Abstract:The scattering cancellation design of a conformal array antenna is investigated, and the radiation and scattering modes of a con-formal microstrip antenna is analyzed by characteristic mode theory. The new microstrip antenna structure loaded with parasitic patches is designed which is realizing the independent regulation of the radiation and scattering modes of the conformal cell. The phase of the scattering pattern of the conformal unit is regulated by adjusting the length of the parasitic patch branches, so that the scattering pattern currents of the reference unit and the design unit are in the opposite direction, and the radiation pattern can re-main unchanged. The 4×4 conformal array antenna will be composed of the reference cell and the designed cell to realize the RCS reduction through the scattering cancellation of the two types cells. Simulation results show that the gain reduction of the proposed conformal array is less than 0.1 dB within the operating band 5.09~5.89 GHz, and the RCS reduction is achieved within the 4~8 GHz band. The mean value of the RCS reduction of the in-band x-polarization is 19.4 dB and the peak value of the RCS reduction reaches 21.8 dB. Compared with the traditional scattering cancellation design method used in planar microstrip array antennas, the scattering cancellation method for conformal array antenna is based on characteristic mode theory. The phase of scattering modes of the conformal units and the spatial phase difference is both taken into consideration, which provided a new design method for accurately guiding the conformal array antenna.
