摘要 |
<p>An antenna comprising a photoconductive material (61) and a plurality of spaced apart electrodes (69, 71) provided on said photoconductive material (61), each electrode (69, 71) having at least one facing edge which faces a facing edge of an adjacent electrode, a physical barrier (67) being provided abutting a facing edge of at least one electrode (69, 71), said barrier (67) extending to at least the full height of said facing edge.</p> |