A semiconductor device comprising a switch, the device having a layout comprising one or more rectangular unit cells, each unit cell comprising: a gate comprising: a substantially cross-shaped part comprising four arms (10, 14) that divide the unit cell into quadrants; and a substantially loop-shaped part, wherein a center of the cross-shaped part is located inside the loop-shaped part, and wherein the loop-shaped part intersects each arm of the cross-shaped part to divide each quadrant into: an inner region located inside the loop-shaped part; and an outer region located outside the loop-shaped part; a substantially loop-shaped active region forming a source and drain of the switch, wherein first and second parts of the loop-shaped active region located in respective first and second diagonally opposite quadrants of the unit cell each include an inner source region located inside the loop-shaped part of the gate and an outer drain region located on an outer side of the loop-shaped part of the gate, wherein third and fourth parts of the loop-shaped active region located in respective third and fourth diagonally opposite quadrants of the unit cell each include an inner drain region located inside the loop-shaped part of the gate and an outer source region located on an outer side of the loop-shaped part of the gate; and a plurality of connection members extending over the gate, source and drain for providing electrical connections to the source and drain. a gate comprising: a substantially cross-shaped part comprising four arms (10, 14) that divide the unit cell into quadrants; and a substantially loop-shaped part, wherein a center of the cross-shaped part is located inside the loop-shaped part, and wherein the loop-shaped part intersects each arm of the cross-shaped part to divide each quadrant into: an inner region located inside the loop-shaped part; and an outer region located outside the loop-shaped part; a substantially cross-shaped part comprising four arms (10, 14) that divide the unit cell into quadrants; and a substantially loop-shaped part, wherein a center of the cross-shaped part is located inside the loop-shaped part, and wherein the loop-shaped part intersects each arm of the cross-shaped part to divide each quadrant into: an inner region located inside the loop-shaped part; and an outer region located outside the loop-shaped part; an inner region located inside the loop-shaped part; and an outer region located outside the loop-shaped part; a substantially loop-shaped active region forming a source and drain of the switch, wherein first and second parts of the loop-shaped active region located in respective first and second diagonally opposite quadrants of the unit cell each include an inner source region located inside the loop-shaped part of the gate and an outer drain region located on an outer side of the loop-shaped part of the gate, wherein third and fourth parts of the loop-shaped active region located in respective third and fourth diagonally opposite quadrants of the unit cell each include an inner drain region located inside the loop-shaped part of the gate and an outer source region located on an outer side of the loop-shaped part of the gate; and a plurality of connection members extending over the gate, source and drain for providing electrical connections to the source and drain.