Charge-Coupled Amplifier Biasing via Quantum Gate Tunneling
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Solution Overview
Problem
Implementing low noise signal amplifiers for very small signals in low bandwidth applications on silicon chips is challenging due to the need for impractically large capacitors or resistors, which are not feasible for silicon chip integration.
Innovation Solution
The use of quantum gate tunneling in semiconductor circuits to define the DC state of charge-coupled amplifiers, allowing for bipolar tunneling currents and controlled common mode voltages without additional elements, enabling efficient DC voltage definition without high-value resistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If large capacitance values are used to achieve low-frequency operation, then low-frequency signal passing capability is improved, but device complexity and chip integration feasibility deteriorate
Solution Approach 1:
The patent changes the physical parameters of the transistor gate oxide layer to enable quantum tunneling current flow. By adjusting the gate oxide thickness to a specific range (5-20 nm), the system enables low-frequency operation without requiring large external capacitors, thus resolving the contradiction between low-frequency capability and device size.
Solution Approach 2:
The patent replaces the traditional mechanical/electrical capacitor-based frequency filtering mechanism with a quantum mechanical tunneling effect. The quantum tunneling current through the gate oxide layer inherently provides the low-frequency signal passing capability without requiring physical capacitor components, thereby reducing device complexity.
2Measurement precision
If high-value resistors are used to define DC state, then DC voltage definition capability is improved, but noise level increases
Solution Approach 1:
The patent replaces the traditional resistor-based DC voltage definition mechanism with a quantum mechanical tunneling effect. The quantum tunneling current through the gate oxide layer provides a low-noise pathway to define the DC state, eliminating the need for high-value resistors that generate thermal noise.
Solution Approach 2:
The gate oxide layer acts as an intermediary element that enables DC voltage definition through quantum tunneling. This intermediary mechanism provides a controlled current path that defines the DC state without requiring high-value resistors, thus reducing noise while maintaining DC definition capability.
3Ease of operation
If additional control elements are added to enable bipolar tunneling current, then DC state control capability is improved, but device complexity increases
Solution Approach 1:
The patent makes the gate oxide layer a multi-functional element that simultaneously enables bipolar tunneling current flow and provides DC state control capability. By configuring the gate oxide thickness and transistor structure, a single element performs multiple functions without requiring additional control components, thus improving ease of operation while maintaining simplicity.
Solution Approach 2:
The patent merges the DC state control function with the existing transistor gate structure. The gate oxide layer is integrated into the transistor fabrication process, combining the control element function with the existing device architecture, thereby enabling bipolar tunneling current control without adding separate control elements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows charge-coupled amplifiers to operate with defined DC states without large capacitors or resistors, reducing noise and enabling low-frequency operation on silicon chips, improving the feasibility of signal processing for small signals.
Implementation Method 1
gate oxide layers on the PMOS and NMOS transistors are of a thickness such that current is able to flow through the gate oxide from a channel beneath the gate oxide
Data Source
AI summary
An apparatus and method for using the known phenomena of quantum gate tunneling in semiconductor transistors to define the DC state of a charge-coupled amplifier is described. A first stage in which the tunneling current is bipolar (by pairing PMOS and NMOS transistors) in combination with a second stage with a controlled common mode voltage that can be used to control the first stage tunneling current, and thus the common mode voltage at the input. This can be done without the use of additional elements that may degrade performance or power consumption, since the input devices both process the input signal and maintain the DC operating point of the circuit. The approach may be advantageously used not only in charge-coupled amplifiers as described herein, but also in other capacitively coupled circuits such as charge balancing analog to digital converters (ADCs) and digital to analog converters (DACs).