Active Phased Array Radar Systems Research Articles

Design and Simulation Analysis of Antenna Structure for Active Phased Array Radar

Abstract This article adopts a modular design concept to design an active phased array radar antenna system structure and elaborates on its structural layout design and thermal design content. A finite element model of the antenna structure framework was established, and the rationality of its structural and thermal design was verified through static and thermal simulation analysis.

A Software-Defined Radar for Low-Altitude Slow-Moving Small Targets Detection Using Transmit Beam Control

Low-altitude slow-moving small (LSS) targets are defined as flying at altitudes less than 1000 m with speeds less than 55 m/s and a radar crossing-section (RCS) less than 2 m2. The detection performance of ground-based radar using the LSS target detection technique can be significantly deteriorated by the diversity of LSS targets, background clutter, and the occurrence of false alarms caused by multipath interference. To address the LSS target detection problem, we have devised a novel two-dimensional electronic scanning active phased array radar system that is implemented in the software-defined radar architecture and propose a transmit beam control algorithm based on the low peak-to-average ratio (PAPR). Meanwhile, we devised a flexible arbitrary radar waveform generator to adapt to complex environmental situations. Field experiment results effectively demonstrate that our radar can be used to detect LSS targets. Moreover, an ablation experiment was conducted to verify the role played by transmit beam control and adaptive waveform optimization and generation in improving the system performance.

A Study on Calibration of Transmitter and Receiver Channels Using Coupling Lines in an Active Phased Array Radar System

본 논문에서는 능동위상배열 레이더에서 커플링 라인을 이용하여 송수신 채널을 보정하는 방법을 제안한다. 무반향실에서 각 채널 별 특성을 측정하여 보정하는 것이 이상적이나, 야전에서 운용되는 레이더의 경우 채널보정을 위한 추가적인 시스템을 구비하여야 한다. 본 논문에서 제안한 방법은 레이더를 야전에서 사용할 때 적용할 수 있는 장점이 있다. 능동위상배열 레이더의 송수신 채널을 각각 제어하여 안테나에서 방사된 신호가 커플링 라인으로 유기되는 신호를 수신하여 채널 간 크기 및 위상차를 보정하였다. 무반향실에서 측정한 송수신 채널의 보정값을 적용한 레이더의 빔 패턴과 제안된 방법을 이용하여 측정한 보정값을 적용한 레이다의 빔패턴을 비교하였고, 부엽 준위는 유사하였으나 반전력 빔폭이 약 2.7% 오차를 가졌다.

X-대역 능동 위상 배열 레이더시스템용 저전력 GaAs MMIC 다기능 칩

본 논문에서는 X-대역 능동 위상 배열 레이더 시스템에 사용되는 MMIC 다기능 칩을 0.5 <TEX>${\mu}m$</TEX> p-HEMT 상용 공정을 이용하여 저전력 특성을 가지도록 개발하였다. 다기능 칩은 6-비트 디지털 위상 천이 기능, 6-비트 디지털 감쇠 기능, 송/수신 모드 선택 기능, 신호 증폭 기능 등의 다양한 기능을 제공한다. <TEX>$16mm^2(4mm{\times}4mm)$</TEX> 칩 크기의 소형으로 제작된 MMIC 다기능 칩은 7~11 GHz에서 10 dB의 송/수신 이득 특성과 14 dBm의 P1dB 특성을 가지며, DC 소모 전력이 0.6 W로 매우 낮은 저전력 특성을 보였다. 그리고 6-비트, 64 상태에 대해 위상 천이 특성과 감쇠 특성의 측정 결과, 동작 주파수에서 <TEX>$3^{\circ}$</TEX>의 RMS(Root Mean Square) 위상 오차와 0.6 dB의 RMS 감쇠 오차를 보였다. An MMIC multi-function chip with a low DC power consumption for an X-band active phased array radar system has been designed and fabricated using a 0.5 <TEX>${\mu}m$</TEX> GaAs p-HEMT commercial process. The multi-function chip provides several functions: 6-bit phase shifting, 6-bit attenuation, transmit/receive switching, and signal amplification. The fabricated multi-function chip with a compact size of <TEX>$16mm^2(4mm{\times}4mm)$</TEX> exhibits a gain of 10 dB and a P1dB of 14 dBm from 7 GHz to 11 GHz with a DC low power consumption of only 0.6 W. The RMS(Root Mean Square) errors for the 64 states of the 6-bit phase shift and attenuation were measured to <TEX>$3^{\circ}$</TEX> and 0.6 dB, respectively over the frequency.

Design and Implementation of the Digital Transceiver Unit for VHF Active Phased Array Radar System

Design and Implementation of the Digital Transceiver Unit for VHF Active Phased Array Radar System

실시간으로 적응빔형성 및 신호처리를 수행하는 평면능동위상배열 레이더 시스템 개발

Interference and jamming are becoming increasing concern to a radar system nowdays. AESA(Active Electronically Steered Array) antennas and adaptive beamforming(ABF), in which antenna beam patterns can be modified to reject the interference, offer a potential solution to overcome the problems encountered. In this paper, we`ve developed a planar active phased array radar system, in which ABF, target detection and tracking algorithm operate in real-time. For the high output power and the low noise figure of the antenna, we`ve designed the S-band TRMs based on GaN HEMT. For real-time processing, we`ve used wavelenth division multiplexing technique on fiber optic communication which enables rapid data communication between the antenna and the signal processor. Also, we`ve implemented the HW and SW architecture of Real-time Signal Processor(RSP) for adaptive beamforming that uses SMI(Sample Matrix Inversion) technique based on MVDR(Minimum Variance Distortionless Response). The performance of this radar system has been verified by near-field and far-field tests.

위상 배열레이더의 다채널 수신 데이터 전송 기법

The trend for the development of radar is the active phased-array radar system. The trade-off between the processing speed and the number of the signal process board for the real time signal processing has to be optimized particularly in multichannel radar system. This paper introduces a transmission technique in order to transmit a large amount of received data from an Antenna Part to Signal Process Part. As a result, the number of the S/L board(COTS board) is reduced to one half, and the margin of the data transmission rate is about 2 times higher than the original method.

X-대역 능동 위상 배열 레이더 시스템용 디지털 직병렬 변환기를 포함한 GaAs MMIC 다기능 칩

An MMIC multi-function chip for an X-band active phased array radar system has been designed and fabricated using a 0.5 GaAs p-HEMT commercial process. A digital serial-to-parallel converter is included in this chip in order to reduce the number of the control interface. The multi-function chip provides several functions: 6-bit phase shifting, 6-bit attenuation, transmit/receive switching, and signal amplification. The fabricated multi-function chip with a relative compact size of 24 (6 mm4 mm) exhibits a transmit/receive gain of 24/15 dB and a P1dB of 21 dBm from 8.5 GHz to 10.5 GHz. The RMS errors for the 64 states of the 6-bit phase shift and attenuation were measured to and 0.3 dB, respectively over the frequency.

Evaluation of Weather Radar with Pulse Compression: Performance of a Fuzzy Logic Tornado Detection Algorithm

Abstract Trends in current weather research involve active phased-array radar systems that have several advantages over conventional radars with klystron or magnetron transmitters. However, phased-array radars generally do not have the same peak transmit power capability as conventional systems so they must transmit longer pulses to maintain an equivalent average power on target. Increasing transmits pulse duration increases range gate size but the use of pulse compression offers a means of recovering the otherwise lost resolution. To evaluate pulse compression for use in future weather radar systems, modifications to a weather radar simulator have been made to incorporate phase-coding into its functionality. Data derived from Barker-coded pulses with matched and mismatched filters were compared with data obtained from uncoded pulses to evaluate the pulse compression performance. Additionally, pulse compression was simulated using data collected from an experimental radar to validate the simulated results. The data derived from both experimental and simulated methods were then applied to a fuzzy logic tornado detection algorithm to examine the effects of the pulse compression process. It was found that the fuzzy logic process was sufficiently robust to maintain high levels of detection accuracy with low false alarm rates even though biases were observed in the pulse-compressed data.

Optimal number of array faces for active phased array radars

The number of array faces is an important factor in determining antenna and radar system performance, cost, and manufacturing complexity. The subject of determining the optimum number of antenna faces has been addressed previously by several authors (Knittel,1965) using various figures of merit. For active phased array radars performing tracking and discrimination functions, the important figure of merit for antenna performance is power-aperture-gain (PAG) product. We determine the optimal number of faces by choosing PAG product as the figure of merit for the same tracking and discrimination performance at maximum scan angles. Given equal antenna performance at maximum scan angles in the coverage area, cost is the primary basis for comparison in the selection of the number of faces for a modern active phased array radar system.