摘要 |
A bifunctional antenna of a primary/secondary radar system comprises a reflector having a concave front surface illuminated by a source of primary radiation and formed with a row of circular ports along a horizontal generatrix, the ports lying forwardly of respective cavities or waveguides of cylindrical configuration excitable to emit circularly polarized secondary radiation. In some embodiments the polarization may be changed to a linear or an elliptical mode under the control of inserts rotatable about the cavity axis. |