Van Atta Array Tag for Millimeter-Wave Positioning
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Solution Overview
Problem
Current position measurement technologies for Beyond-5G systems face challenges in efficiently determining the positions of a large number of objects with low power consumption, especially in environments where clutter noise is prevalent, such as in the millimeter-wave band.
Innovation Solution
A position measurement system utilizing a tag with a planar Van Atta array antenna and an FSK modulator, which performs frequency-shift keying modulation on interrogation signals, and an interrogator that outputs continuous unit chirp signals to improve signal-to-noise ratio and accurately measure tag positions, enabling low-power communication and precise positioning of multiple tags.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional position measurement technologies are used in millimeter-wave band, then position measurement can be performed, but power consumption increases and measurement precision deteriorates in environments with clutter noise
Solution Approach 1:
The tag uses passive backscatter modulation to communicate position information without its own power source. The FSK modulator modulates the reflected interrogation signal based on position data, allowing the tag to serve itself by harvesting energy from the incoming signal and transmitting position information through reflection patterns, eliminating the need for active power consumption at the tag side
Solution Approach 2:
The patent replaces active transmitters with passive backscatter reflection. Instead of using mechanical or electronic power-consuming transmitters at the tag, the system uses electromagnetic wave reflection with FSK modulation to convey position information, substituting an active transmission system with a passive reflection-based system
2Measurement precision
If conventional position measurement technologies are used, then position data can be obtained, but measurement precision deteriorates in environments with clutter noise
Solution Approach 1:
The patent converts the harmful effect of clutter noise into a beneficial signal characteristic. By using FSK modulation on the backscattered signal, the system encodes position information in frequency shifts that can be distinguished from clutter noise through frequency-domain analysis, transforming the noisy environment into a usable signal source
Solution Approach 2:
The patent changes the frequency parameter of the backscattered signal through FSK modulation to encode position information. The FSK modulator varies the frequency of the reflected signal based on position data, allowing the receiver to extract position information by detecting frequency shifts rather than relying on signal amplitude or timing alone, which are more susceptible to clutter noise
3Measurement precision
If FSK modulation is implemented, then power consumption is reduced and position measurement precision is improved, but device complexity increases
Solution Approach 1:
The FSK modulator in the tag serves multiple functions: it modulates the backscattered signal to encode position information, enables frequency-shift keying for noise resistance, and allows passive operation without additional power consumption. This multi-functionality reduces the need for separate components for each function, thereby limiting the increase in device complexity
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
The system achieves sub-centimeter accuracy in position measurement for multiple tags, even in complex environments, by effectively separating clutter noise and backscattered signals, and reduces power loss and implementation costs through FSK modulation and Van Atta array retroreflection.
Implementation Method 1
a planar Van Atta array antenna
Implementation Method 2
a frequency-shift keying (FSK) modulator connected to the planar Van Atta array antenna
Data Source
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AI summary
Provided are a tag, interrogator, and system for performing position measurement based on backscatter in a millimeter-wave band. In detail, provided is a tag including a planar Van Atta array antenna, a frequency-shift keying (FSK) modulator connected to the planar Van Atta array antenna, and at least one bias circuit connected to the FSK modulator, wherein the FSK modulator is configured to, based on an interrogation signal being received by the planar Van Atta array antenna, modulate the interrogation signal based on a control signal supplied through the at least one bias circuit, and output the modulated interrogation signal in a direction from which the interrogation signal is received, through the planar Van Atta array antenna.