The TRF1108 is a
wide-band feedback amplifier with approximately 15.5dB of gain. 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
PCB. Also, connect the thermal pad to the top layer VSS plane through the VSS
pins for improved heat dissipation.