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US 2019/0379330 A1Published application
Body Tie Optimization for Stacked Transistor Amplifier
AssigneepSemi Corporation
InventorsSimon Edward Willard, Chris Olson, Tero Tapio Ranta
Life of this patent
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Abstract
A transistor stack can include a combination of floating and body tied devices. Improved performance of the RF amplifier can be obtained by using a single body tied device as the input transistor of the stack, or as the output transistor of the stack, while other transistors of the stack are floating transistors. Transient response of the RF amplifier can be improved by using all body tied devices in the stack.
Claims32
A circuital arrangement comprising:
- a transistor stack configured to operate as a radio frequency (RF) amplifier, the transistor stack comprising a plurality of stacked transistors comprising an input transistor for receiving an input RF signal to the amplifier, and an output transistor for outputting an output RF signal that is an amplified version of the input RF signal;
- the transistor stack configured to operate between a supply voltage coupled to the output transistor and a reference voltage coupled to the input transistor;
- one or more gate capacitors each connected between a gate of a transistor of the plurality of stacked transistors, except the input transistor, and a reference ground, wherein the each gate capacitor is configured to allow a gate voltage at the gate to vary along with a radio frequency (RF) voltage at a drain of the transistor,
- wherein at least one transistor of the plurality of stacked transistors is a four-terminal transistor having a body and a source, wherein the body is coupled to the source, and
- wherein at least one transistor of the plurality of stacked transistors is a three-terminal transistor.
2 more elements
A method for manufacturing a radio frequency (RF) amplifier, the method comprising:
- providing a substrate comprising one of:
- a) silicon-on-insulator substrate, and b) a silicon-on-sapphire substrate;
- and
- manufacturing, on the substrate, a transistor stack configured to operate as a radio frequency (RF) amplifier, the transistor stack comprising:
- a plurality of series connected transistors comprising at least one four-terminal transistor and at least one three-terminal transistor;
- and
- one or more gate capacitors each connected between a gate of a transistor of the plurality of series connected transistors, except an input transistor, and a reference ground, wherein the each gate capacitor is configured to allow a gate voltage at the gate to vary along with a radio frequency (RF) voltage at a drain of the transistor,
- wherein the least one four-terminal transistor has a body and a source, wherein the body is coupled to the source, the at least one four-terminal transistor comprising the input transistor.
5 more elements
A method for improving a performance of a radio frequency (RF) amplifier, the method comprising:
- providing a plurality of floating body devices;
- configuring the plurality of floating body devices as a cascoded stack comprising an input floating body device and cascode floating body devices;
- coupling gate capacitors between gates of the cascode floating body devices and a reference ground, the gate capacitors configured to allow gate voltages at said gates to vary along with radio frequency (RF) voltages at drains of the cascode floating body devices;
- based on the configuring and the coupling, obtaining an RF amplifier having a characteristic performance;
- replacing, in the cascoded stack, at least one floating body device of the plurality of floating body devices with a body tied device while leaving at least one of the plurality of floating body devices in the cascoded stack, the at least one floating body device comprising the input transistor, wherein a body of the body tied device is coupled to a source of the body tied device;
- based on the replacing, obtaining an RF amplifier having an improved characteristic performance;
- and
- fabricating the RF amplifier with improved characteristic performance on one of:
- a) silicon-on-insulator (SOI) technology, and b) silicon-on-sapphire technology (SOS).
6 more elements
A method for reducing a stack height of an RF amplifier, the method comprising:
- providing a level of a voltage across a stack;
- providing a withstand voltage capability of a three-terminal device;
- based on the level of the voltage and the withstand voltage capability, determining a height of the stack based on a required number of series connected three-terminal devices in the stack;
- replacing at least one device of the series-connected three-terminal devices with a four-terminal device while leaving at least one of the series connected three-terminal devices in the stack, the at least one device comprising an input transistor of the stack, wherein a body of the four-terminal device is coupled to a source of the four-terminal device;
- based on the replacing, reducing the height of the stack;
- and
- fabricating the RF amplifier with reduced stack height on one of:
- a) silicon-on-insulator (SOI) technology, and b) silicon-on-sapphire technology (SOS),
- wherein the fabricating includes coupling of gate capacitors between gates of transistors of the stack and a reference ground, the gate capacitors configured to allow gate voltages at said gates to vary along with radio frequency (RF) voltages at drains of said transistors.
6 more elements
Dependencies are inferred from the claim text.