Abstract: A linear antenna switch arm comprising a field effect transistor comprising a source, a drain and a plurality of gates; a signal line connected between source and drain, the signal line comprising at least one signal line resistor; at least one gate being connected to the signal line by a connection line, the join between connection line and signal line comprising a node; the at least one gate being selected from the plurality of gates such that the adjacent gates on each side of the connected gates are not connected to the signal line.

Abstract: A micro-electromechanical variable capacitor with first and second capacitor plates spaced apart to define a gap therebetween. The first plate has two control electrodes and an active electrode. The second plate is movable relative to first plate when a voltage is applied to produce a potential difference across the control electrode and the second capacitor plate. This has the effect of varying the capacitance of the capacitor. The facing surface of at least one of the plates is formed in such a way that it has a roughened surface. The degree of roughness is sufficient to prevent the facing surfaces adhering together through stiction.