• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.12
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• pp.969-975
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• 2018

The main function of the tracking radar is to automatically track the target. The amplitude-comparison monopulse radar utilizes a monopulse radar to estimate the angular components of a target. In this paper, the operating performance of the amplitude-comparison monopulse radar is quantitatively analyzed via the MSEs, with considerations on additive noise. The performance of the amplitude comparison monopulse radar can be predicted by comparing it with an approximated estimate.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.6
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• pp.602-609
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• 2021

Aircraft radar has special function which is ranging from aircraft to ground of antenna boresight. Because ranging information is used to calibrate altitude of aircraft or to drop a conventional bomb, the measuring have to be precise and robust. Therefore, we propose a simple and efficient method using monopulse radar for ground ranging. Proposed method calculates balancing weight according to linearity of monopulse ratio and mixes two ranging measurements in proportional to the weight. By exploiting balancing weight, radar is able to react to various environment as monopulse ratio contains characteristics of clutter environment. As a result, robust ranging information can be achieved. We use DEM(Digital Elevation Model) in order to simulate heterogeneous environment. In experimental result, it is shown that proposed method shows better accuracy and precision in any environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.7
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• pp.576-579
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• 2017

Due to the existence of flash lobe caused by the radome structure, a radar return in general contains clutter component added to target echo. Unlike jammer, clutter is apt to simultaneously coexist with target echo, which hinders a monopulse radar from estimating the angle difference between target echo direction and radar steering direction. In this paper, we propose a clutter estimation algorithm applicable to generalized sidelobe canceller(GSC) based monopulse radar. We show that clutter estimation can be achieved via iterative process of the orthogonal projections. Through simulations, the proposed GSC-based system combined with the clutter estimation can outperform the conventional monopulse system in terms of target angle estimation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.229-236
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• 2017

In general, an error budget of monopulse radar is proposed by manufacturer who assuming that all of external enviromental error resources such as multipath, glint, dynamic lag variation are removed. So until now, a measurement uncertainty of monopulse radar can be discussed including external enviromental error resources. In this paper, it is described that which kinds of error resource can effect on monopulse radar measurement uncertainty for different target property. To prove it experimentally, at first a simulation result is described assuming that all of external enviromental error resources are removed. It only includes receiver thermal noise. And then, monopulse radar measurement uncertainty estimation results tracking on calibration target which is fixed on specific position, calibration sphere which is moving slowly, weapon systems firing test which is moving fast are described quantitativly. All of these targets have different dynamic property.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.583-590
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• 2018

Cross eye technique was proposed as an angle deception jamming technique against monopulse radars. Tracking radars use monopulse or conical scan methods for angle estimation of a target. Thus, if we verify deception performance of cross eye technique against a conical scan radar, efficient jamming systems can be developed to disturb both monopulse radars and conical scan radars. In this paper, we propose a mathematical model for a conical scan radar and a cross eye system. Using the proposed model, angular deception performance of the cross eye technique against conical scan radar is analyzed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.1
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• pp.19-25
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• 2013

In this paper, we proposed an enhanced monopulse MIMO radar system for the tactical scenario where the ground receivers are connected wireless backhaul and closely spaced. By applying the ${\alpha}{\beta}$ filter to the conventional monopulse MIMO radar, we show that the localization performance can be improved significantly. We also propose an efficient localization algorithm for a system with lower rate feedback. Using numerical simulations, we demonstrate that the proposed scheme can improve the localization performance while reducing the feedback over conventional scheme.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.528-536
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• 2010

A monopulse feeder gives the most important impact upon the radiation pattern characteristics of a multi-function radar or a tracking radar which uses the space feed. It is described that the triple-mode type monopulse feeder which possesses the optimum aperture illumination for three monopulse channels is designed and measured in this paper. The measured results show that the designed feeder has not only the characteristics of the optimum aperture illimination in each channel and also very low return loss over the 10 % of fractional bandwidth at X-band. This means that the feeder provides the antenna system with low sidelobe level and high monopulse slope characteristics.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.3
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• pp.109-114
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• 2024

The effect of inter-channel coupling in multi-channel monopulse receiver is expected to increase by miniaturization trend of receiver. Therefore, in this paper, calibration method is proposed to compensation for inter-channel coupling in receiver of monopulse radar. And it can prevent distortion of angle information of target. Hardware configuration that consists of switch, directional coupler, matched load, ADC(Analog to Digital Converter), signal source of calibration is proposed to calibration. Total nine scattering parameters are obtained by controlling the switch and signal source of calibration. After that, method for restoring the undistorted signal is proposed using the mathematical relationship between the monopulse signal output from the antenna and the monopulse signal passing through the multi-channel receiver in the presence of inter-channel coupling.

• Korean Journal of Remote Sensing
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• v.36 no.3
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• pp.441-448
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• 2020

GMTI (Ground Moving Target Indication) radar system can detect ground moving targets and can provide position and velocity information of each target. However, the azimuth position of target has some offset because of the hardware errors such as mechanical tolerances. In this case, an error occurs no matter how accurate the monopulse ratio is. In this paper, target position correction method in azimuth direction has been proposed. The received sum and difference signals of monopulse GMTI system are post-processed to correct the target azimuth angle error. This method is simple and adaptive for nonhomogeneous area because it can be implemented by using only software without any hardware modification or addition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.96-103
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• 2003

A cavity-backed microstrip patch antenna for a monopulse radar system is designed and fabricated. Also, this antenna is shown to be suitable for the system by analyzing the measured results. Since the azimuthal beamwidth required by this system is quite broad compared to that of a usual microstrip antenna, the width of a microstrip patch is reduced considerably. The decrease of an antenna bandwidth due to the reduced patch width is compensated by increasing the effective substrate thickness. A detection range and a detection probability is calculated from the measured gain at a given angle, and this result shows that the fabricated antenna can be applied well to this monopulse radar system.