• 전기전자학회논문지
• /
• 제23권2호
• /
• pp.395-402
• /
• 2019

In this paper, we implemented an Ultra-Wideband radar system using Stripmap Synthetic Apertrure Radar algorithm to recognize objects inside a box. Different window functions such as Hanning, Hamming, Kaiser, and Taylor functions to improve image recognition performance are applied and implemented to radar system. The Ultra-Wideband radar system with 3.1~4.8 GHz broadband and UWB antenna were implemented to recognize the conductor plate located inside 1m3 box. To obtain the image, we use the propagation data in the time domain according to the 1m movement distance and use the Range Doppler algorithm. The effect of different window functions to improve the recognition performance of the image are analyzed. From the compared results, we confirmed that the Kaiser window function can obtain a relatively good image.

• 전기전자학회논문지
• /
• 제25권1호
• /
• pp.76-82
• /
• 2021

In this paper, the compressed sensing basic pursuit denoise algorithm adopted to synthetic aperture radar imaging is investigated to improve the object recognition. From the incomplete data sets for image processing, the compressed sensing algorithm had been integrated to recover the data before the conventional back- projection algorithm was involved to obtain the synthetic aperture radar images. This method can lead to the reduction of measurement events while scanning the objects. An ultra-wideband radar scheme using a stripmap synthetic aperture radar algorithm was utilized to detect objects hidden behind the box. The Ultra-Wideband radar system with 3.1~4.8 GHz broadband and UWB antenna were implemented to transmit and receive signal data of two conductive cylinders located inside the paper box. The results confirmed that the images can be reconstructed by using a 30% randomly selected dataset without noticeable distortion compared to the images generated by full data using the conventional back-projection algorithm.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제16권6호
• /
• pp.754-759
• /
• 2016

A transformer feedback low-noise amplifier (LNA) is implemented in a standard $0.18{\mu}m$ CMOS process, which exploits drain-to-gate transformer feedback technique for wideband input matching and operates across entire 3~5 GHz ultra-wideband (UWB). The proposed LNA achieves power gain above 9.5 dB, input return loss less than 15.0 dB, and noise figure below 4.8 dB, while consuming 8.1 mW from a 1.8-V supply. To the authors' knowledge, drain-to-gate transformer feedback for wideband input matching cascode LNA is the first adopted technique for UWB application.

• 한국전자파학회논문지
• /
• 제30권3호
• /
• pp.236-242
• /
• 2019

UWB(Ultra-WideBand)는 수 GHz 이상 광대역의 매우 짧은 신호를 이용하여 고속의 송수신이 가능한 기술로서, 최근 레이다 분야에 응용되고 있다. IR(Impulse Radio)-UWB 레이다의 경우, 높은 분해능으로 모션 인식 분야에도 적용되고 있다. 따라서, 본 논문에서는 IR-UWB 레이다를 이용한 모션 인식에 관한 연구를 진행하였다. 모션에 대한 데이터를 획득하기 위해 개발 환경을 구축하고, 성능 향상을 위한 신호처리 알고리즘을 구현하였다. 그리고 신호처리 결과를 바탕으로 모션의 특징 추출과 학습을 통해 성능을 검증하였다.

• 한국정보통신학회논문지
• /
• 제23권10호
• /
• pp.1290-1297
• /
• 2019

본 논문에서는 ultra-wideband(UWB) 시스템에서 합성곱 신경망(CNN)을 이용한 거리 추정 기법을 제안한다. 제안하는 기법은 UWB 신호를 이용하여 송신기와 수신기 사이의 거리를 추정하기 위하여 수신신호의 크기 샘플로 이루어진 1차원 벡터를 2차원 행렬로 재구성하며, 이 2차원 행렬로부터 합성곱 신경망 회귀를 이용하여 거리를 추정한다. IEEE 802.15.4a 표준의 UWB 실내 가시선 채널모델을 이용하여 수신신호를 생성하여 학습데이터를 만들며 합성곱 신경망 모델을 학습시킨다. 또한 실제 필드 시험을 통해 실내환경에서의 실험 데이터를 이용하여 거리추정 성능을 확인한다. 제안하는 기법은 기존의 문턱값 기반의 거리 추정 기법과의 성능비교도 수행하는데, 결과에 따르면 10m 거리에서 제안기법은 0.6m의 제곱근 평균 자승 에러를 보이는데 기존기법은 1.6m로 훨씬 큰 에러를 보인다.

• ETRI Journal
• /
• 제35권3호
• /
• pp.397-405
• /
• 2013

In this paper, two sets of spectrally efficient ultra-wideband (UWB) pulses using zinc and frequency-domain Walsh basis functions are proposed. These signals comply with the Federal Communications Commission (FCC) regulations for UWB indoor communications within the stipulated bandwidth of 3.1 GHz to 10.6 GHz. They also demonstrate high energy spectral efficiency by conforming more closely to the FCC mask than other UWB signals described in the literature. The performance of these pulses under various modulation techniques is discussed in this paper, and the proposed pulses are compared with Gaussian monocycles in terms of spectral efficiency, autocorrelation, crosscorrelation, and bit error rate performance.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
• /
• pp.221-224
• /
• 2005

In this paper, We have designed, fabricated and measured a stacked planar antenna for Ultra-Wideband communication. Radiation parts of the antenna have exponential curve and fed by strip feeding network. We have used the HFSS of Ansoft to simulate the antenna. It was designed to work on a substrate Teflon of thickness 1.575mm and relative permittivity 3.2. The proposed antenna covered the entire UWB band( 3.1GHz $\sim$ 10.6GHz ) for S11$\leq$l0dB. Also the proposed antenna show a good characteristics, linear phase, omni -directional pattern lot UWB applications. Besides the measured results have a reasonable agreement with the simulated results.

• ETRI Journal
• /
• 제36권2호
• /
• pp.309-312
• /
• 2014

A novel compact pattern diversity slot antenna for ultra-wideband (UWB) and Bluetooth applications is presented. This antenna consists of two modified coplanar waveguides that feed staircase-shaped radiating elements, wherein two different fork-like stubs are placed at the $45{\circ}$ axis. The measured results show that this proposed antenna operates from 2.3 GHz to 12.5 GHz, covering Bluetooth, WLAN, WiMAX, and UWB. The performance of radiation patterns and the corresponding envelope correlation coefficient prove this antenna is suitable for MIMO/diversity systems. Also, the antenna's compact size makes it a good candidate for portable devices.

• 전기학회논문지P
• /
• 제58권1호
• /
• pp.33-37
• /
• 2009

In this paper, a printed small Ultra-Wideband (UWB) antenna with directive radiation characteristics based on combination of electric-magnetic radiators is presented. The combinations of the electric and magnetic type antennas result in the directive radiation patterns for all observed UWB frequency band. Simple combination of dipole antenna and loop antenna is also presented to show that proper configuration of electric radiator and magnetic radiator can produces directive radiation characteristics. The target frequency is from 3.1 GHz to 10.6 GHz with size of $15\;mm{\times}31\;mm$. A proto-type of the combined antenna is simulated, fabricated and measured. Simulation and experimental results of input impedance and gain characteristics of the proposed antenna are presented. There are good agreements between the simulated and measured VSWR curves. Also, the results show the directive radiation characteristics with small antenna form factor over the target frequency range.

• 전기학회논문지P
• /
• 제59권1호
• /
• pp.47-52
• /
• 2010

The low power of ultra-wideband (UWB) signal makes the acquisition of UWB signal be a more challenging task. In this paper, we propose the method of high order template signal technique that reduces the synchronization time. Experimental results are presented to show the improvements of performance in the mean acquisition time (MAT) and the probability of detection. The performance compared with the serial search, the truly random search and the random permutation search. It is shown that over typical UWB multipath channels, a random permutation search scheme may yield lower MAT than serial search.