
Optimize the output power and efficiency by adjusting the bias voltage, output matching network, and load impedance. Use a load-pull analysis to find the optimal load impedance for maximum power and efficiency.
For high-power applications, a heat sink with a thermal conductivity of at least 1 W/m-K is recommended. Ensure good thermal contact between the device and the heat sink using a thermal interface material.
Prevent oscillations by ensuring a stable DC bias, using a low-pass filter at the output, and adding a series resistor to the gate of the transistor. Also, ensure the PCB layout is well-designed to minimize parasitic inductances and capacitances.
The maximum safe operating temperature for the BLF878,112 is 150°C. Ensure the device is operated within the recommended temperature range to prevent thermal damage.
BLF878,112 datasheet
by NXP Semiconductors
