A5066782018- Radar Systems and Signal Processing
- Antenna Design and Optimization
- Advanced SAR Imaging Techniques
- Electromagnetic Compatibility and Measurements
- Microwave Engineering and Waveguides
- Antenna Design and Analysis
- Engineering Applied Research
- Internet of Things and Social Network Interactions
- Radio Wave Propagation Studies
- Martial Arts: Techniques, Psychology, and Education
- Industrial Vision Systems and Defect Detection
- Rocket and propulsion systems research
- Image and Object Detection Techniques
- Optical Systems and Laser Technology
- Infrared Target Detection Methodologies
- Traditional Chinese Medicine Studies
- Advanced Frequency and Time Standards
- Electromagnetic Simulation and Numerical Methods
- Fault Detection and Control Systems
- GaN-based semiconductor devices and materials
- Radio Frequency Integrated Circuit Design
- Superconducting and THz Device Technology
- Advancements in Semiconductor Devices and Circuit Design
- Electromagnetic Compatibility and Noise Suppression
- Photonic and Optical Devices
Agency for Defense Development
2020
GS Caltex (South Korea)
2019
Defence Science and Technology Agency
2019
Medium pulse repetition frequency (MPRF) waveforms are used in common airborne radar because of their advantages. However, one the disadvantages MPRF is decrement detectable ranges by sidelobe clutter at low-altitude platforms. To overcome this disadvantage and to increase platforms, study proposes a reduction method. Airborne has sum difference antenna channels, processed using sigma-delta spatio-temporal adaptive processing sidelobe-clutter surroundings In terms performance effectiveness...
To prevent the detection performance of radar systems from being degraded by interference signals appearing in side-lobe antenna, an additional blanking(SLB) antenna is often added and operated alongside main antenna. In this paper, SLB composed array elements within discussed. Using structural features digital active phased implies that no physically added. Optical channels are also employed to simultaneously form multiple beams for antennas. A structure cover all side-lobes pattern was...
This study analyzes the performances of junior representatives in Group B 12-14 years during 11th Asian Junior Wushu Championships 1st International Competition Taolu. In sideways leaning balance balance, it was found that minimizing distance between base support supporting leg and center mass upper body is crucial for maintaining static a stable position. During preparatory phase staff form Gunshu, important to swiftly control movements while bow stance. butterfly stance, heel back foot...
본 논문에서는 항공기 레이더에 적용 가능한 능동배열 안테나의 배열오차 분석 및 보정에 대한 시험 결과를 기술하였다. 복사소자, TR 모듈, 급전기 등으로 구성되는 배열소자 간의 크기 위상오차는 안테나 부엽 준위에 영향을 미치며, 이는 개구면 weighting에 따른 이상적인 부엽레벨, 개수, 효율 등에 의해 그 민감도가 달라진다. 시스템에서 요구되는 부엽준위를 만족시키기 위해서는 배열소자의 오차 보정이 반드시 이루어져야 한다. 방법은 오차요소에 따라 다르게 적용되어야 하며, 형태, 목표 고려되는 수준의 차이가 달리 요소와 영향에 대해 분석하였으며, 보정 방안을 제시하였다. 또한, 근접 전계 시험을 통해 확인하였다. Array error analysis and correction of active array antenna are described in this paper. elements composed radiator TR(Transmit & Recive) module...
Recent advances in hardware have resulted the introduction of an integrated transmit/receive single chip that can not only transmit and receive RF(Radio Frequency) signals, but also perform analog to digital data conversion. This makes it easier develop element-level active phased array(DAPA) antennas. Owing that, there is increasing demand for radar applications, including multi-function radar. The transmitting(Tx) near-field measurement configuration applied verify performance traditional...
Herein, we describe the receiving (Rx) near-field measurement of digital active phased array antennas applicable to multifunction radars. Because structural differences with analog antennas, it is difficult apply conventional Rx test configuration. Therefore, have proposed a configuration suitable for arrays. In simulation, results are presented beam pattern distorted by leakage signal generated in near field and corrected these signal. After which, based on results, measured data reviewed....
We demonstrated a successful fabrication of 4 ” Gallium Nitride (GaN)/Diamond High Electron Mobility Transistors (HEMTs) incorporated with Inner Slot Via Hole process. made in manufacturing technology 4” GaN/Diamond HEMT wafers compound semiconductor foundry since reported [1]. Wafer thickness uniformity and wafer flatness starting have improved greatly, which contributed to processing yield. By optimizing Laser drilling techniques, we successfully through-substrate-via process, is last...
In this paper, we propose a beam operation policy and waveform design method to efficiently detect nose-aspect targets(long-distance threats) using an active electronically scanned array(AESA) radar.The target information be obtained through the radar is identified by considering characteristics of long-range threats/targets, suitable for designed.This paper presents considerations methods efficient acquisition information, which extracted operation, associated performance constraints.To...
In a multi-function radar, the adaptive beamforming algorithm is one of several methods that can be applied to restore degraded SINR(Signal-to-Interference Noise Ratio) its original level. This employed for regular operation radars in jamming situations, when unwanted high-power signals are received. this paper, we introduce few algorithms digital radar situations. Furthermore, compare and analyze performance terms SINR sidelobe level characteristics by applying each specific planar array...
The waveform operation and signal processing design in sea surveillance radar, which radiates radar pulse signals while rotating at fixed revolutions per minute (RPM), for detecting targets is shown. described this paper has multiple receiving channels to concurrently detect both low high speed such as ships aircrafts. In repetition frequency (PRF) operations, medium PRF waveforms are applied, respectively. This describes an incomplete set that capable of resolving range ambiguity, but...
본 논문에서는 94 GHz Gunn 고정발진기를 설계 및 제작하였고, 이를 이용하여 발진기에 사용된 다이오드의 최대 전력을 조사하였다. 고정발진기는 InP 다이오드가 사용되었고, WR-10 도파관 구조로 제작되었다. 제작된 발진기는 발진주파수 95 GHz에서 12.64 dBm의 출력 전력과 1 MHz 오프셋 주파수에서 -92.7 dBc/Hz의 위상잡음 성능을 보였다. 조사하기 위해서 발진기 구조를 턱이 있는 수정하였다. 그리고 이 턱의 높이를 변화시켜, 발진기가 몇 가지의 다른 부하 임피던스를 갖도록 하였다. 임피던스에 대한 결과로써, 포스트 면에서의 실수부 <TEX>$G_L$</TEX>에 발진 신호 <TEX>$V^2$</TEX>의 그래프를 얻었다. <TEX>$G_L-V^2$</TEX>의 이용하여, 바이어스 포스트의 손실이 포함된 전력 16.8 dBm을 short된 다이오드와 제로 상태의 다이오드를 손실을 계산하였다. 보상한 다이오드만의 전력은 18.55 dBm이다. 이는...
This study presents the results of acquisitions Doppler beam sharpening(DBS) images, obtained through flight trials airborne active electronically scanned array(AESA) radar. To use AESA radar for DBS image acquisition, we designed methods operation and formation considering peculiarities Selection pulse repetition frequency(PRF) waveforms to achieve required azimuth resolution images are described, steps implementation our method presented explained. Under condition mounting on ramp door...
Leakage signals, inevitably generated during near-field measurement of a digital radar, affect the measured data samples. Although each leakage signal occurs at very low level, signals accumulate and have significant effect when converts into far-field beam pattern. In this study, we verified method that effectively eliminates through back projection from data. simulation, difference between characteristics noise was examined, simulated with mathematical modeling. Next, analyzed on antenna...
It is difficult to detect a stationary or slow-moving periscope having small radar cross-section in maritime environment. This paper presents detection method using the Hough transform by selecting parameters based on an active electronically scanned array ship-borne X-band multi-function radar. The was evaluated through modeling and simulation.
Linear frequency modulation(LFM) waveforms in pulsed radars are extensively used owing to their excellent Doppler tolerance and low side-lobe level characteristics after pulse compressions. On the contrary, it is difficult determine target velocity from single-pulse LFM because of tolerance. If possible detect range targets with only transmission reception, multi-function can gain advantages terms resource management. In this paper, we propose a method estimating using waveforms. The...