A novel RF switch circuit and method for switching RF signals is
described. The RF switch circuit is fabricated in a silicon-on-insulator
(SOI) technology. The RF switch includes pairs of switching and shunting
transistor groupings used to alternatively couple RF input signals to a
common RF node. A fully integrated RF switch is described including
digital control logic and a negative voltage generator integrated
together with the RF switch elements. In one embodiment, the fully
integrated RF switch includes a built-in oscillator, a charge pump
circuit, CMOS logic circuitry, level-shifting and voltage divider
circuits, and an RF buffer circuit. Several embodiments of the charge
pump, level shifting, voltage divider, and RF buffer circuits are
described. The RF switch provides improvements in insertion loss, switch
isolation, and switch compression. An improved voltage reducing circuit
is described. The improved voltage reducing circuit limits voltages
applied to selected nodes within the integrated circuit.