| 摘要 |
<p>Antennae supporting strips of material of contrasting dielectric characteristics for receiving or transmitting electromagnetic signals of a few millimetres wavelength are provided with ancillary strips or patches of similar material which act as reflectors to boost the efficiency and directionality of the primary aerial strips. Pref. the ancillary patches are located at a distance of 8-20 x the signal wavelength away from the primary strips and along the same axis. The ancillary strips are shorter than and parallel to the prim. strips and approx. 3 wavelengths away. Claims include antennae with strips/patches of PTFE carried on and flush with the surface of a metallic body, or vice versa. An example antenna for a cylindrical missile nose of approx. 100 mm dia. operating on a 70 GHz signal involved use of PTFE strips of approx. 5 x a mm cross-section, to obtain a signal gain of approx. 6 dB.</p> |
