• The Journal of the Acoustical Society of Korea
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• v.2 no.1
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• pp.59-66
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• 1983

본 논문은 랜념배열 안테나에서 위치함수의 확률분포함수가 정규 Gaussian 분포가 되도록 사다 리 계층법과 등면적 분포법이란 새로운 방법을 제시하였고 이를 선형과 판형 배열 안테나로 설치하여 그의 방사특성을 컴퓨터에 의해 계산하고 합성한 것이다 측정된 결과를 Monte-Carlo 법에 의한 랜념배 열 안테나와 균일 간격으로 배열된 안테나에 의한 측정결과와 비교한 결과 부로부레벨은 등면적 분포법 에 의한 배열안테나에서 가장 낮았으며 소자수가 많을수록 낮아졌다. 또한 빔폭은 확률밀도함수와 operture 길이에 의존함을 알 수 있다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.3
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• pp.209-216
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• 2003

We design and fabricate slot array antenna for BMWS(Broadband Multimedia Wireless System) applications. This paper presents a simple feed structure, which consists of two horns and a parallel-plate waveguide, because antennas operating at 40.5 GHz~43.5 GHz have considerable feeding losses. The simple feed structure has the advantages of high-efficiency and mass-production. The fabricated antenna has a gain of 25.8 dBi with a sidelobe level below -18 ㏈ and a 3 ㏈ beamwidth of approximately 3$^{\circ}$ in the E-plane. In case of H-plane, a 3 ㏈ beamwidth is 17$^{\circ}$ and a sidelobe level is suppressed to below -27 ㏈. The experimental results are in good agreement with the simulation results. The authors expect that narrow 3 ㏈ beamwidth is obtained by combining a few proposed slot array antennas in parallel.

• Journal of Advanced Navigation Technology
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• v.11 no.1
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• pp.64-71
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• 2007

In this paper, we have designed and fabricated microstrip antenna of S-band for the wireless LAN and the ISM. It array $2{\times}2$ circular patch antenna elements at plane instead of conventional rectangular patch antenna elements. It optimized to size calculated of single patch antenna. The radiation elements distance is array $0.24{\lambda}$. The fabricated circular patch antenna decreased 8% of size compared to the conventional rectangular patch antenna. In the E-plane, designed circular microstrip patch $2{\times}2$ array antenna gain is 12.7[dBi], half power beam width is $40^{\circ}$ and in the H-plane, antenna gain is 12.1[dBi], half power beam width is $45^{\circ}$. Bandwidth is 250[MHz] (VSWR < 2).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.519-526
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• 2002

In this paper, a microstrip patch array antenna for a Doppler radar at 10.525GHz is desinged and fabricated. To be used for mobile radar system, the antenna is fabricated on a single layer laminate to resist a fire impact and is covered with the Teflon foam. To obtain the desired characteristics, the array antenna is designed 4$\times$8 array using a corporate 3-dB amplitude taper. Also, using square patch elements, the antenna can be converted to a circular polarized antenna later. The designed and fabricated array antenna has the reflection coefficient$({S_11})$ -53.498dB, the horizontal beam width of $10^{\circ}$, the vertical beam width of $18.8^{\circ}$, the gain of 21dBi, the bandwidth of 220MHz for VSWR<1.5 and a side lobe level of less than -17.5dB.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.10-15
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• 2007

Small size and low profile antenna for mobile vehicular-top-mounted is needed in satellite communication services such as DBS, Satellite Internet and VSAT. In middle latitudes, the development of an array antenna which has the conformal, low profile and 45 degree beam tilted configuration, and has the high gain with sharp beamwidth, low sidelobe and low loss is required for Ku-band satellite communication. In this paper, in order to meet with these performances, an array antenna consisting of the vertical polarized waveguide longitudinal slots based on the leaky-wave mode of traveling wave antenna is proposed. An array antenna consisting of 16 leaky-wave elements is showing 30 dBi of gain, 4.9 degree of beamwidth, below than -20 dB of sidelobe level, 45 degree of beam tilt angle in center frequency. Feed network designed by waveguide cooperated feed shows good performance of wideband and low loss.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.18-24
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• 2014

In this paper, the optimum placement of airborne line-of-sight (LOS) datalink directional antenna to minimize the datalink loss within the operation range of unmanned aerial vehicle (UAV) is analyzed by using the electromagnetic (EM) simulation. In quick banking of UAV, the datalink loss is occurred due to the electromagnetic distortion and transmission loss by the fuselage blockage. In general, the banking angle of UAV is limited to prevent the datalink loss. However, in this case, there is the problem that the mission performance ability is largely limited by the banking radius increase. To solve this problem, the optimum placement to mount the airborne LOS datalink 1-axis directional antenna on both the top and bottom surfaces of fuselage is analyzed by using EM simulation. The 1-axis antenna with large vertical beamwidth is used because the banking angle of UAV is dependent on the vertical beamwidth of antenna. Also, there is the benefit to reduce largely the weight because the 1-axis antenna can be mounted instead of the 2-axis one.

• The Journal of the Acoustical Society of Korea
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• v.23 no.8
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• pp.570-575
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• 2004

In the underwater acoustic systems. we can receive signals and retrieve information about a target by using a beamforming method. The most important thing in the beamforming is finding the way to optimize the mainlobe beamwidth and the sidelobe level to the desired value. One of the prominent results of beamforming method. which has been studied. is Philip's weighting function method(1) . Philip's method adaptively adjusts its weights of array to meet the desired mainlobe beamwidth and sidelobe level. It is very similar to the design method in adaptive filter. However. this method cannot easily bring us to the desired sidelobe level due to complementary relation between mainlobe beamwidth and sidelobe level. In this paper, we propose a new algorithm using partial constrained adaptation. This method makes us circumvent the above problem and meet the specification of design easily. The proposed algorithm presents a Pattern synthesis that designer can easily control the mainlobe beamwidth and the sidelobe level to the desired value while calculation time to converge is decreasing.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.5
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• pp.765-776
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• 2001

In this paper, a shaped offset gregorian antenna is electrically designed for Ku band FSS antennas of the domestic communications and broadcasting satellite which will be launched in the near future. For this, a design procedure for shaped offset gregorian antennas is described in detail, and a satellite antenna is designed by using the described design procedure. The radiation characteristics of the designed antenna are evaluated and compared with the design goals. The designed antenna is found to have 1.2$^{\circ}C$ beamwidth, 38.57 dBi EOC gain, and 43.19 dBi gain at Tx frequency 12.25 GHz and 1.08$^{\circ}$ beamwidth, 38.12 dBi EOC gain, and 44.11 dBi gain at Rx frequency 14.0 GHz. And also, side lobe levels and cross-polarization levels are less than -30 dB and -33 dB, respectively. From these results the designed antenna is found to be able to use for the domestic satellite FSS antennas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.125-129
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• 2010

This paper introduces an X-band microstrip patch array antenna that can be suitable for an energy saving system. The presented patch antenna comprises with 2-element linear array. The antenna is simulated using CST MWS and manufactured using FR-4(h=1.0mm, ${\varepsilon}r=4.4$). The estimated bandwidth, gain and beamwidth are 4%(VSWR$\leq$2), 6.3dBi and about 60o in elevation and 15o in azimuth, respectively. The antenna is fabricated and optimized based on the simulation result and installed on the backside of the sensor circuit and measured. The measured bandwidth, gain and beamwidth are 7%(VSWR$\leq$2), 4.8dBi and about 55o(El)/15o(Az), respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.5
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• pp.337-343
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• 2013

In this paper, IEEE 802.11 based WLAN(5.2/5.8GHz) wideband Weathercock-shaped microstrip patch antenna was designed and manufactured. The antenna has a size of $17.4{\times}17.4mm^2$ and utilized FR-4 board. The size was minimized for mobility, and Weathercock-shaped U-slot and short-pin was inserted to satisfy adequate bandwidth and double bandwidth resonance characteristics. In addition, the antenna incorporated single both-sided patch, and simulation design optimized the Weathercock-shaped, position of the U-slot and the short-pin, and the length of the patch for the measurement. The manufactured antenna achieved a bandwidth of 695MHz from 5.2~5.8GHz zone(Return loss<-10dB). Achieved a beam width of $81.13^{\circ}$ and $85.43^{\circ}$ for 3-dB beam width of H plane and E p;ane radiation pattern, there was 3.17~4.85dBi gain.