• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.10
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• pp.900-908
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• 2016

In this paper, we have studied the tracking system with a single channel monopulse receiver that has a comparative advantage of costs, size, weight, and power consumption over the general 3-channel monopulse receivers. After the single channel monopulse system was composed of an antenna, a monopulse receiver, a servo unit, a RF signal processor unit and a power supply unit, we analyzed the basic tracking performance of the tracking error angle and the pointing loss. And we proved the tracking performance to a moving target in the outdoor environment. On the Analysis of the tracking test results, the single channel monopulse system shows a equal or higher performance over the general 3-channel monopulse system and also has advantages of the system implementation. Also, it is concluded that this study is useful to apply a single channel monopulse receiver with benefits of production price and miniaturization when the monopulse tracking systems will be developed in the future.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.705-712
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• 2018

The radiation characteristics of a phased array antenna is changed according to the beam steering angle. The monopulse tracking system calculates the prediction angle using the radiation characteristics of antenna. Therefore, the monopulse ratio curve is changed according to the beam steering angle for the monopulse tracking system using a phase array antenna, and the tracking accuracy goes down. In the case of a single-channel monopulse system, the monopulse rate curve is controlled by the configuration variables of the system. In this paper, a simplified formula was presented for adaptive control of monopulse system configuration variables on beam steering angle. The presented formula can induce a uniform monopulse ratio curve for the beam steering angle as well as the phased array antenna design parameters.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.1
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• pp.83-92
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• 2001

In this paper, the monopulse channel receiver which can be matched between channels through a wide bandwidth has been proposed. The effects of the gain and phase imbalance between channels on the slope of monopulse error signal were analyzed. Also, the matching method between channels in a wide bandwidth was proposed, by which monopulse slope could be stabilized. Using the implemented monopulse radar system the monopulse slope was measured in the anechoic chamber which include the moving horn antenna and the target signal generator. The results show that the wide band matching method is useful and applicable to various channel receivers

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.11
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• pp.1299-1308
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• 2007

In this paper, we propose the calibration method of monopulse slope to minimize the variation of angle estimate in frequency agile noncoherent monopulse system. We analyze the monopulse slope characteristics of antenna and RF receiver including the phase and gain imbalances of each receiving channel and present the calibration method to minimize the phase and gain imbalances of RF receiver channels including antenna. In addition, we present the calibration method using channel switching to minimize the gain imbalance of IF receiver channels. The measured average monopulse slope within the frequency bandwidth is -0.96, the maximum variation of angle estimate is similar to theoretical value, $0.15^{\circ}$ at ${\pm}2^{\circ}$ azimuth and $0.03^{\circ}$ at $0^{\circ}$ azimuth.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.35-43
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• 2014

In this paper, we propose a performance enhancement method of the target tracking system for communication signal using the monopulse and the ${\alpha}{\beta}$ filter to keep the connection of the communication system between the airplane and the ground. We suggest the minimum distance measurement method for tracking error angle of the monopulse signal instead of the generally used method of MR(Monopulse Ratio) curve, and the ${\alpha}{\beta}$ filter with variable gain for enhancement of the tracking accuracy and the probability of re-tracking the monopulse signal under the disconnection of link. We show the performance enhancement of the proposed method of monopulse system using the measured MR Curve results of the prototype system. And also, the comparison of simulation results between the ${\alpha}{\beta}$ filter with variable gain and the ${\alpha}{\beta}$ filter with fixed gain shows the performance enhancement of the proposed ${\alpha}{\beta}$ filter. Using the proposed methods, we expect the enhanced performance of the existing target tracking system for communication signal only by changing the algorithm without hardware changes.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.2
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• pp.272-278
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• 2017

In this paper, we consider a single-channel amplitude comparison monopulse system(SCACMS). The monopulse ratio curve(MR-C) of the SCACMS can be controlled by an amplitude difference between sum and different signal, a phase difference and the coefficient of the signal processor. We first propose the SCACMS with multiple variables, and then apply a genetic algorithm to optimize the multiple variables in terms of minimizing a root mean square error. The simulation results show that when three variables of the SCACMS are jointly optimized, the linear region of the MR-C can be extended approximately 187 % compared to that of two variables.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.176-179
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• 1987

• 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 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.