• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.729-736
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• 2011

In this paper, we propose a varactor-diodeless voltage-controlled oscillator operating at X-band, and verify the possibility of applying to a receiver for microwave radar signal detection applications. The proposed VCO is realized by only single RF BJT device as a varactor diode is substitued by a intrinsic collector-base PN-junction of the active device which is used to generate negative resistance. The fabricated VCO meets the specification of the receiver, which has a 11.20~11.75 GHz tuning bandwidth with respect to the tuning voltage, 1.0~7.0 V, output power of 9.0~12.0 dBm and linear frequency tuning performance.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.75-82
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• 2001

In this paper, a transmitter and a receiver using a Gunn diode and SBD was designed and fabricated in X-band. This system detects Doppler shift signal reflected by moving target through the homodyne detection, which is Doppler radar sensor for the measurement of the velocity of moving target. By the experimental results, the oscillating condition of the transmitter was satisfied at about the half wavelength between the supporting post of the Gunn diode in the waveguide and the waveguide short. And using the fabricated Doppler radar sensor, the velocity measurement deviation of moving target was 1.24%.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.31-36
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• 2022

Recently, drones are being used in various fields, and drone technology is also developing. The risks of drones are increasing, then technology to detect drones is important. However, it is extremely difficult to detect and recognize drones due to the low level radar cross section of the commercial drones. In this paper, a signal processor structure that was mounted the miniaturized and light-weighted was designed. in order to process large amounts of data in real time, parallel processing was performed for each channel and an algorithm was applied to shorten the operation time in each step. As a test of verifing the detection performance through test, it was confirmed that the structure design works in real time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.913-920
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• 2017

In this development, By using the phase array antenna, the beam around was electronically revolved and the marine fixed type radar of which the detection is possible was made and the check around was tested. There are the risk of the corrosion because of the abrasion of the axis of rotation and salinity with the way that the existing marine pulse radar detects the check by using the mechanical rotation. Besides, the maintenance cost of the magnetron gets to happen by using the detection signal. In this development, The fixed type radar of the low output which revolves electronically around the beam by using the radar signal processing method of the phase array antenna using the phase shifter and FMCW(Frequency Modulation Continuous Wave) method was made. And by using the fixed type radar, the check detection test was conducted.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.3
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• pp.246-251
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• 2023

RADAR(Radio Detection and Ranging) is an important system for surveillance and reconnaissance by detecting a reflected signal which obtains the range from the radar to the target, and the velocity of the target. The magnitude of the reflected signal varies due to the radar cross section of the target, characteristic of the transmission and reception antenna, distance between the radar and the target, and power and wavelength of the transmitted signal. Thus, the RCS is the important characteristic of the target to determine if the target can be observed by the RADAR system. It is based on the material and shape of the target. We have measured the reflection signal of a simple square-shaped (20 × 20 cm) target made of a new material, a gallium-based liquid metal alloy and compared that of well-known metals including copper, aluminum. The magnitude of reflected signal of the aluminum target was the largest and it was 2.4 times larger than that of the liquid metal target. We also investigated the effect of the shape by measuring reflectance of the F-22 3D model(~1/95 ratio) target covered with/without copper, aluminium, and liquid metal. The largest magnitude of the reflected signal measured from side-view with the copper-covered F-22 model was 2.6 times greater than that of liquid metal. The reflectance study of the liquid metal would be helpful for liquid metal-based frequency selective surface or metamaterials.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.10
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• pp.966-980
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• 2011

Radar receiving echo signal provides target information - range, velocity and position by signal magnitude and Doppler shift, which are determined by target reflection characteristics and target maneuver. Target angle error is extracted from the magnitude ratio of difference channel to sum channel. In this paper, we introduce a radar Return Signal Simulation Equipment(RSSE) which is implemented for the purpose of performance analysis and evaluation of phased array multi-function radar(MFR). It generates multi-target environment with jamming signals using MC-DDS (Multi-Channel Direct Digital Synthesis), and has scalability by using the efficient hardware configuration. The performance of the developed RSSE has been evaluated under various test environments. Especially, we proved that required target detection performance is achieved by RSP(Radar Signal Processor) interfaced RSSE configuration.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.2
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• pp.214-217
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• 2013

In this paper, we proposed an automatic threshold control method for radar warning receiver. Considering the noise level of the environment, this technique can effectively adjust sensitivity level of radar warning receiver and can offer more accurate radar information for aircraft pilot in noisy circumstances.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.890-893
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• 2014

In this paper, we present a signal processing algorithm for a marine radar system, in which the evaluation of probability of collision as well as target detection and tracking are performed. Moreover, the digital signal processor that implements the algorithm is proposed. As simulation environment, a mechanically scanning antenna utilizing FMCW signal is used, conducting the beamforming operation with 1 degrees intervals. Test board consists of DSP chips and FPGA, which enable the implemented system to operate in real-time.

• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.1
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• pp.47-58
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• 2011

MTI filter is used to separate target signal from clutter in many radar signal processing. By suppressing clutter before CFAR detection, the detection performance can be improved. As a radar system designed, a design engineer generally takes averaged SNR and CNR into account and does not include the effect of MTI filter's frequency response. In practice, when the signals including clutter are pass through the filter, SNR is widely varying according to target velocity and CNR is also varying according to clutter center frequency and spectrum spreading. In this paper, we have derived the relationship between the MTI filter's frequency response and a target's velocity and a clutter's spectrum characteristics. With the variation of SNR and CNR at the filter output, the detection performance of CFAR has been analyzed by the simulation and has made certain of their influences on the performance.