Sensitivity of distortion cancellation in feedforward amplifiers to loop imbalances

The sensitivity of distortion cancellation in feedforward amplifiers to amplitude and phase imbalance is investigated. Some workers have suggested that the amplifier is more sensitive to imbalance in signal cancellation loop. It is shown here that this is not true in general. It can become more sensitive to imbalance in either cancellation loop depending on their level of cancellation. Results of a feedforward amplifier simulation are presented to confirm this finding.