| 摘要 |
<p>RESISTIVE LOOP ANGULAR FILTER An angular filter (30, 50) for electromagnetic radiation is formed of a set of elements supported on a dielectric substrate. The elements are rods (100) or loops (50) which are electrically conducting and include resistance for dissipating energy of the radiation. Each rod (100) is formed as a linear element parallel to the axis (300) of propagation of the radiation. Each loop element (50) is formed as a closed loop in a plane normal to an axis (40) of propagation of the radiation. This minimizes interaction with a transverse magnetic field of the radiation at zero angle of incidence to the filter, the interaction and consequent attenuation increasing with increasing angle of incidence. Thereby, spurious sidelobes of a radiation pattern associated with a radar or other antenna can be reduced by the filter in favor of the main lobe along the antenna axis. The loop elements (50) may also be formed by a set of members (38) spaced apart to introduce capacitance for resonating with inherent inductance of the members, thereby to enhance the filter attenuation.</p> |
