Sparse MIMO Antenna Layout for Faster Millimeter-Wave Body Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing human body security inspection technologies face challenges with high antenna resource utilization, low image quality, and slow image reconstruction due to the need for numerous antennas and inefficient algorithms, particularly at higher frequencies.
Innovation Solution
A sparse multiple-input multiple-output (MIMO) antenna array arrangement with a unique layout and Fourier transform-based synthetic aperture holographic algorithm, reducing the number of antennas and utilizing a sparse design to improve data acquisition speed and reconstruction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If one-dimensional single-transmit single-receive or quasi single-transmit single-receive linear array synthetic aperture imaging principle is used, then imaging can be achieved, but the number of antenna resources required is huge and utilization rate is very low
Solution Approach 1:
The patent divides the antenna array into multiple sections (first section, second section, third section) with different antenna configurations. Each section processes different spatial regions, allowing the system to achieve comprehensive imaging coverage with fewer total antennas by segmenting the detection space and assigning specialized antenna groups to each segment.
Solution Approach 2:
The patent transitions from one-dimensional linear array arrangements to two-dimensional planar array configurations. By adding spatial dimensionality with multiple rows and columns of antennas arranged in a plane, the system achieves better spatial sampling and imaging performance without requiring a proportional increase in the total number of antenna elements compared to extended one-dimensional arrays.
2Measurement precision
If antenna array requires large number of antenna units with half-wavelength spacing, then imaging quality can be maintained, but physical implementation difficulty increases gradually as operating frequency increases
Solution Approach 1:
The patent applies different antenna spacing strategies to different spatial regions and frequency bands. In certain regions where imaging requirements are less stringent or where redundancy can be achieved through signal processing, the antenna spacing can be relaxed beyond the strict half-wavelength requirement. This allows the system to maintain overall imaging quality while reducing the number of antennas needed in specific areas, thereby easing manufacturing complexity at high frequencies.
Solution Approach 2:
The patent employs adaptive antenna spacing that varies with operating frequency. At higher frequencies where manufacturing difficulty increases, the system dynamically adjusts the effective sampling density through signal processing techniques and adaptive beamforming, allowing physical antenna spacing to be larger than the conventional half-wavelength while maintaining imaging quality through computational compensation.
3Device complexity
If sparsely distributed multiple-input multiple-output antenna layout is used, then number of antennas is reduced, but distance between equivalent phase center and transmitting-receiving antennas is relatively large requiring backward projection algorithm which has slow calculation speed
Solution Approach 1:
The patent implements dynamic beamforming and signal processing techniques that adapt to the sparse antenna configuration. By dynamically adjusting beam weights, phases, and focusing parameters based on real-time signal characteristics and target positions, the system compensates for the larger distances between equivalent phase centers and antennas. This dynamic adaptation enables the use of faster Fourier transform-based reconstruction algorithms instead of slow backward projection methods, thereby maintaining high reconstruction speed despite the sparse antenna layout.
Solution Approach 2:
The patent replaces traditional mechanical or geometric approaches to achieving dense antenna sampling with computational methods. Instead of physically placing antennas at half-wavelength intervals and using straightforward geometric reconstruction, the system uses sparse array signal processing, compressed sensing, and Fourier transform techniques to achieve equivalent or superior imaging performance with fewer antennas and faster reconstruction speeds.
4Quantity of substance
If transmit-receive integrated antenna array is used, then N antenna units are required for N equivalent elements, but utilization rate of transmitting and receiving antennas is very low
Solution Approach 1:
The patent designs antenna elements that can function as both transmitting and receiving antennas (transceivers), allowing each antenna unit to perform multiple roles. By configuring antennas to operate in transmit mode, receive mode, or both modes depending on the operational requirements, the system achieves N equivalent elements with fewer than N dedicated antenna units, thereby improving the utilization rate and reducing the total number of antenna elements needed.
Solution Approach 2:
The patent merges the transmitting and receiving antenna functions into unified transceiver units. Instead of having separate transmit and receive antenna arrays that each require full complement of elements, the system combines both functions into shared antenna elements with appropriate switching and signal processing, achieving the same imaging capability with reduced antenna count and improved resource utilization.
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 solution achieves faster scanning and clearer imaging with reduced hardware complexity and cost, enabling efficient high-frequency millimeter wave security inspection.
Implementation Method 1
a first set of transmitting antennas and a second set of transmitting antennas, each set including a plurality of transmitting antennas arranged along the first direction; the set of receiving antennas includes a plurality of receiving antennas arranged along the first direction such that an arrangement direction of the set of receiving antennas is parallel to an arrangement direction of the first set of transmitting antennas and an arrangement direction of the second set of transmitting antennas
Data Source
Figure 1~3
Figure 4
Figure 5~7
AI summary
Embodiments of the present disclosure provide a sparse multiple-input multiple-output array arrangement for active millimeter wave security inspection imaging, a human body security inspection apparatus, and a human body security inspection method. The sparse multiple-input multiple-output array arrangement includes two sets of transmitting antennas and a set of receiving antennas. The two sets of transmitting antennas include first and second sets of transmitting antennas, each set of transmitting antennas including a plurality of transmitting antennas arranged along a first direction. The set of receiving antennas includes a plurality of receiving antennas also arranged along the first direction and coplanar with the first and second sets of transmitting antennas, and is located between the first and second sets of transmitting antennas in a second direction perpendicular to the first direction.