Method and apparatus for use in improving linearity of MOSFETs using an accumulated charge sink
First Claim
1. An RF switch circuit for switching RF signals, comprising:
- a) an RF input port receiving an RF input signal;
b) an RF output port;
c) a switch transistor grouping having a first node coupled to the RF input port and a second node coupled to the RF output port, wherein the switch transistor grouping is controlled by a first switch control signal (C1); and
d) a shunt transistor grouping having a first node coupled to the RF input port and a second node coupled to ground, wherein the shunt transistor grouping is controlled by a second switch control signal (C1x), and wherein the shunt transistor grouping comprises one or more ACC MOSFETs;
wherein each ACC MOSFET includes a floating body and wherein the ACC MOSFET is biased to selectively operate in the accumulated charge regime, and wherein accumulated charge is present in the body of the floating body MOSFET when the MOSFET is biased to operate in the accumulated charge regime; and
wherein the ACC MOSFET further includes an accumulated charge sink (ACS) operatively coupled to the body of the MOSFET, and wherein, when the MOSFET is operated in the accumulated charge regime, an ACS bias voltage (VACS) is applied to the ACS to control the accumulated charge in the MOSFET body or to remove the accumulated charge from the MOSFET body via the ACS;
and wherein when the first switch control signal C1 is enabled, the switch transistor grouping is enabled and the shunt transistor grouping is disabled thereby passing the RF input signal through to the RF output port, and wherein when the second switch control signal C1x is enabled, the shunt transistor grouping is enabled while the switch transistor grouping is disabled thereby shunting the RF input signal to ground.
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Accused Products
Abstract
A method and apparatus for use in improving the linearity characteristics of MOSFET devices using an accumulated charge sink (ACS) are disclosed. The method and apparatus are adapted to remove, reduce, or otherwise control accumulated charge in SOI MOSFETs, thereby yielding improvements in FET performance characteristics. In one exemplary embodiment, a circuit having at least one SOI MOSFET is configured to operate in an accumulated charge regime. An accumulated charge sink, operatively coupled to the body of the SOI MOSFET, eliminates, removes or otherwise controls accumulated charge when the FET is operated in the accumulated charge regime, thereby reducing the nonlinearity of the parasitic off-state source-to-drain capacitance of the SOI MOSFET. In RF switch circuits implemented with the improved SOI MOSFET devices, harmonic and intermodulation distortion is reduced by removing or otherwise controlling the accumulated charge when the SOI MOSFET operates in an accumulated charge regime.
177 Citations
52 Claims
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1. An RF switch circuit for switching RF signals, comprising:
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a) an RF input port receiving an RF input signal; b) an RF output port; c) a switch transistor grouping having a first node coupled to the RF input port and a second node coupled to the RF output port, wherein the switch transistor grouping is controlled by a first switch control signal (C1); and d) a shunt transistor grouping having a first node coupled to the RF input port and a second node coupled to ground, wherein the shunt transistor grouping is controlled by a second switch control signal (C1x), and wherein the shunt transistor grouping comprises one or more ACC MOSFETs;
wherein each ACC MOSFET includes a floating body and wherein the ACC MOSFET is biased to selectively operate in the accumulated charge regime, and wherein accumulated charge is present in the body of the floating body MOSFET when the MOSFET is biased to operate in the accumulated charge regime; and
wherein the ACC MOSFET further includes an accumulated charge sink (ACS) operatively coupled to the body of the MOSFET, and wherein, when the MOSFET is operated in the accumulated charge regime, an ACS bias voltage (VACS) is applied to the ACS to control the accumulated charge in the MOSFET body or to remove the accumulated charge from the MOSFET body via the ACS;and wherein when the first switch control signal C1 is enabled, the switch transistor grouping is enabled and the shunt transistor grouping is disabled thereby passing the RF input signal through to the RF output port, and wherein when the second switch control signal C1x is enabled, the shunt transistor grouping is enabled while the switch transistor grouping is disabled thereby shunting the RF input signal to ground. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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Specification