Development of an Effective Feed-Forward Control Method for Active Antenna Cancelation

Electromagnetic compatibility problems have become more important with the increasing number of antennae integrated into a single communication platform. Traditional methods based on adaptive interference cancelation (AIC) systems have been widely adopted for removing electromagnetic interferences. Usually, these methods may have lower interference cancelation ratio (ICR) since the AIC gain is finite. For overcoming this problem, a feed-forward control method can be used to significantly increase the ICR value by feeding the proper interference signal to the residual error signal. In this paper, a feed-forward control method based on analog adaptive interference cancelation (FAAIC) system has been developed and its corresponding time-domain characteristics of “weights” and “residue error” have been comprehensively studied. The optimal coefficients for feed-forward control have been obtained with the relation of the null shifts of the correlators. The influence of null shifts to feed-forward control is also analyzed. Compared with a traditional analog adaptive interference cancelation system, the average convergence speed of FAAIC is the same and the effect of interference cancelation can be improved remarkably. The experimental results have demonstrated the feasibility of the developed FAAIC system.