Abstract:
Data-cable systems are essential for an evolving Square Kilometre Array (SKA) phasedarray
demonstrator project. Loss, dispersion and channel coupling are the characteristics of interest.
We evaluate a Category 7 (CAT-7) cable system, which incorporates a 20 m CAT-7 cable, balun
transformers, and ARJ45 connectors. Measurements from 30 MHz - 1.5 GHz are made using a
calibrated Vector Network Analyzer (VNA). Through, Reflect, Line (TRL) as well as Short, Open,
matched Load, Through (SOLT) calibration techniques were performed, which separately test the
cables and the entire system performance respectively. A further measurement isolates the baluns.
The connectors and baluns are mounted on customised printed circuit boards. We investigated phase
dispersion, return loss, attenuation, near-end crosstalk (NEXT) and far-end crosstalk (FEXT). The
best system was found to have a linear phase response in the 30 MHz to 1.4 GHz band, with NEXT
and FEXT levels below -50 dB and -63 dB respectively. Such performance makes this cable class a
candidate for high-volume data streams anticipated for the SKA.
