Switch circuit and method of switching radio frequency signals
First Claim
1. A method of switching an RF signal comprising:
- generating a voltage substantially negative with respect to ground using a negative voltage generator circuit comprising a charge pump;
generating one or more control signals using an integrated digital logic circuit;
controlling, using the generated one or more control signals, a switch transistor grouping to a switch ON state or a switch OFF state and a shunt transistor grouping to a shunt ON state or a shunt OFF state, wherein the controlling the shunt transistor grouping to the shunt OFF state and the controlling the switch transistor grouping to the switch OFF state is controlled, at least in part, with the substantially negative voltage;
passing the RF signal between a first RF node and a second RF node using the switch transistor grouping comprising stacked switch N-type metal oxide semiconductor field effect transistors (NMOSFETs) in the switch ON state, the stacked switch NMOSFET transistors coupling the RF nodes; and
not shunting the first RF node to ground using the shunt transistor grouping comprising stacked shunt NMOSFET transistors in the shunt OFF state, the stacked shunt NMOSFET transistors coupling the first RF node and ground;
wherein the generatings, the controlling, the passing and the not shunting take place in a single integrated circuit chip.
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Accused Products
Abstract
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. The switching and shunting transistor grouping pairs are controlled by a switching control voltage (SW) and its inverse (SW_). The switching and shunting transistor groupings comprise one or more MOSFET transistors connected together in a “stacked” or serial configuration. The stacking of transistor grouping devices, and associated gate resistors, increase the breakdown voltage across the series connected switch transistors and operate to improve RF switch compression. 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 inventive RF switch provides improvements in insertion loss, switch isolation, and switch compression.
650 Citations
30 Claims
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1. A method of switching an RF signal comprising:
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generating a voltage substantially negative with respect to ground using a negative voltage generator circuit comprising a charge pump; generating one or more control signals using an integrated digital logic circuit; controlling, using the generated one or more control signals, a switch transistor grouping to a switch ON state or a switch OFF state and a shunt transistor grouping to a shunt ON state or a shunt OFF state, wherein the controlling the shunt transistor grouping to the shunt OFF state and the controlling the switch transistor grouping to the switch OFF state is controlled, at least in part, with the substantially negative voltage; passing the RF signal between a first RF node and a second RF node using the switch transistor grouping comprising stacked switch N-type metal oxide semiconductor field effect transistors (NMOSFETs) in the switch ON state, the stacked switch NMOSFET transistors coupling the RF nodes; and not shunting the first RF node to ground using the shunt transistor grouping comprising stacked shunt NMOSFET transistors in the shunt OFF state, the stacked shunt NMOSFET transistors coupling the first RF node and ground; wherein the generatings, the controlling, the passing and the not shunting take place in a single integrated circuit chip. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of switching an RF signal comprising:
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generating a voltage substantially negative with respect to ground using a negative voltage generator circuit comprising a charge pump; generating one or more control signals using an integrated digital logic circuit; controlling, using the generated one or more control signals, a switch transistor grouping to a switch ON state or a switch OFF state and a shunt transistor grouping to a shunt ON state or a shunt OFF state, wherein the controlling the shunt transistor grouping to the shunt OFF state and the controlling the switch transistor grouping to the switch OFF state is controlled, at least in part, with the substantially negative voltage; not passing the RF signal between a first RF node and a second RF node using the switch transistor grouping comprising stacked switch N-type metal oxide semiconductor field effect transistors (NMOSFETs) in the switch OFF state, the stacked switch NMOSFET transistors coupling the RF nodes; shunting the first RF node to ground using the shunt transistor grouping comprising stacked shunt NMOSFET transistors in the shunt ON state, the stacked shunt NMOSFET transistors coupling the first RF node and ground; and wherein the generatings, the controlling, the not passing and the shunting take place in a single integrated chip. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification