• 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.19 no.3
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• pp.363-370
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• 2016

This paper proposes a Ku-band multi-mode coupler and its monopulse tracking system, which can be applied to a unmaned aircraft vehicle(UAV) platform. In general, the carrier-to-noise(C/N) level of the beacon signal from a Ku-band commercial satellite is relatively weak compared to that of a military satellite because the Ku-band satellite has been designed for commercial services. Therefore, this paper proposes a coupler and its multi-mode monopulse tracking system satisfying the tracking accuracy under a low C/N environment and analyzes the tracking accuracy. After that, we perform a real satellite tracking test and compare the accuracy of the test with the analysis result before validating the performance of the architecture of the proposed satellite tracking system.

• 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.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.82-85
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• 1987

Electromagnetic waves from the satellite may be utilized to direct the tracking antenna toward the satellite. We design and fabricate the feed appropriate to the monopulse tracking technique which derive angle-error information on the basis of a single pulse. The feed consists of five cavity-backed turnstile elements mounted on a common ground plane. The turnstile dipole are connected to a set of five quadrature hybrids which convert the dual linear polarization into dual circular polarization. The five feed outputs are then processed in the monopulse comparator which is constructed in microstrip for compactness.

• Journal of IKEEE
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• v.26 no.1
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• pp.137-140
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• 2022

In this paper, we proposed a new W-band monopulse tracking system based on reflectarray antenna structure. The proposed reflectarray antenna monopulse tracking system consists of four feed horn antennas and a planar reflector using a microstrip reflectarray. The four feed horn antennas have a gain of 10 dBi and a half-power beam-width of 56 degrees symmetrically in the E/H plane. It was confirmed that the reflectarray antenna using one feed horn antenna has a size of 41.8 × 41.8 mm², a gain of 26.8 dBi, and a half-power beam-width of about 5.6 degrees. The reflectarray monopulse tracking system using 4 feeding horn antennas is well matched from 75 GHz to 90 GHz, and the isolation is secured by more than 10 dB. Finally, the proposed system shows the tracking range of 5.98 degrees and the tracking error range was 0.02 degrees.

• Journal of electromagnetic engineering and science
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• v.17 no.3
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• pp.120-125
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• 2017

A satellite communication (Satcom) antenna mounted on a moving platform provides a controlled heading that enables a geosynchronous satellite to communicate with the ground. A monopulse tracking method is effective for antenna control on a vehicle when it vibrates severely. However, this method has unexpected obstacles and its control performance is insufficient. To improve its control performance, the control command and monopulse error, the signal delay, and the radome effect are evaluated through tests. The authors then propose a method to transform the antenna error from 3D coordinates to 2D antenna coordinates. As a result, the antenna control performance is improved. As indicated in this study, examining antenna systems using the monopulse method on moving platforms is possible by understanding the antenna test process.

• 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.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.4
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• pp.380-386
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• 2014

In this paper, a higher-order mode coupler using coaxial-structure waveguide for Ku-band monopulse satellite tracking is proposed. The proposed higher-order mode coupler is built in a coaxial structure for compactness and weight reduction, making it suitable for mobile tracking systems. The inner circular waveguide of coaxial-structure is used to extract the fundamental mode signal and the high-order mode signal is extracted from the four slots of the outer circular waveguide and then transmitted via given stepped rectangular waveguide structure. The simulated results show that proposed higher-order mode coupler covers 250 MHz(12.75 GHz ~ 13.00 GHz) bandwidth with return loss and insertion loss characteristics. The antenna patterns of fundamental mode and higher-order mode applicable to monopulse tracking are generated successfully. Designed higher-order mode coupler using coaxial waveguide structure for Ku-band is expected to be used for high precision monopulse satellite tracking systems.