• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1984.10a
• /
• pp.66-69
• /
• 1984

A corrugated eiliptical horn which has the aperture dimensions of 60 x 30mm is designed and investigated experimenttally for 11Ghz - 13Ghz band. Experimental result is that the constructed horn produce on eiliptical far-field pattern with ratio of 1.63:1 - 1.81:1 for half-power beamwidth.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.11
• /
• pp.1672-1678
• /
• 2022

In this paper, the relay antenna was designed in consideration of the performance of the 28GHz band 5G mobile communication relay horn antenna, such as radiation pattern and return loss. A horn array for 5G mobile communication repeater was designed by arranging the antenna elements in phase, and the performance was analyzed. Unlike conventional WCDMA (3G) and LTE (4G), in millimeter wave band communication, high path loss occurs between transmission and reception. In the design of a 5G millimeter wave horn antenna, antenna performance such as isolation and gain between antenna elements as well as gain and bandwidth of the antenna must be additionally considered. The antenna gain of the single horn antenna (1×1) and the array horn antenna (2×4) in the 28GHz band is about 10.44d Bi and 19.58dBi, respectively, and the return loss is designed to be less than -18dB. It has proven its validity and has been shown to be suitable for application to 5G mobile communication relay system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.5
• /
• pp.666-670
• /
• 2014

TEM Horn antenna is typically used in HPEM area. It is necessary to apply a high voltage of the antenna for radiating HPEM. Then, it is necessary to insulate essentially of applying a high voltage to the antenna. At this time, radiation pattern and gain of the TEM Antenna is changed. For this reason, it is necessary to analyze changing characteristics by using simulation. In this paper, I analyzed the radiation pattern of the antenna in accordance with the lens and insulating material. As a result, it was observed that the value of the gain is changed in accordance with the frequency. The lens is used for the antenna, the gain characteristic is improved.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.733-736
• /
• 2005

This paper presents the design of two antennas for the Dual-channel Radiometers for Earth and Atmosphere Monitoring (DREAM) the main payload, will be launched at NARO space center in Korea in 2007. The antennas are designed to meet stringent requirements of a very high beam efficiency, good pattern symmetry, and low VSWR, at 23.8 GHz and 37 GHz bands. Corrugated horn antennas are used. The simulation results of the electrical performance are presented.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.4
• /
• pp.24-31
• /
• 1998

The far-zone magnetic field patterns of a E-plane horn antenna with various edge structures are analyzed using UTD. The ray tracing method is used to lacate the shadow boundaries, and then GO and UTD are utilized to evaluate the incident, reflected, diffracted, surface diffaracted, and the second order diffracted, diffracted-reflected, and diffracted-reflected-diffracted waves existing in each region of interest. By doing this, we analyzed the effects of flanges or caps connected on the edge of a horn antenna on the side lobe and back lobe levels. Also, the validity of this paper is proved by comparing the analytical results with those of measurement and method of moment presented in the reference.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.9 no.2
• /
• pp.127-134
• /
• 2017

Vortex Induced Vibration (VIV) is a typical flow-structure interference phenomenon which causes an unsteady flow pattern due to vortex shedding at or near the structure's natural frequency leading to resonant vibrations. VIV may cause premature fatigue failure of marine risers and pipelines. A test model was carried out to investigate the role of a stationary fairing by varying the caudal horn angle to suppress riser VIV taking into account the effect of wake interference. The test results show significant reduction of VIV for risers disposed in tandem and side-by-side. In general, fairing with a caudal horn of $45^{\circ}$ and $60^{\circ}$ are efficient in quelling VIV in risers. The results also reveal fairing can reduce the drag load of risers arranged side-by-side. For the tandem configuration, a fairing can reduce the drag load of an upstream riser, but will enlarge the drag force of the downstream riser.

• Transactions of Materials Processing
• /
• v.21 no.2
• /
• pp.119-125
• /
• 2012

The present study addresses a direct patterning process on a plastic film using ultrasonic vibration energy. In this process, a tool horn containing micro-patterns is attached to an ultrasonic power supply, and is used with ultrasonic vibration to replicate micro-patterns on the surface of a plastic film. To improve the replication characteristics of the micro-patterns, the effect of the die shape of the ultrasonic patterning process was investigated with respect to the flow direction control. Finite element analyses were performed to predict the flow characteristics of the polymer with variations in die design parameters. Experiments were conducted using the optimally-designed die, from which it was possible to attain much improved pattern replication.

• Journal of the Society of Naval Architects of Korea
• /
• v.44 no.3 s.153
• /
• pp.228-237
• /
• 2007

The flow characteristics around a horn-type rudder behind an operating propeller of a high-speed large container carrier are studied through a numerical method in fully wetted and cavitating flow conditions. The computations are carried out in a small scale ratio of 10.00(gap space=5mm) to consider the gap effects. The Reynolds averaged Navier-Stokes equation for a mixed fluid and vapor transport equation applying cavitation model are solved. The axisymmetry body-force distribution technique is utilized to simulate the flow behind an operating propeller. The gap flow, the three-dimensional flow separation, and the cavitation are the flow characteristics of a horn-type rudder. The pattern of three-dimensional flow separation is analyzed utilizing a topological rule. The various cavity positions predicted by CFD were shown to be very similar to rudder erosion positions in real ship rudder. The effect of a preventing cavitation device, a horizontal guide plate, is also investigated.

• The Korean Journal of Pain
• /
• v.9 no.2
• /
• pp.326-335
• /
• 1996

Background: Though a number of studies have described the distribution of substance P(SP)-like immunoreactivity in the spinal cord, they have been focused on lamina I and II of the dorsal horn and there are little morphological studies on the topographic distribution and ultrastructure of the SP immunoreactive neurons especially in the ventral horn of the spinal cord. this study was conducted to identify distribution pattern of SP immunoreactive neurons and to difine the synaptic organization of their processes in ventral horn of the thoracic cord of the cat by preembbeding immunocytochemical method using SP antiserum. Methods: Five adults cats of either sex were used and deeply anesthetized by intramuscular injection of ketamine. After removal of the spinal cord, samples of thoracic cord were taken and placed in fresh fixative at $4^{\circ}C$ for 2 hours. Transverse sections $50{\mu}m$ thick were processed using the preembbeding immunocytochemical method and incubated consecutively in the specific primary antibody and the 10% normal goat serum, the rabbit anti-substance P antiserum, the biotin-labelled goat anti-rabbit IgG and finally the avidin-biotin-peroxidase complex. The processed tissue sections were throughly washed and stained in the black with 1% uranyl acetate. Section were examined on a electron microscope. Results: 1) SP immunoreactive neurons were observed in the gray matter around central canal. 2) In lamina I and II SP immunoreactivity was observed in both myelinated and unmyelinated nerve fibers, but in ventral horn only in the unmyelinated nerve fibers. 3) SP immunoreactive axon terminals with small round and large dense core vesicles made chemical synapses onto the dendrites of motor neurons in the ventral horn. Conclusion: SP immunoreactive neurons might play an important role in modulation of motor neurons in the ventral horn of the thoracic cord of the cat.

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