TRF0208-SP is a wide-band, voltage-feedback amplifier with approximately 16dB of gain. When designing with a wide-band RF amplifier with relatively high gain, make sure to take certain board layout precautions to maintain stability and optimized performance. Use a multilayer board to maintain signal and power integrity and thermal performance. Figure 7-5 shows an example of a good layout. In this figure, only the top layer is shown.

Route the RF input and output lines as grounded coplanar waveguide (GCPW) lines. For the second layer, use a continuous ground layer without any ground-cuts near the amplifier area. Match the output differential lines in length to minimize phase imbalance. Use small footprint passive components wherever possible. Also take care of the input side layout. Use a 50Ω line for the INP routing, and make sure the termination on INM pin has low parasitics by placing the ac-coupling capacitor and the 50Ω resistor very close to the device. Use an RF-quality, 50Ω resistor for termination. Ensure that the ground planes on the top and internal layers are well stitched with vias.

Place thermal vias under the device that connect the top thermal pad with ground planes in the inner layers of the PCB. For improved heat dissipation, connect the thermal pad to the top layer ground plane through the ground pins (see the Layout Example in the next section).