The semiconductor device includes a first semiconductor region made from n-conducting SiC and a second semiconductor region made from p-conducting SiC. An adjustment assembly is provided for adjusting the radius of curvature of the path of motion of the backrest. A second insulating layer is provided on top of the first insulating layer in the periphery of the top portion of the first electrode portion; the second insulting layer is located slightly apart from the top portion of the first electrode portion. The controller tracks the bank address, and may issue one or more memory access commands while a DARF operation is being performed, if the memory access and the refresh are directed to different banks. Also, the CS measurements may be high-pass filtered to attenuate background light variation. The communication system comprises a plurality of communicating nodes.