The TRF1108 is a wide-band feedback amplifier with approximately 15.5dB to 18dB of gain (1GHz to 8GHz). When designing with a wide-band RF amplifier with relatively high gain, follow these printed-circuit-board (PCB) layout guidelines to maintain stability and optimized performance:

• Use a multilayer board to maintain signal and power integrity, and thermal performance. The figures in the next section show an example of a good layout.
• Route the RF input and output lines as grounded coplanar waveguide (GCPW) lines. For the second layer, use a continuous ground polygon below the RF traces, and continuous VSS polygon below the amplifier area.
• Match the input differential lines in length to minimize phase imbalance.
• Use small-footprint, passive components wherever possible.
• Connect the ground and VSS planes on the top and internal layers with well-stitched vias.
• Place a thermal via under the device that connects the top thermal pad with VSS planes in the inner layers of the PCB. Also, connect the thermal pad to the top layer VSS plane through the VSS pins for improved heat dissipation.