A novel and useful RF switch that comprises four transistors configured to have four operating states, wherein at any time at most one transistor is in ‘on’ state. The switch is an on-chip switch and is constructed in using CMOS processes and technology. The switch is optionally a double pole, double throw (DPDT) switch. The switch can be used in numerous mobile devices such as a cellular phone or in the handset or base station of a cordless phone. The switch optionally selects between two antennas and between transmitter and receiver circuits. Within the switch, at least one of the at least four transistors is optionally an N-channel Metal Oxide Semiconductor (NMOS) transistor. The switch can further comprise one or more logic control circuits providing biasing voltages to one or more of the transistors. Within the switch, the control circuit comprises logic components for providing appropriate biasing voltages to the drain, source and gate terminals of the transistors in the switch.