Silicon Ring FET Antenna Array for Tunable THz Polarization Detection
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Solution Overview
Problem
Current terahertz (THz) electromagnetic wave detectors based on field-effect transistors (FETs) face challenges in efficiently detecting THz waves due to limitations in asymmetry and resonant frequency tuning, which affect the sensitivity and specificity of the detection process.
Innovation Solution
The proposed solution involves an antenna device with a silicon substrate featuring first and second type doped regions and gates, where the doped regions and gates are strategically arranged to absorb THz electromagnetic waves, creating an asymmetric structure that enhances electric field distribution and allows for resonant frequency adjustment through external voltage, thereby improving detection sensitivity and specificity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional FET-based THz detector is used, then the device structure is simple, but the detection sensitivity and specificity are limited due to insufficient asymmetry and fixed resonant frequency
Solution Approach 1:
The patent introduces asymmetric doped regions (first doped region and second doped region with different doping types and concentrations) into the FET structure. This asymmetry creates an asymmetric electric field distribution under the gates, which enhances the photoresponse to THz waves and improves detection sensitivity and specificity beyond conventional symmetric FET detectors.
Solution Approach 2:
The patent makes the resonant frequency tunable by applying external voltages to the gates. The resonant frequency can be dynamically adjusted by changing the gate voltages, which modulates the electric field distribution and allows the detector to adapt to different THz frequency bands, overcoming the fixed frequency limitation of conventional detectors.
2Measurement precision
If asymmetric doped regions are introduced to enhance photoresponse, then detection sensitivity improves, but device complexity increases
Solution Approach 1:
The patent applies local quality by creating doped regions with specific doping types and concentrations at particular locations (first doped region near source, second doped region near drain with different doping). This localized asymmetric doping enhances the electric field asymmetry exactly where needed under the gates, maximizing photoresponse while keeping the overall device structure manageable.
Solution Approach 2:
The patent changes the doping parameters (doping type, doping concentration) in different regions to create the desired asymmetry. By carefully controlling these doping parameters, the patent achieves enhanced photoresponse through asymmetric electric field distribution while maintaining a feasible device structure that can be manufactured.
3Measurement precision
If resonant frequency tuning is implemented through external voltage, then detection specificity improves, but device complexity and control requirements increase
Solution Approach 1:
The patent implements dynamic resonant frequency tuning by applying variable voltages to the gates. The resonant frequency can be continuously adjusted by changing the gate voltages, enabling the detector to target specific THz frequency bands. This dynamic control improves detection specificity while using a relatively simple voltage control mechanism.
Solution Approach 2:
The patent changes the electrical parameters (gate voltages) to tune the resonant frequency. By controlling the voltage parameters applied to the gates, the patent achieves frequency-specific detection capability, allowing the same device to detect different THz frequencies by simply adjusting the voltage parameters without physical restructuring.
4Force
If multiple doped regions with different doping types are used, then electric field asymmetry increases, but manufacturing precision requirements increase
Solution Approach 1:
The patent creates locally optimized doped regions with specific doping characteristics (first doped region with first doping type, second doped region with second doping type). This local quality approach allows each region to be optimized for its specific function while maintaining overall asymmetry, making the manufacturing process more manageable by focusing precision requirements on localized areas rather than the entire device.
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 configuration enables sensitive detection of THz waves by maximizing asymmetry and allowing for resonant frequency tuning, leading to enhanced photoresponse and polarization information acquisition, thereby improving the overall detection efficiency and accuracy.
Implementation Method 1
the at least two first doped regions and the second doped region may absorb an electromagnetic wave in a certain frequency band of a terahertz (THz) electromagnetic wave
Implementation Method 2
detect a photoresponse using a direct current (DC) voltage of the drain, which is an output port, by an asymmetric distribution of the electric charges
Implementation Method 3
induce asymmetry in a quantity of electric charges in a lower semiconductor channel region between the source and the drain, detect a photoresponse using a direct current (DC) voltage of the drain
Implementation Method 4
a resonant frequency of the antenna device may be adjusted according to an external voltage applied to the at least two gates
Data Source
AI summary
An antenna device according to an example embodiment includes a silicon substrate of first type doping, at least two first doped regions formed by second type doping different from the first type doping, a second doped region formed by the second type doping outside a channel region surrounding the at least two first doped regions, and at least two gates disposed on a dielectric layer. In the antenna device, a resonant frequency is adjusted according to an external voltage individually applied to the at least two gates, and polarization information of a terahertz (THz) light source is obtained based on a pattern and an amount of an electric field measured at the at least two gates.