A Broadband Active Van Atta Array System for Monostatic RCS Modulation at X-Band

This letter presents a broadband active Van Atta array system at X -band, which is used for monostatic radar cross section (RCS) modulation and enhancement. The active system mainly consists of two uniform linear arrays (ULAs) and an active four-channel radio frequency (RF) amplifying circuit. By introducing the electrically modulated attenuator (EMA) into the active system, the transmission gain of the proposed four-channel RF amplifying circuit is controlled by a voltage signal from a control circuit and the backscattering field of the system can be sequentially modulated. The system's performance of RCS modulation and retrodirectivity are validated through measurement over a relative bandwidth of 40% centered at 10 GHz. The modulation range of monostatic RCS is generally more than 20 dB at the X -band. Its 3-dB retrodirective range and maximum equivalent RCS are 70°-120° and 1.4-3.9 dBsm varying from 8 to 12 GHz, respectively.