• 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 Convergence for Information Technology
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• v.12 no.4
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• pp.9-13
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• 2022

In this paper, the tracking error of monopulse radar caused by cross-eye jamming using terrain bounce is analyzed. Cross-eye jamming is a method of generating an error in a radar tracking system by simultaneously transmitting two signals with different phases and amplitudes. When the monopulse radar receives the cross-eye jamming signal generated by the terrain bounce, a tracking error occurs in the elevation direction. In the presence of multipath, this signal is a combination of the direct target return and a return seemingly emanating from the target image beneath the terrain surface. Terrain bounce jamming has the advantage of using a single jammer, but the space affecting the jamming is limited by the terrain reflection angle and the degree of scattering of the terrain. This study can be usefully used to protect ships from low-altitude missiles or aircraft in the sea.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.93-99
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• 2016

In this paper, higher order coupler using small size waveguide which applicable for mobile Ku-band multimode monopulse satellite tracking antenna system, has been designed, implemented and tested. Proposed higher order mode coupler adopts a coaxial structure for low profile characteristic considering installation property to mobile satellite terminal system. In addition, by using proposed coupler, extracted tracking error signal pattern has measured and confirmed that required tracking accuracy is satisfied in desired frequency band. In the future, proposed coupler could utilize for multimode monopulse satellite tracking system for high tracking accuracy.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.71-76
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• 2014

In this paper, we proposed the 1-channel monopulse receiver which has the new configuration and described the operation procedures. Also, we compared and analyzed the proposal receiver and the general 3-channel monopulse receiver. As a result, it is apparent that the monopulse ratio of the proposal receiver is equal to that of the 3-channel monopulse receiver. The proposal receiver achieve the simple receiver configuration and the simple tracking procedures, as contrasted with the 3-channel monopulse receiver. Also, the proposal receiver has advantages in terms of size, weight, cost and power. Because the proposal monopulse receiver require 1-channel receiver and need not the signal processor in comparison with 3-channel monopulse receiver which require 3-channel receiver and need the signal processor.

• Korean Journal of Optics and Photonics
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• v.29 no.1
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• pp.1-6
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• 2018

In this study, ray-tracing software was used to calculate the optical path length of an optical system. Using the optical path length, the optical phase, group delay (GD), group delay dispersion (GDD), and third-order dispersion (TOD) of the optical system were obtained. Pulse compressors using a prism pair or grating pair were designed to compensate the GDD of a real optical system for a femtosecond fiber laser. Also, a pulse stretcher using a grating pair with lenses or mirrors was designed. The results of this study can be used to calculate the dispersion of an optical system and optimize the performance of an ultrashort pulse laser optical system.

• 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 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 Communications and Information Sciences
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• v.37A no.12
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• pp.1145-1151
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• 2012

In this paper, we propose an unambiguous binary offset carrier (BOC) correlation function with narrow main-peak width for BOC code tracking. Specifically, we first separate a subcarrier pulse into two rectangular pulses, obtain the associated partial correlations, and re-combine the partial correlations to yield the unambiguous correlation function with narrow main-peak width. From numerical results, it is demonstrated that the proposed correlation function provides a significant performance improvement over the conventional correlation functions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.59-64
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• 2024

The small tracking radar randomly changes the transmission period to avoid deceptive signals such as RGPO (Range Gaet Pull Off) operated on the target. Since the code repeats after a specific section, it becomes difficult to avoid a deceptive signal when the repetition is exposed. In this paper, a more realistic transmission pulse code is generated by adding random code generation through FPGA and system white noise. We present the research results of code generation that generates PRF that can avoid repetition while using pseudo-random code in EPROM using FPGA. Also, the result of designing random PRF pulse was confirmed by applying it to tracking radar.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.77-86
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• 2006

Usually, a tracking-gate of the tracker is used to track the target radar signal in the active ECM system. In this paper, we propose the feed-back tracking-gate filtering method. The designed method applies a tracking-gate of the tacker to the ECM system's receiver as a rejection or pass filter selected by the receiver's purpose, and the specific target signals can be passed or rejected though this tracking-gate filter. Thus, the number of input signals within the receiver's search band is minimized owing to this filter except the target signals. In conclusion, the EW equipment's reaction time can be reduced and the error value about the target signals can be lower than the previous methods'.