• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1984-1986
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• 2003

본 논문은 UWB(Ultra WideBand) 기술에 기반한 지반탐사레이더(Ground Penetrating Radar, GPR)용으로 개발된 광대역 안테나의 특성에 관해 나타낸다. UWB 기술의 핵심은 주기가 수 나노초 이하의 짧은 임펄스를 이용하는 것으로 지반탐사레이더는 이 임펄스 기술을 이용함으로서 탐사 능력과 해상도를 높일 수 있다. 임펄스 전송을 위해 안테나는 넓은 대역폭, 크기, 무게, 가격 등 지반탐사레이더에 적용될 수 있는 조건을 만족해야 함으로 안테나의 설계는 이에 부합할 수 있는 다이폴 안테나를 선택하여 개발하였다. 개발된 안테나의 성능을 검증하기 위해 시뮬레이션과 실험을 실시하였고 그 결과 설계된 안테나의 대역폭이 0.5 GHz에서 2.7 GHz로 2.2 GHz(138%)의 사용대역을 나타냄으로서 UWB 기술에 기반한 지반탐사레이더용으로 유용함을 확인하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.11
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• pp.1054-1062
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• 2011

This study describes the time domain imaging algorithm which can be well applied to short-range UWB(ultra wideband) bistatic radar. In the imaging method of SAR technology, the frequency domain method is well applied to the areas which satisfy far-field condition. However in the near-field environment, the image quality is not good due to phase error. However back-projection method based on time domain is well applied to short-range imaging radar. Meanwhile because its processing time is very long, real time-processing is very difficult. To resolve this problem FFBP(Fast Factorized Back-Projection) was proposed. Using the raw data gathered on field we implemented back-projection and FFBP method. Then image quality and processing time were analyzed using these methods.

• Journal of Satellite, Information and Communications
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• v.12 no.1
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• pp.64-71
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• 2017

In this paper, Kalman filter and RRWA algorithm are used to estimate the accurate target in IR-UWB (Impulse-Radio Ultra Wideband) radar system, which enables accurate location recognition of indoors and outdoors with low cost and low power consumption. In the signal reflected by the target, unnecessary signals exist in addition to the target signal. We have tried to remove unnecessary signals and to derive accurate target signals and improve performance. The location of the targets is estimated in real time with one transmitting antenna and one receiving antenna. The Kalman filter was used to remove the background noise and the RRWA algorithm was used to remove the reflected signal. In this paper, we think that it will be useful to study the accurate distance estimation and tracking in future target estimation.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.1-10
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• 2017

In this paper we propose three existing reflection removal algorithms and one proposed algorithm to estimate accurate targets in near field using IR-UWB (Impulse-Radio Ultra Wideband) radar. The received signal includes unnecessary reflected wave signals to the target signal. A reflective cancellation algorithm was used to remove unnecessary signals and estimate only the correct target signal. The location of the targets is estimated in real time with one transmitting antenna and one receiving antenna. In order to overcome the disadvantages of the existing three reflection removal algorithms, we propose a new reflection removal algorithm and estimate the most accurate target. Also we used DSP(Digital Signal Processor) to install the external mounting of vehicles. This paper will contribute to the study of the future reflections.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.5
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• pp.319-325
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• 2011

Recently, collision avoidance systems are under development to reduce the traffic accidents and driver comfort for automotive radar. Pulse radar can detect their range and velocities of moving vehicles using range gate and FFT(Fast Fourier Transform) of the doppler frequency. We designed the real time DSP(Digital Signal Processing) based automotive UWB(Ultra Wideband) radar, and implemented DSP to detect the range and velocity within 100ms for real time system of the automotive UWB radar. We also measured the range and velocity of a moving vehicle using designed automotive UWB radar in a real road environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5C
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• pp.555-560
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• 2009

A vehicle radar has been studied to avoid the collision of vehicles. A vehicle radar using direct sequence-ultra wideband (DS-UWB) measures the distance between a vehicle and an objective with a sufficient time margin. Therefore, the receiver should estimate the distance by processing the short UWB pulse rapidly. There have been several investigations for distance measuring based on DS-UWB signals. In this paper, we propose a novel method for rapid measuring processing time. Simulation results show that the proposed method has a shorter processing time than the conventional method.

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.677-688
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• 2017

In order to solve the undetected probability of multiple targets in ultra-wideband (UWB) through-the-wall radar imaging (TWRI), a time-delay and amplitude modified back projection (BP) algorithm is proposed. The refraction point is found by Fermat's principle in the presence of a wall, and the time-delay is correctly compensated. On this basis, transmission loss of the electromagnetic wave, the absorption loss of the refraction wave, and the diffusion loss of the spherical wave are analyzed in detail. Amplitude compensation is deduced and tested on a model with a single-layer wall. The simulating results by finite difference time domain (FDTD) show that it is effective in increasing the scattering intensity of the targets behind the wall. Compensation for the diffusion loss in the spherical wave also plays a main role. Additionally, the two-layer wall model is simulated. Then, the calculating time and the imaging quality are compared between a single-layer wall model and a two-layer wall model. The results illustrate the performance of the time-delay and amplitude-modified BP algorithm with multiple targets and multiple-layer walls of UWB TWRI.

• Journal of electromagnetic engineering and science
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• v.9 no.4
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• pp.202-210
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• 2009

In this paper, we have analyzed the effect of interference between ultra-wideband(UWB) and intelligent transport systems(ITS). The maximum possible UWB emission power and minimum possible distance between UWB devices and ITS are found. In order to analyze the interference, we employ the Monte-Carlo(MC) method. We consider six situations, which are indoor office line-of-sight(LOS), indoor office non-line-of-sight(NLOS), indoor residential LOS, indoor residential NLOS, outdoor rural LOS, and outdoor rural NLOS environments. From the simulation results, it is confirmed that coexistence between UWB and ITS devices can be realized in accordance with the emission mask of 19.3 dB for indoor application or 19.3 dB for an image system. And in the outdoors, coexistence between UWB and ITS devices can be realized if the emission mask is at least 1.6 dB for vehicles' radar systems.

• Journal of Satellite, Information and Communications
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• v.11 no.4
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• pp.81-88
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• 2016

In this paper, we propose an adaptive multi-target estimation algorithm using the characteristics of signals in the IR-UWB(Impulse-Radio Ultra Wideband) radar system, which is attracting attention because it has good transparency, robustness to the indoor environment, and high precision positioning of tens of centimeters. We proposed an algorithm that estimates multiple peaks with the characteristic that the signal reflected by the target has a peak. To verify the performance of these algorithms, multiple targets were placed in front of the radar and the existing technique and the multi - target estimation algorithm were compared. The location of the targets is estimated in real time with one transmitting antenna and one receiving antenna. The number of estimates can be increased compared with the existing peak signal derivation method, and multiple targets can be derived. The conventional technique estimates only one target, which results in a mean square error of 1 while a multi - target estimation algorithm yields a result of about 0.05. The proposed method is expected to be able to apply multiple targets to the estimation and application in one IR-UWB module environment.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.101-106
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• 2005

A ground penetrating image radar (GPR) using an ultra wideband (UWB)impulse waveform is developed for non destructive detection of metallic pipelines buried under the ground. Dielectric constant of test field is measured and then a GPR system is designed for better detection up to 1 meter deep. By considering total path loss, volume of complete system, and resolution, upper and lower frequencies are chosen. First, a UWB impulse for the frequency bandwidth of the impulse is chosen with rising time less than 1 ns, and then compact planar UWB dipole antenna suitable for frequency bandwidth of a UWB impulse is designed. Also, to receive reflected signals, a digital storage oscilloscope is used. For measurement, a monostatic technique and a migration technique are used. For visualizing underground targets, simple image processing techniques of A-scan removal and B-scan average removal are applied. The prototype of the system is tested on a test field in wet clay soil and it is shown that the developed system has a good ability in detecting underground metal objects, even small targets of several centimeters.