A design of broadband active decoy based on FPGA array was presented to meet the requirements of effective active decoys against modern radars. Firstly, the sensitivity and emitting power of the decoy was settled, then modularization method was adopted and 12bit high speed DRFM modules was used to build an active decoy whose working bandwidth ranks 1GHz level. Experiment results showed the decoy meet the requirements of broad working bandwidth, signal characteristics etc.