Common antenna for primary and secondary radar - uses totally integrated radiating waveguides generating linearly, circularly or elliptically polarised waves

摘要

The reflector is constructed of metallic or dielectric (epoxy impregnated glass mat) material covered with a fabric of glass fibres carrying crossed braided metallic wires generally of thin copper. The radiating elements totally integrated with the reflector are polarising circular waveguides of the same material, in each of which the polariser is free to rotate about its longitudinal axis (delta). The polariser is either a plane network of parallel metallic sheets or several networks associated with parallel metallic wires, the number and spacing of the networks allowing for adjustment of the bandwidth. Plunger or crossbar exciters project into each waveguide from coaxial adaptors and cables connected to a power divider at the rear of the reflector. When the sec. radar function possesses an indicator channel the latter may be equipped with supplementary backward-radiating waveguides.