Monostatic radar cross-section spectra of a rotating-fan array, with tilted plate metal blades, in the PO/PTD approximation

The monostatic radar cross-section spectra of a rotating-fan array, with tilted blades, are investigated. The high-frequency theoretical treatment of a slowly rotating and electrically large scatterer is based on the quasi-stationary method with the physical optics/physical theory of diffraction (PO/PTD) technique. Only the theta-theta polarization case is considered here, although the psi-psi polarization case can be treated in the same way. The solution is applicable to any observation angles, and, except for the condition of the same rotational velocity, each fan need not have the same number of blades and dimensions or the same spacing. An example, a linear array with two synchronously rotating fans, each with three identical tilted blades, is presented. The agreement between the theoretical and experimental results is acceptable.