Belden CDT Electronics Division, which develops specialty cable products for A/V, broadcast and entertainment applications, announced the extension of its SDI coaxial cables' performance specifications from 3 GHz to 4.5 GHz, at NAB--with every reel being sweep-tested for return loss and certified to the new higher frequency. The extension was designed to assure broadcasters, manufacturers and the standards groups of high-performance reliability during the migration from 1080i to 1080p protocols and equipment (which require twice the bandwidth of 1080i).
To date, Belden is believed to be the first cable manufacturer to perform sweep testing and certification to meet the new format. In 1080i, the image resolution is 1920 x 1080 pixels, sent at 60 interlaced fps. In 1080p, the image resolution is the same but is sent at 60 complete fps. As a result, some engineers think progressive images result in better picture quality. And some do not.
