| 摘要 |
PURPOSE: A method of manufacturing an antenna is provided to circularly polarize radiation at frequencies above 200 MHz. CONSTITUTION: A method of manufacturing a quadrifilar antenna for circularly polarized radiation at frequencies above 200 MHz, the antenna comprising a plurality of substantially helical conductive radiating tracks(10AR,10BR,10CR,10DR) located on a dielectric substrate, comprises monitoring at least one electrical parameter of the antenna and removing conductive material from at least one of the tracks to bring the monitored parameter nearer to a predetermined value, thereby to increase the inductance of the track. The conductive material is removed from the track by laser etching an aperture in the track, leaving the edges of the track intact on either side of the aperture. |
