A relatively low power feedforward amplifier for 1.9 GHz has been deve
loped to demonstrate the feasibility of the adaptive feedforward linea
rization technique. The saturated two-tone output power of this amplif
ier is approximately 4 W. The measured third-order intermodulation is
-18 dBc before the linearization loop is closed; after the loop is clo
sed, this value is suppressed to -45 dBc. Therefore, the amplifier's i
ntermodulation cancellation performance is greater than 25 dB.