• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.143-144
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• 2011

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.511-512
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• 2013

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.914-923
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• 2009

Helix antennas have been widely applied to satellite TT&C, data communication and GPS receiver systems onboard military, remote sensing and communication purpose satellites. The helix antennas are known to be convenient to control impedance and radiation coverage characteristics with a maximum directivity in satellite z-axis. Waveguide horn is commonly used for radar system that needs ultra-wideband pulse for exploration ground radar and electromagnetic disability measurement etc. It has high efficiency and low reflection characteristics provided by the low-profile shape and suppressed radiation distortion. In this paper, a waveguide horn structure incorporated with helix antenna design is proposed for satellite applications that require ultra-wideband pulse radar and high rate RF data communication link to ground station over wide coverage area. The main design concern is to synthesize variable beam forming pattern based on modified horn-helix combination helicone structure such that multi-mission antenna is implemented applicable for TT&C, earth observation, high data rate transmission. Waveguide horn helps to reduce the overall antenna structure size by introduction fold type reflector connected to the tapered helix antenna. The next generation KOMPSAT satellite currently under development requires high-performance precision attitude control system. We present an initial design of a hybrid hern-helix antenna structure suitable for efficient RF communication module design of multi-purpose satellite systems.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.301-304
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• 1999

밀리미터파 대역의 아날로그 광전송을 위한 진행파형 (travel ing wave, TW) 전계흡수 광변조기 (electroabsorption modulator, EAM)와 광수신기의 설계에 대해 발표하고자 한다. TW EAM 및 TW 광수신기의 일반적인 형태인 ridge-type의 co-planar waveguide (CPW)구조에서의 마이크로파의 전송특성을 3차원 FDTD로 분석하여 광파와 전파의 속도 정합 등을 이루는 최적화 구조를 설계하였다. TW EAM의 경우 광세기 변조의 비선형 응답특성에 있어서 마이크로파 손실과 소자길이가 RF 신호의 혼변조 왜곡 (intermodulation distortion)과 SFDR (spurious free dynamic range)성능에 미치는 영향도 이론적으로 조사하였다. TW PIN 광수신기의 경우 광파와 마이크로파의 속도정합의 영향과 이전에는 고려되지 않았던 photo-generated 전송자의 진성 영역에서의 transit time이 광수신기의 밴드 폭에 미치는 영향을 분석하여 최적화 설계하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1223-1231
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• 2010

The design is presented for a SATCOM antenna capable of simultaneous multi-band (X/Ku/Ka-Band) communications without replacement of feed horns or change of other parts in the application as a ground satellite terminal for large data transfer. The antenna is the offset configuration and consists of a dual-band(X/Ka-band) feed horn, a single-band(Ku-band) feed horn, a frequency selective surface(FSS) sub-reflector and a parabolic main-reflector. The antenna has a main reflector defining a prime focus and a frequency selective surface sub-reflector defining an image focus. A dual-band feed and a single-band feed are provided at each of the prime focus and image focus. The antenna is designed using 3D EM simulator and the gains measured in X/Ku/Ka-band of the complete antenna assembly is more than 31.6dBi, 36.8dBi, 40.8dBi, and the cross polarization is 21.7dB, 26.6dB, 25.2dB, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.195-202
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• 2015

As satellite communications services are showing gradual growth, so are the needs for dual or tri-band antennas greater than performance of conventional single-band antennas. In this paper, a simultaneously operable tri-band antenna for SATCOM(Satellite Communications) is proposed. It is different from conventional methods of implementing tri-band through replaceable horns, while it is designed with a tri-band feed assembly composed of corrugated and dielectric horns and reflectors of gregorian type to transmit and receive tri-band of X, Ku and Ka band simultaneously. And simulated and measured values were compared and analyzed for characteristics of the proposed antenna. In the results, radiation patterns of the proposed tri-band antenna were close to the simulated ones and also met specifications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.823-830
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• 2010

This paper deals with a coaxial-to-waveguide transition generating circularly polarized wave to be connected with horn antennas. By combining vertical coaxial fed structure, back-short and the polarization twisting structure, the circular polarization is successfully generated in the waveguide. The designed and implemented transition shows that the present structure can significantly reduce the size of the antenna part at X-band.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.828-834
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• 2023

In this paper, we studied an antenna that forms a wide beam width by applying a horn-shaped reflector to a patch array antenna. To implement a wide beam width, three patches were arranged in each of the four directions on a square microstrip substrate, and a horn-shaped reflector was applied to the rear of the array antenna. Through this structure, the vertical beam pattern formed from the patch was converted to a diagonal direction, and as a result, the beam widths formed in each of the four sectors were added to create a wide beam width close to a hemisphere. The proposed antenna was studied for application to UAV(unmanned aerial vehicle), and the simulation test results confirmed that the 4.5 dBi beam width was 146.8°.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.10 s.113
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• pp.1000-1006
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• 2006

In this paper, the gain of the square hem antenna is enhanced with $3{\times}3$ latticed aperture. In order to get the uniform field distribution on the aperture, the different thicknesses of dielectric plates for the phase compensation are inserted into the center and the edge of the aperture respectively. The proposed horn antenna is designed at 12.5 GHz band, and then the analysis of the field distribution on the aperture is performed by using FDTD method. The radiation pattern is also calculated from the analysis. Based on the measured data, it is verified that the gain of a horn antenna with latticed aperture is 18 dBi and this is 2 dB gain enhancement compare with a normal horn antenna without latticed aperture.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.3
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• pp.95-100
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• 2007

In this paper, a twice folded TEM horn antenna for 70 kV impulse high power system is proposed. The length reduction of 50 % is achieved by folding a conventional TEM horn antenna twice. The array elements are fed by the stripline power divider using the Chebyshev transformer. The power divider feeds four TEM horn antenna elements with an in-phased uniform power, and it covers a wide bandwidth ($150\;MHz\;{\sim}\;768\;MHz$, VSWR<2.0). Considering the air breakdown at peak 70 kV impulse, the proposed antenna maintains the 25 mm gaps between conducting plates. The dimension of the twice folded horn antenna is $1730\;{\times}\;1600\;{\times}\;300$ (mm3), and the operating frequency is from 152 MHz to 750 MHz under 10 dB return loss. The peak gains are measured from 6.77 dBi to 10.70 dBi at $400\;MHz\;{\sim}\;750\;MHz$.