• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.7
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• pp.955-961
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• 2021

In modern warfare, the importance of electronic warfare, which carries out a mission that using radio wave to find out enemy information or to protect ally information, has increased. Radar jamming technique is one of the most representative techniques of EA(Electronic Attack), it disturbs and deceives enemy radar system in order to secure ally location information. Velocity deception jamming technique, which is one of the radar jamming techniques, generally operate against pulse-doppler radar which use doppler effect in order to track target's velocity and location. Velocity Deception Jamming Technique can be implemented using DRFM(Digital Radio Frequency Memory) that performs Frequency Modulation. In this paper, I describe implementation method of VGPO/VGPI(Velocity Gate Pull-Off/Pull-In) velocity deception jamming technique using phase-sampled DRFM, and verify the operation of VGPO/VGPI velocity deception jamming technique with board test under signal injection condition.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.4
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• pp.569-576
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• 2010

Jamming simulator has developed for the purpose of the test and evaluation on the electronic protection capabilities of the tracking radar onboard ship. This simulator has the capabilities to generate and radiate the jamming signals against the radar as well as those to receive, analyze and identify the radar signals at a real sea environment. The limited space of ship superstructure has led to the serious distortion caused by the ring around phenomenon that some sidelobes of the jamming beams were coming back to the receiving antenna. In this paper, we have proposed the methods to eliminate the ring around. First, we have inserted the groove metal screen between transmitting and receiving antennas. Second, we have used the PRI(Pulse Repetition Interval) tracking loop to control the switching timing of the input radar and the output jamming signal. Finally, we have demonstrated the performance and effectiveness of the proposed methods through the sea trial.

• 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 Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.12
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• pp.1105-1111
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• 2016

In modern warfare, various target tracking radars are used for target location tracking. So, the importance of EA radar jamming technique which disrupt enemy target tracking radar in oder to neutralize tararget location tracking has increased. VGPO/I jamming is a base technique of EA(Electronic Attack), it is possible to operate to pulse-Doppler radar. In this papar, we develop VGPO/I jamming technique that can apply to phase sampled DRFM by using phase information and verifiy through simulations.

• Journal of Convergence for Information Technology
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• v.10 no.6
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• pp.14-18
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• 2020

In this paper, when two sets of cross-eye jammer antennas are installed vertically to jam a monopulse radar, the jamming effects according to the jammer's phase difference, amplitude ratio, and radar angle of engagement are analyzed. The phase difference and amplitude ratio of the cross-eye jammer can be adjusted in the jammer, but since the angle of engagement is relatively determined by the radar, it is very important to respond to changes in the angle of engagement. The orthogonally deployed jammer antennas can be considered as a good way to increase the jamming effect while minimizing the hardware configuration, and the jamming effect is analyzed while changing the angle of inclination from 0° to 360°. This jammer greatly improves the jamming effects at the angles of incidence 45°~135° and 225°~315°, compared to a single jammer. And it is expected to be useful in the design of cross-eye jammers for military aircraft and ships.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1201-1207
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• 2005

When the isolation between transmitter and receiver in Electronic Warfare equipment is not sufficient, the radiated noise jamming signal from the transmitter feeds back into the receiver and interferes with receiving radar pulse signal. Therefore pulse jamming and noise jamming can't be performed together in the same frequency bands. In this paper, we present a time-sharing TX/RX control technique of the switch matrix which inhibits the transmission of noise jamming signal by using the predicted gate of pulse train and also makes the corresponding channel filter operate to receive the radar pulse signal during the predicted gate pulse. This technique was implemented by EPLD and confirmed by experiment. The proposed technique enables the pulse jamming and the noise jamming to be simultaneously executed in multiple jamming environments.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.5
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• pp.452-458
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• 2020

In this paper, the contents of the development of RESS(Radar Environmental Signals Simulator) for the test of active phased array multi-function radar are described. The developed RESS can simulate multiple target environments, such as target/jamming/missile response/cluster signals, by using received radar operational information and simulated scenario. It can also modulate frequency, phase, gain, timing on all waveforms operated by multi-function radar and simulated two targets and one jamming in the beam. The RESS can be used to perform functional and performance verification of the active phased array multi-function radar with sub-array receiving structures.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.574-579
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• 2023

The radar flight test has many restrictions on simulating various targets, clutter and jamming signal. Therefore, in this study, a radar HILS system that performs a radar operation simulation function according to an operation scenario was developed. Radar HILS simulates the radar mission environment through radar beam operation simulation, radar operation control, simulated signal generation, and flight attitude simulation.. HILS generates and modulates simulated target signals(single, multiple targets) containing radar mission environments(clutter, jamming etc.) based on flight scenarios, and transmits them to AESA radar over RF. And Scenario-based radar performance was verified by detecting simulated targets and confirming detection results.

• Journal of Convergence for Information Technology
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• v.11 no.8
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• pp.23-28
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• 2021

In this paper, we analyze the tracking errors of monopulse radar according to the JSR of retrodirective cross-eye and radar skin return signals. The cross-eye jammer gain(G_c) is used to calculate the radar tracking errors, and the relationship between the jammer gain and the JSR is represented mathematically. We analyze the radar tracking errors by varying the tracking angle and JSR. Analysis results of the phase difference(ϕ) and amplitude ratio(a) between the two jammer signals and the changing JSR show that the closer the phase difference of the two jammer signals is to 180, the greater the tracking error and it shows that if the JSR is above 20dB, the tracking errors no longer increase. This work presents an effective utilization of retrodirective cross-eye jammers through various tracking error analyses based on the JSR, tracking angles, two-jammer phase differences and amplitude ratios of two-jammer signals.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.6
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• pp.546-554
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• 2015

Ultra-wideband(UWB) radar is widely used in many penetration radar applications, such as ground-penetrating radar and foliage-penetrating radar, because it has many advantages in detecting concealed objects. One type of UWB radar system is random noise radar, which many be robust to jamming environment. However conventional random noise radar requires high-speed analog-to-digital convertor(ADC) for matched filtering. In this thesis, a pseudo-random noise radar system that maintains anti-jamming characteristics but does not require high-speed ADC is researched. and The UWB system is implemented in a low frequency system, and its performance has been demonstrated by experiment, which proves the concept of the proposed pseudo-random noise radar system.