A Systematic Design Method of On-Glass Antennas Using Mesh-Grid Structures

Seungbeom Ahn,Hosung Choo IEEE 2010 IEEE Transactions on Vehicular Technology VT Vol.59 No.7

<P>In this paper, we propose a systematic design method for an on-glass antenna, which is suitable for receiving frequency modulation (FM) radio in a commercial recreational vehicle (RV). For the main antenna body, we used a mesh-grid structure that most efficiently uses the given space of the glass for broad-matching bandwidth. To obtain the detail design parameters that exhibit optimum radiating performance, we used a genetic algorithm (GA) in conjunction with a full-wave electromagnetic (EM) simulator. To reduce the searching space in our GA process, we applied a connection-warranted filtering. After the GA optimization, we also applied a shape-simplification process and a transparency-improvement process to broaden the passenger's field of view. The designed antenna shows an average gain of about -9.05 dBi along the bore-sight direction (θ = 90°, Φ = 270°) in the FM radio band (80-120 MHz), which is 10 dB higher than a commercial roof-mounted microantenna. Finally, the operating principle of the proposed antenna was examined by using a lumped-element circuit model, and these results confirmed that the proposed antenna is well suited for FM radio reception in commercial RVs.</P>

Design of an on-glass vehicle antenna using a multiloop structure

Ahn, Seungbeom,Park, Seulgi,Noh, Yongho,Park, Dongwook,Choo, Hosung Wiley Subscription Services, Inc., A Wiley Company 2010 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.52 No.1

<P>We propose a novel on-glass antenna with a multiloop structure for FM radio reception in a recreational vehicle (RV). The proposed antenna consists of multiple loops that are printed on a quarter glass with copper striplines. In spite of its simple planar structure, the antenna provides a broad matching bandwidth and a high vertical radiation gain. Antenna performances such as the return loss and boresight gain were measured after the antenna was installed in a commercial RV. The proposed on-glass antenna exhibits an average gain of about −9.5 dBi with a deviation of <4 dB compared with the gain of a conventional λ/4 roof-mounted monopole. Transparency of the antenna body was also improved by adjusting the stripline widths based on the induced current distribution. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 107–110, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24836</P>

Diversity On-Glass Antennas for Maximized Channel Capacity for FM Radio Reception in Vehicles

Seungbeom Ahn,Yong Soo Cho,Hosung Choo IEEE 2011 IEEE transactions on antennas and propagation Vol.59 No.2

<P>This communication proposes a systematic design method to increase the diversity gain for vehicle on-glass antennas using the Pareto genetic algorithm. The initial antenna structure consists of two FM antennas printed on a rear window with horizontal conducting striplines. The position and the number of the vertical lines in the rear window were then determined using the Pareto genetic algorithm to maximize the channel capacity and average bore-sight gain of each antenna. The optimized antennas were built and mounted in a commercial sedan, and the antennas' performances, such as the reflection coefficient, radiation pattern, and channel capacity were measured. The measurements showed a matching bandwidth of around 15% and an average bore-sight gain of more than -12 dBi . The measured correlation coefficient of the two antennas was less than 0.6.</P>

FM 통신을 위한 인쇄형 컨포멀 안테나 설계

안승범(Seungbeom Ahn),김영기(Youggi Kim),강호원(Howon Kang) 한국항공우주학회 2018 한국항공우주학회 학술발표회 논문집 Vol.2018 No.4

다중 루프 형태의 차량용 글래스 안테나

안승범(Seungbeom Ahn),계영철(Youngchul Kay),추호성(Hosung Choo) 한국전자파학회 2009 한국전자파학회논문지 Vol.20 No.3

본 논문에서는 FM 라디오 수신을 위한 RV 차량용 글래스 안테나를 개발하였다. 형상이 간단하면서도 주어진 유리 면적을 효율적으로 이용하여 광대역 정합에 유리하고 높은 수직 편파 이득을 보이는 다중 루프 구조를 사용하였다. 또한, 상용 RV 차량에 장착 시 시야 확보 비율을 높이기 위해서 선로에 유기되는 전류 분포를 기반으로 선로 두께를 조절하여 안테나의 투명도를 향상시켰다. 제안된 안테나는 상용 RV 차량 쿼터 유리에 인쇄하였으며, 반사 손실과 이득 등의 안테나 성능을 반무반사실에서 측정하였다. 제안된 글래스 안테나는 FM 라디오 주파수 대역(80~110 ㎒)에서 안테나 전방향(bore-sight direction: θ=90°, φ=270°) 평균 이득이 -9.67 ㏈i로 상용 모노폴 글래스 안테나의 평균 이득 -12.49 ㏈i와 천장 부착용 마이크로 안테나의 평균 복사 이득 -19.24 ㏈i 보다 높은 이득을 보였다. In this paper, we propose a novel on-glass antenna for FM radio reception in a recreation vehicle(RV). We use a multi-loop structure that takes advantage of a broad matching bandwidth and a high vertical radiation gain by efficiently utilizing a given space of a quarter glass in spite of the simple planar structure. Transparency of the antenna is also improved by adjusting the stripline widths based on the induced current distributions. The proposed antenna is printed on a quarter glass of a commercial vehicle and antenna performances such as the return loss and the gain are measured in a semi-anechoic chamber. The result shows the average gain of -9.67 ㏈i along the bore-sight direction(θ=90°, φ=270°) in the FM radio band(80~110 ㎒), which is higher than a commercial monopole typed on-glass antenna(Gave=-12.49 ㏈i) and micro-antenna(Gave=-19.24 ㏈i) mounted on the roof of the RV.

FM 라디오 수신을 위한 차량용 다이버시티 안테나 설계

안승범(Seungbeom Ahn),노용호(Youngho Noh),오정훈(Junghoon Oh),추호성(Hosung Choo) 한국전자파학회 2009 한국전자파학회논문지 Vol.20 No.8

본 논문에서는 FM 라디오 수신을 위한 차량용 온-글래스 안테나 간의 채널 용량과 다이버시티 이득에 대하여 연구하였다. 안테나 간의 상관 계수 및 채널 용량은 도심 환경에 해당하는 Rayleigh 채널 환경과 안테나의 시뮬레이션 3차원 복사 패턴을 이용하여 계산하였다. 직선형 안테나와 L자형 안테나를 이용하여 채널 용량을 계산하였고 안테나의 급전 위치 및 L자형 안테나의 형상을 변화시켜 채널 용량 변화를 확인하였다. 실제 세단에 적용 가능한 급전 위치를 가지며 채널 용량이 높은 안테나 형상을 후면 글래스에 인쇄하여 야외 약전계 지역에서 FM 수신 출력을 측정하였으며, 안테나 수신 신호 간의 상관 계수는 0.65로 낮은 값을 보였다. 차량용 온-글래스 안테나에서 높은 다이버시티 이득을 얻기 위해서는 안테나 간의 급전 위치가 최대한 이격되어야 하며, 급전간 거리가 일정 이상 확보되었을 때에는 안테나의 편파가 달라야 함을 확인하였다. In this paper, we report on the channel capacity and diversity gain of the vehicle on-glass antenna for FM radio reception. The correlation coefficient and channel capacity were obtained using the simulated 3D radiation pattern of each antenna and the Rayleigh channel model for urban environment. To examine the channel capacity we used two antennas which are a simple straight antenna and L-type antenna. Then we observed the available channel capacity by varying the position of feeds and the shape of the L-type antenna. The sample antenna, which has a maximum feed distance with different polarizations, was built and the receiving performance was measured in the weak FM field area. From the results we confirmed that the distance between the feeds should be placed as far as possible for the high channel capacity. If the distance between the feeds are greater than a certain threshold value than the polarizations of the two antennas are getting more important for determining the channel capacity.

유리접지면 최적화를 통한 글래스 안테나의 성능 향상 기법

안승범(Seungbeom Ahn),한원근(Wone Keun Han),추호성(Hosung Choo) 한국전자파학회 2011 한국전자파학회논문지 Vol.22 No.2

본 논문에서는 차량 후면 유리에 여러 주파수 대역의 안테나를 집적화할 수 있는 유리접지를 이용한 안테나 급전 방법을 제안하였다. 유리접지가 가능하도록 동축 선로를 유리접지면에 직접 연결할 수 있는 어댑터를 설계 하였으며, 차체 접지 방식과 반사 손실을 비교 분석하였다. Azimuth 방향에서 높은 복사 이득을 얻기 위해 유리접지의 크기와 위치를 최적화 하였으며, 도출된 유리접지면을 이용하여 삼각 패치 형상의 WiBro 안테나를 상용 세단의 후면 유리에 인쇄하고 반사 손실과 복사 패턴 성능을 측정하였다. 제안된 유리접지를 이용한 급전 방식은 차체 접지를 이용한 급전 방식과 유사한 반사 손실을 보이며, 2 ㏈ 높은 azimuth 복사 이득이 나타내었다. 측정 결과, 제안된 유리접지면을 이용한 안테나 급전 방식을 이용하면 여러 주파수에서 동작하는 다양한 형태의 온-글래스 안테나를 후면 유리에 효과적으로 적용할 수 있음을 확인하였다. In this paper, we propose a novel feeding method that uses a windshield ground in a vehicle. The feeding method enables for various antennas to integrate easily in a vehicle windshield. To connect a coaxial feeding cable directly to the windshield ground, we inserted a coaxial-to-ground adapter between the cable and the ground, and reflection coefficients using the proposed feeding method were compared to that using a conventional feeding method. The size and position of the windshield ground were optimized in order to achieve a high radiation gain in the azimuth direction. Then the triangular WiBro patch antenna, incorporating the proposed feeding method, was designed and installed on a rear windshield of a commercial sedan. The antenna using the proposed feeding method shows a similar reflection coefficient, and it shows 2 ㏈ increased average azimuth radiation gain compared to that using a conventional sash ground method. These results demonstrate that the proposed feeding method can be applicable for integrating multiple antennas in a rear windshield.

Asymmetric Total Synthesis of (+)-Intricenyne via an Endocyclization Route to Oxocane Skeleton

Ahn, Jungmin,Lim, Changjin,Yun, Hwayoung,Kim, Hyun Su,Kwon, Soonbum,Lee, Jeeyeon,Lee, Seungbeom,An, Hongchan,Park, Hyeong-geun,Suh, Young-Ger American Chemical Society 2017 Organic letters Vol.19 No.24

<P>The first total synthesis of (+)-intricenyne consisting of an oxocane skeleton was achieved via an extremely selective endocyclization strategy. The key features of the synthesis include a regio- and diastereoselective epoxide opening reaction, concise elaboration of oxocane cores via abnormally selective endocyclization ether ring formation, and versatile incorporation of the labile functional groups.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2017/orlef7.2017.19.issue-24/acs.orglett.7b03370/production/images/medium/ol-2017-033705_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol7b03370'>ACS Electronic Supporting Info</A></P>

Lithofacies and U-Pb detrital zircon ages of the Jangsan and Myobong formations in the Sangguncheon section (Northeast Taebaeksan Basin): Preliminary report

Donghyeok Kang,Seungbeom Ahn,Jusun Woo 대한지질학회 2022 대한지질학회 학술대회 Vol.2022 No.10

Total synthesis of (+)-brasilenyne <i>via</i> concise construction of an oxonane framework containing a 1,3-<i>cis</i>,<i>cis</i>-diene

Lim, Changjin,Ahn, Jungmin,Sim, Jaehoon,Yun, Hwayoung,Hur, Joonseong,An, Hongchan,Jang, Jaebong,Lee, Seungbeom,Suh, Young-Ger The Royal Society of Chemistry 2018 Chemical communications Vol.54 No.5

<P>The enantioselective total synthesis of (+)-brasilenyne has been accomplished. The key features of the synthesis include the convergent preparation of a highly functionalized endocyclization precursor <I>via</I> selective epoxide opening, the construction of an oxonene skeleton through perfect regioselective Pd(0)-catalyzed endocyclization, and the installation of a 1,3-<I>cis</I>,<I>cis</I>-diene unit <I>via</I> a decarboxylative photophenylselenylation and site-selective selenoxide elimination sequence.</P>