Abstract Presently, Radar Target Simulator (RTS) has become a key instrument in the research and development process of automotive millimeter-wave radar. However, amplitude-phase distortion resulting from non-ideal electronic components can impact its accuracy simulating real traffic targets. This paper analyzes individual effects amplitude phase on range profile simulated targets RTS. Results be used for design RTS systems.

Abstract This manuscript addresses the challenge of imaging artifacts in millimeter-wave (MMW) systems caused by concave structures due to multiple internal reflections. We introduce an modified linear aperture technique specifically designed for structures, which effectively suppresses high-order scattering and achieves precise reconstruction multi-reflection signals. Unlike previous cylindrical measurement methods, this approach does not require dihedral cavity be placed a specific...

Abstract Nonlinear calibration of probe frequency response is a common problem in near-field measurement. In this paper, we present an over-the-air(OTA) technique for measurements, predicated on our proposed measurement model. A detailed discussion provided the use metal sphere, plane, and innovative dihedral calibrators, which exhibit scattering properties analogous to those point target. The effectiveness validated through both full-wave simulation experiment. method ensures consistency...

Abstract Accurate radar cross section (RCS) measurements are challenged by background-target coupling, such as interactions with the ground or support structures. This paper introduces a method using three-dimensional (3D) imaging to isolate and measure target scattering characteristics. By utilizing high-resolution 3D algorithms, separates target’s scatterers from background noise, enhancing RCS measurement accuracy. Experimental results show this approach reduces coupling effects,...

Radar target near-field scattering characteristics are essential for the identification of properties and improvement recognition. Nevertheless, efficiency current precision three-dimensional (3D) imaging algorithms in measurements is restricted by their substantial computational complexity. To resolve this matter, we propose a hybrid 3D algorithm that optimized cylindrical sampling operates both wavenumber domain time (WDTD). Wavenumber initially utilized rapid localization strong sources....

A Ka-band 1024-channel passive millimeter wave (PMMW) imager with 1 GHz bandwidth called BHU-1024 has been developed by Beihang University for security screening. uses linear phased array to obtain resolution in the horizontal direction and aperture synthesis vertical direction. The non-ideal characteristics of hardware cause decrease system sensitivity always blur reconstructed image, hampering applications where high accurate recognition are emphasized. Hence, effective calibration is a...

A Ka-band 1024-channel passive millimeter wave (PMMW) imager (BHU-1024) based on synthetic aperture interferometric radiometer (SAIR) technique has been developed by Beihang University for security screening. BHU-1024 uses linear phased array to obtain resolution in the horizontal direction and synthesis vertical direction. This is designed detecting concealed weapons human body operated under near-field condition of antenna array. Thus, conventional direct Fourier imaging theory, which...

Millimeter-wave (MMW) imaging is becoming an important option in many sensing applications. However, the resulting images are often plagued with artifacts caused by complex target scenarios such as concave structures, hampering applications where precise recognition emphasized. It has been shown that existing techniques can effectively resolve this issue considering multi-reflection propagation process forward model of inverse problem. But accuracy method still depends on separation...

In synthetic aperture interferometric radiometers applied in near-field passive millimeter-wave (PMMW) imaging, array configuration design is a crucial issue. practical applications, it difficult to balance the complexity of system hardware and imaging performance. Conventionally, minimum redundancy can achieve highest spatial resolution with given number antenna elements, but there are no redundant baselines PMMW imaging. this letter, we propose novel approach by grouping antennas. First,...

High-resolution microwave and millimeter-wave (MMW) detection recognition are often plagued with artifacts when facing complex objects concave structures due to the ignorance of high-order scattering propagation. Previous works have demonstrated effectiveness accurate near-field reconstruction by considering multiple reflections in planar dihedral structures. In this letter, we extend proposed imaging model three-dimensional (3-D) scenario. Based on shooting bouncing ray (SBR) concept, first...

Stepped frequency continuous wave (SFCW) radar achieves wide bandwidth by synthesizing series of monochromatic pulses in a consecutive manner. Uniform sampling is often performed with constant step, which turn limits the maximum unambiguous range achievable to reliably distinguish targets. Thus, small step must be selected when clutters exist at long distances even though target interests located much closer distances. This costly since large number frequencies synthesized, leads slow...

High temperature has a serious impact on the reliability and optical properties of high-power light-emitting diodes. It is great significance to obtain transient thermal distribution peak LED devices during operation for component testing, design, structure optimization. Thermal microscopic imaging based visible light thermoreflectance not only high temporal-spatial resolution, but also resolution. Therefore, this technology can be used in measurement precision semiconductor devices. In...

This paper presents a real-time calibration method for the visibility function of millimeter wave passive imaging, which can effectively correct multiplicative and additive errors in real time. In this method, phase shifter is used to adjust local oscillator periodically, functions corresponding different phases are established into equations, then estimated by least square method. After that, algorithm simulated MATLAB, verified 256 channel imaging (PMMW) system prototype developed Beihang...

The shrinking in feature size and the increasing operation frequency of integrated devices make temperature characterization thermal management a crucial aspect circuit performance design. To address these challenges, accurate information distribution or properties at submicron scale is required. There are diverse methods to measure devices. Infrared imaging common method. However, its spatial resolution limited several micrometers due diffraction effect. And temporal 2 ms. As new emerging...

Traditional linear stepped frequency continuous wave (SFCW) radar synthesizes a series of coherent pulses to get wide bandwidth, which are distributed at many points with equal intervals Δf. In some fast applications, guarantee high sweep rate, the total number is limited. Thus unambiguous range inverse proportional usually small. order reduce number, this paper proposes an optimized non-uniform distribution and introduces weighting method suppress sidelobe levels. Experimental results...

With the accumulation of high-precision star sensor models year by year, testers have put forward higher requirements for low degree automation ground test system, high maintenance costs, and difficulty in centralized management. In this context, it is very important to develop a simple easy-to-use automated system sensors. This project uses standard Ethernet interface custom communication protocol study an improve efficiency quality. Through python+Flask framework, React technology web...

Thermoreflectance imaging technique is a noncontact measurement technology that has attracted much attention in the field of thermal characteristics semiconductor devices. This often used for steady-state temperature and transient devices, with advantages high spatial resolution, time resolution. However, during device, expansion control table sample caused by rise makes optical image appear defocused. In order to ensure collected CCD not distorted, it necessary design an alignment system...

Noises from the measurement sensors are inevitable in radar cross Section testing due to thermal agitation of electrons imperfect conductors. Existing methods represented by wavelet threshold usually regard measured data as a stationary stochastic signal, ignoring inherent influence target under test, which inevitably removes signal’s component when noise increases. This paper proposes novel perspective on 2-D denoising, considering target’s scattering characteristics (ISC). In proposed...