Ka-밴드 도파관 슬롯 배열 안테나 설계와 제작

具然健,黃志煥 홍익대학교 산업기술연구소 2002 産業技術 Vol.12 No.-

This paper presents a waveguide slot 16x16 array antenna with diaphragm for 37.5~38.5 GHz frequency band. At first, the radiation characteristics of longitudinal slots on a broadside of a waveguide have been examined. Diaphragms are used to control the impedance and to minimize the return loss of the structure. A 20 dB Chebyshev array of 16 waveguide slots has been designed by optimizing the positions and sizes of the diaphragms and the slots. Then, a serial feeding system with π-junction power dividers has also designed to get a 20 dB Chebyshev power distribution. We used the HFSS for full-wave analysis and the MW Office for equivalent circuit simulations. The 16x16 slot array antenna, which was designed for a Fixed Wireless Access System at 38 GHz frequency, gives an antenna gain higher than 30 dBi. A slot array antenna was manufactured using a computer controlled milling technique, and measured for the return loss and the antenna pattern.

내곡면에서의 마이크로스트립 어레이 안테나의 복사 패턴에 관한 연구

具然建,高光泰,李正秀 弘益大學校 1988 弘大論叢 Vol.20 No.2

The radiation pattern of microstrip array antennas attached on the inner side of a curved surface is studied analytically. The calculated values based on the radiation theory and the measured values are in good agreement. It is verified that the radiation pattern becomes broaden as the radius of curvature decreases.

GaAs-FET를 이용한 S-Band 저잡음 증폭기의 설계에 관한 연구

具然健,高光泰 弘益大學校 1985 弘大論叢 Vol.17 No.2

In this paper the two-port network analysis of microwave amplifier and the design method of low-noise amplifier are described. And when this theory is applied to an S-band amplifier with GaAs-MESFET and narrowband design at 4.0 GHz, the experimental results are conformed with the theoretical values. The amplifier achieves 1.2 GHz 3 dB-bandwidth in band and 12.5 dB gain with 2.21 dB noise figure at 4.0 GHz.

마이크로스트립 대역통과필터의 設計

具然健,金斗根,李漢明 弘益大學校 1983 弘大論叢 Vol.15 No.2

A procedure for designing a band-pass filter of quarter-wavelength microstrip resonator with interdigital array is presented. After the design curve is determined experimentally by the resonance phenomena of several pairs of resonators, the microstrip interdigital filter for center frequency of 700 MHz and fractional bandwidth of 20% is designed. It is obtained that the fractional bandwidth is 19.43%, centered at 695 MHz. An experimental results show that the computed values almost agree with measured values except for the ripple which is negligible.

運動하고 있는 誘電體圓柱에 의한 平面電磁波의 散亂

具然健 弘益大學校 1981 弘大論叢 Vol.13 No.-

The scattering of electromagnetic waves with a dielectric column which is moving uniformly in a perpendicular direction to its axis was analyzed. A homogeneous dielectric for a moving boundary, an arbitrary polarization for the incident plane wave, and ka<<1 were assumed. It was found that for E-waves, the total scattering cross sections were the functions of relative velocity and dielectric constants and scattering patterns were circles of their centers shifted to the opposite of the moving direction and of their radii to be dependent on the relative dielectric constants, and for H-waves, total scattering cross sections were varied as relative velocity and relative dielectric constant and scattering patterns of constant moving velocity were dispersed as relative dielectric constants decreased and those of constant relative dielectric constants were also dispersed as relative velocity decreased. Ⅰ. 緖 論 Ⅱ. 理 論 Ⅲ. 檢 討 Ⅳ. 結 論 The scattering of electromagnetic waves with a dielectric column which is moving uniformly in a perpendicular direction to its axis was analyzed. A homogeneous dielectric for a moving boundary, an arbitrary polarization for the incident plane wave, and ka<<1 were assumed. It was found that for E-waves, the total scattering cross sections were the functions of relative velocity and dielectric constants and scattering patterns were circles of their centers shifted to the opposite of the moving direction and of their radii to be dependent on the relative dielectric constants, and for H-waves, total scattering cross sections were varied as relative velocity and relative dielectric constant and scattering patterns of constant moving velocity were dispersed as relative dielectric constants decreased and those of constant relative dielectric constants were also dispersed as relative velocity decreased.

3차원으로 배열된 마이크로스트립 어레이 안테나의 전력 패턴에 관한 이론적 해석

具然健,高光泰 弘益大學校 1989 弘大論叢 Vol.21 No.2

In this study, the radiation pattern of a conformal microstrip array antenna attached on a curved surface is theoretically analyzed. When the element of an array antenna changes its radiating direction according to its position, the existing theory could not be applyed on the analysis of their radiation pattern. So, an analysis method using translation and rotation of the coorinate system for each patch is discribed here to calculate the total radiation pattern of the array antenna. The result of this method, through a computer simulation, is presented.

Microstrip-Log-Periodic 안테나의 Near-Field 特性

具然健,金將起 단국대학교 1977 論文集 Vol.11 No.-

A new class of antenna using a double ridged-waveguide type microstrip to reduce the size of Logarithmically periodic dipole array (LPDA) antenna is studied on electrical characteristics. When all the linear dipole elements of a LPDA antenna are replaced by the foreshortened dipoles, the resulting structure still maintains the frequency-independent characteristics of Log-periodic structures but suffers moderate loss in gain and directivity.

軸과 垂直方向으로 運動하는 誘電體圓柱에 의한 斜入射 電磁波의 散亂

具然健,金斗根 弘益大學校 1984 弘大論叢 Vol.16 No.2

The scattering of a plane electromagnetic wave incident obliquely upon the surface of a perfect dielectric column with a uniform velocity in the perpendicular direction to its axis is analyzed nummerically. The scattered fields are computed according to the postulates of special relativity. The angle distribution of the scattered power, the total scattering cross sections and the radar cross sections are illustrated as the function of the incident angles of a plane wave and the relative velocity of a dielectric column.

도심 지역 전파 전달 특성 해석

구연건,이병훈 弘益大學校 科學技術硏究所 1997 科學技術硏究論文集 Vol.8 No.-

Characteristics of microwave reflections and diffractions in an urban crossroad is presented in this thesis utilizing geometrical optics(GO), Uniform geometrical theory of diffraction(UTD) and ray tracing technique. At first, three-dimensional multiple paths between a transmitter and a receiver at various line-of-sight(LOS) or out-of-sight(OOS) positions in the crossroad were traced using the image method. The multiple paths include direct incidence, specular wall and ground reflections and corner diffractions. Then, signal path losses to the receiver at various positions in the crossroad were computed using GO, UTD and total path lengths and reflection angles. The appropriate number of reflection for numerical convergence was computed and the effects of polarization, frequency and dielectric constant of the wall and ground on the pathloss to LOS and OOS positions are also studied. The accuracy of this method is verified by the experimental measurement in a constructed cross road. It was also applied in more complicated road structures.

振動하는 導體平面에 의한 電磁波散亂

金斗根,具然健 弘益大學校 1982 弘大論叢 Vol.14 No.2

The signal scattered from a moving target is used to be analyzed through classical FM theory to extract the Doppler results. This method can easily be applied to the motion with uniform velocity, but is not suitable when the target motion is vibrational. As a different approach, the motional properties of the target could be identified by correlating the reflected wave with the transmitted, incident wave to derive the scattered power difference from the differently vibrating objects. A simple application to the perfectly conducting infinite plane scatterer with sinusoidal oscillation is studied.