• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.5
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• pp.514-520
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• 2015

Sidelobe canceller(SLC) requires main beam pattern(SUM beam) and auxiliary beam patterns for rejection of sidelobe noise jammer. For best performance of sidelobe noise jamming cancellation of adaptive SLC, gain dominant region of each auxiliary beam pattern shall not be overlapped one another in elevation/azimuth regions of sidelobe of main beam, and beam patterns of auxiliary channels should have low gains in regions of mainlobe of main beam. In the monopulse radar, the difference beam patterns for monopulse processing have these properties. This paper proposes the method using data from the difference channel for monopulse processing as data from auxiliary channel for sidelobe cancellation. For the proposed SLC, the results of simulation and performance analysis was presented. If the proposed method is used in the monopulse radar, SLC can be constructed by using basic SUM and difference channels without extra channel composition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.7
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• pp.500-507
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• 2018

A three-channel radio frequency (RF) monopulse receiver using a data signal with a maximum transmission rate of 274 Mbps was designed. A monopulse receiver using a broadband communication signal was designed to operate in the Ku band, and it consists of a down-conversion module and a signal-processing module. To satisfy the performance of the proposed RF monopulse receiver, a signal-processing function less than the reception sensitivity for each transmission rate according to the adaptive transmission rate is required. To minimize signal reception and mutual frequency interference of various bandwidths, two RF filters were applied. To verify the satisfaction of system requirements, an AWR Corp. simulation tool was used.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.582-589
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• 2016

Multi-mode monopulse system is widely used for satellite terminal like UAV because of high tracking accuracy and low size/weight profile. In order to calculate tracking error, Multi-mode monopulse system utilizes high-order mode signal, and it should have enough C/N(carrier to noise) level therefore tracking system needs narrow band filtering of received satellite beacon signal as much as possible. However, UAV suffers for beacon frequency drift derived from Doppler effect due to satellite figure 8 movement and UAV maneuvering. Therefore wideband signal processing needs to be considered in advance for exact doppler compensation and consequent time delay. In this paper, we propose the multi-stage Digital Signal processing system for beacon signal, which could minimize the signal delay under high Doppler and low C/N condition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.12
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• pp.999-1002
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• 2017

For a target echo containing interference, it is very difficult to improve the performance of a monopulse radar with spatial domain processing, because the statistical property of interference cannot be exclusively obtained. This paper proposes a monopulse system that has a generalized sidelobe canceller(GSC) filter-based time domain processor as a preprocessor prior to conventional monopulse spatial processing. We analytically show the procedure of time-space signal processing running in the system, and assess its performance through simulation. In particular, the performance dependence on the number of taps in the main channel filter and the estimation error in Doppler frequency are assessed by comparison with those of existing systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.10
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• pp.1212-1215
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• 2012

This study describes the accuracy improvement of the estimated angle using phase averaging in phase-comparison monopulse algorithm. In addition, to compensate the time-delay due to the phase averaging, we propose the time-delay compensation algorithm which uses the derivative of the estimated angle. These derivative is calculated by the curve fitting method. Using the real radar interferometer, we have verified that the phase averaging and time-delay compensation algorithms are effective in real-time signal processing application.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.410-413
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• 2012

This study describes the performance comparison to solve angle ambiguity needed to angle of arrival estimation in 2D radiometer. There are three algorithms to solve its ambiguity such as phase-comparison monopulse method, digital beam-forming method and least square error of the phase difference in 2D radar interferometer. To estimate two direction angles, phase-comparison monopulse method is sequentially applied to azimuth and elevation direction. To analyze the performance of these methods, probability of solving angle ambiguity and execution time have been chosen as performance indexes. Through the Monte Carlo simulation, we have verified that phase-comparison monopulse method is most effective in real-time signal processing application.

• The Journal of the Acoustical Society of Korea
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• v.15 no.1
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• pp.34-39
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• 1996

Target state estimation is a fundamental problem of the sonar signal processing. In this paper, the covariance analysis techniques are applied to enhance the performance of the target state estimation of a monopulse sonar system. MOST, the artificial target signal generator based on the highlight model is used to generate signals in various target states. The performance of the developed method has been evaluated by applying it to the various S/N. The enhanced performance of the covariance analysis method presented in this paper is discussed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.2
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• pp.27-32
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• 2018

In this paper, W-band transceiver module for compact radar has been designed and fabricated. Utilizing proposed microstrip-to-waveguide transition, the error between design and implementation is reduced. The proposed transition provides less than 1 dB insertion loss per transition and reliability for fabrication. In order to apply compact radar with dual-polarized monopulse directly, W-band transmitter with 28 dBm output power is designed and developed. Also, 6 channels of receiver module with low noise figure 13.5 dB and maximum 17 dBm input P1dB is developed. Proposed W-band transceiver module is expected compact radar application for dual-polarized monopulse signal processing system.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.1
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• pp.109-117
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• 2005

Range and velocity measurement algorithm is a procedure for estimating the accurate target position by using matched filter outputs equally spaced both in range and doppler frequency domain. Especially, in measurement algorithm for multi-function radar, it is necessary to consider processing time as well as accuracy in order to track multi-targets simultaneously. In this paper, we analyze range and velocity measurement algorithm using discriminator estimation method which is a technique applied to angle measurement of monopulse radar. The applied method required constant processing time for estimation can be used in multiple target tacking. But, it is necessary to consider measurement accuracy because of using minimum channel outputs for estimation. In the simulation, we show that the applied method is superior to the traditional gravity center measurement algorithm with respect to the accuracy performance and also analyze the characteristics of the proposed technique by calculating RMS error level as the processing parameters such as pulse width , channel step, etc. change.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.99-107
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• 2014

Abruptly occurred obstacles on highway threaten driving safety. Radar draws the attention to the collision avoidance system because it can be fully operational in all weather, and day and night condition. This paper presents the design, implementation and performance test results of pulsed Doppler radar system for detection and warning of road obstacles. The system is designed to consider highway environment and detection capability about various fixed and moving obstacles. The system consists of 4 subsystems, which include antenna unit, transmitter and receiver unit, radar signal & data processing unit, and controller & display unit. The core technologies include clutter map based change detection for fixed obstacles detection, Doppler estimation for velocity detection of moving targets, and azimuth angle estimation method using monopulse for lane estimation and tracking. The design performance of the developed radar system is verified through experiments using a fixed reference target and moving vehicles in test highway.