• Advanced Composite Materials
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• 제17권3호
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• pp.215-224
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• 2008

The present study aims to design a multilayer microstrip antenna with composite sandwich construction and investigate fatigue behavior of this multilayer SAS (surface antenna structure) that was asymmetric sandwich structure for the next generation of structural surface technology. This term, SAS, indicates that the structural surface becomes an antenna. Constituent materials were selected considering electrical properties, dielectric constant and tangent loss as well as mechanical properties. For the antenna performance, antenna elements inserted into structural layers were designed for satellite communication at a resonant frequency of 12.2 GHz. From electrical measurements, it was shown that antenna performances were in good agreement with design requirements. In cyclic 4-point bending, flexure behavior was investigated by static and fatigue test. Fatigue life curve of the SAS was obtained. The experimental results of bending fatigue were compared with single load level fatigue life prediction equations and in good agreement. The SAS concept is can be extended to give a useful guide for manufacturers of structural body panels as well as antenna designers.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.55-58
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• 2005

The present study aims to design electrically and structurally effective antenna structures in order that the structural surface itself could become the antenna. The basic design concept is composite sandwich structure in which microstrip antenna is embedded and this is termed composite smart structure (CSS). The most important outstanding problem is that composite materials of structural function cannot be used without reducing antenna efficiency. Unfortunately, such materials have high electrical loss. This is a significant design problem that needs to be solved in practical applications. Therefore, the effects of composites facesheet on antenna performances are investigated in the first stage and changes in the gain of microstrip antenna due to composites facesheet have been determined. ‘Open condition’ is defined when gain is maximized and is a significant new concept for the design of high-gain antennas considering bandwidth in practical application. The open condition can be made with the outer facesheet by controlling its position. In the design of CSS, glass/epoxy composites and Nomex honeycomb were used with exploiting open condition. Experiments, confirm that the gain is improved and the bandwidth is also as wide as specified in our requirements. With the open condition, wideband antenna can be integrated with mechanical structures without reducing any electrical performances, as confirmed experimentally here.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.346-349
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• 2005

The present study aims to design electrically and structurally effective antenna structures in order that the structural surface itself could become the antenna. The basic design concept is composite sandwich structure in which microstrip antenna is embedded and this is termed composite smart structure (CSS). The most important outstanding problem is that composite materials of structural function cannot be used without reducing antenna efficiency. Unfortunately, such materials have high electrical loss. This is a significant design problem that needs to be solved in practical applications. Therefore, the effect of composites facesheet on antenna performances is studied in the first stage. Changes in the gain of microstrip antenna due to composites facesheet have been determined. 'Open condition' is defined when gain is maximized and is a significant new concept in the design of high-gain antennas considering bandwidth in practical application. The open condition can be made with any thickness of outer facesheet by controlling its position. In the design of CSS, glass/epoxy composites and Nomex honeycomb were used with exploiting open condition. Experiments, confirm that the gain is improved (over 11 dBi) and the bandwidth is also as wide as specified in our requirements (over 10% at 12.2 GHz). With the open condition, wideband antenna can be integrated with mechanical structures without reducing any electrical performances, as confirmed experimentally here.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.142-147
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• 2023

This paper presents a novel design of a differential patch antenna for 60-GHz millimeter-wave applications. The design process of the back-to-back (BTB) patch antenna is based on the conventional single-patch antenna. The initial design of the BTB patch antenna (Type-I) has a patch size of 0.66 × 0.98 mm² and a substrate size of 0.99 × 1.48 mm². It has a gain of 1.83 dBi and an efficiency of 94.4% with an omni-directional radiation pattern. A 0.4 mm-thick high-resistivity silicon (HRS) is employed for the substrate of the BTB patch antenna. The proposed antenna is further analyzed to investigate the effect of substrate size and resistivity. As the substrate resistivity decreases, the gain and efficiency degrade due to the substrate loss. As the substrate (HRS) size decreases approaching the patch size, the resonant frequency increases with a higher gain and efficiency. The BTB patch antenna has optimal performances when the substrate size matches the patch size on the HRS substrate (Type-II). The antenna is redesigned to have a patch size of 0.81 × 1.18 mm² on the HRS substrate in the same size. It has an efficiency of 94.9% and a gain of 1.97 dBi at the resonant frequency of 60 GHz with an omni-directional radiation pattern. Compared to the initial design of the BTB patch antenna (Type-I), the optimal BTB patch antenna (Type-II) has a slightly higher efficiency and gain with a considerable reduction in antenna area by 34.8%.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.316-320
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• 2004

This paper describes Ka-band antenna performance analysis of COMS satellite. The key parameters of the antenna system are optimal antenna diameter, feed horn type and horn size, F/D, and the coordinate of offset horns. The paper deals with the method to determine design core parameters of optimal antenna diameter, feed horn type and horn size, F/D, and the coordinate of offset horns, and the performances of design result.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.195-198
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• 2002

Two types of conformal load-bearing antenna structure (CLAS) were designed with microwave composite laminates and Nomex honeycomb cores, to give both structural rigidity and good electrical performance. One is 4$\times$8 array for Synthetic Aperture Radar(SAR) system and the other is $5\times2$ array for wireless LAN system. Design was based on wide bandwidth, high polarization purity, low loss and good structural rigidity. We studied the design, fabrication and structural/electrical performances of the antenna structures. The flexural behavior was observed under a 3-point bending test, an impact test, and a buckling test. Electrical measurements were in good agreement with simulation results and these complex antenna structures have good flexural characteristics. The design of this antenna structure is extended to give a useful guide for sandwich panel manufacturers as well as antenna designers.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2019-2024
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• 2014

This paper presents a method to optimize the design of a planar-type antenna and reduce the number of design parameters for rapid computation. The electromagnetic characteristics of the structure are analyzed, and Taguchi method is used to identify critical design parameters. Adaptive particle swarm optimization, which has a faster convergence rate than particle swarm optimization, is used to achieve the design goal effectively. A compact dual-band USB dongle antenna is tested to verify the advantage of the proposed method. In this case, we can use only five selected geometrical parameters instead of eighteen to accelerate the optimization of the antenna design. The 10 dB bandwidth for return loss ranges from 2.3 GHz to 2.7 GHz and from 5.1 GHz to 5.9 GHz, covering all the WiBro, Bluetooth, WiMAX, and 802.11 b/g/n WLAN bands in both simulation and measurement. The optimization process enables the antenna design to achieve the required performance with fewer design parameters.

• Journal of electromagnetic engineering and science
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• 제10권3호
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• pp.79-85
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• 2010

In this paper, a directive antenna design with a combination of electric-magnetic radiators for an radio frequency identification(RFID) system is presented. To generate a directive antenna radiation pattern, a structure combining a dipole and loop antenna is presented. A reader antenna and tag antenna are proposed for the RFID system. For the reader antenna, the frequency bandwidth defined by $S_{11}$<-10 dB is approximately from 820~990 MHz. The forward and backward gain differences are 1.5~2 dBi. For the tag antenna, the frequency bandwidth is approximately from 860~920 MHz with a maximum gain of 3.58 dBi at 910 MHz. In both cases, directive radiation characteristics are observed.

• 반도체디스플레이기술학회지
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• 제17권2호
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• pp.20-25
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• 2018

In this paper, we have designed circularly polarized array antenna for 5.8GHz microwave wireless power transmission. To obtain high antenna gain, we studied a single patch antenna, a $2{\times}1$ array antenna, a $2{\times}2$ array antenna, a $2{\times}4$ array antenna, and a $4{\times}4$ array antenna. Commonly, characteristics of each antenna have a frequency of 5.8 GHz and Right Hand Circular Polarization(RHCP) of circular polarization. Also, the results were obtained with the design to each antenna that the return loss was less than -10dB and the axial ratio was less than 3dB. The gain of the antennas was 6.08dBi for a single patch antenna, 9.69dBi for a $2{\times}1$ array antenna, 12.99dBi for a $2{\times}2$ array antenna, 15.72dBi for a $2{\times}4$ array antenna and 18.39dBi for a $4{\times}4$ array antenna. When the elements of the array antenna were increased, it was confirmed that it increased by about 3dBi.

• 한국위성정보통신학회논문지
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• 제12권1호
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• pp.72-75
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• 2017

본 논문은 소형화와 고이득을 위하여 패치 안테나에 원형 슬릿을 구현하였으며 900 MHz 대역에서 동작이 되도록 설계하였다. 사각형 모양의 패치형태를 변형하여 안테나 크기를 일차적으로 줄였으며 나아가 패치 안에 원형 슬릿을 추가하여 추가적으로 안테나의 크기를 감소시켰다. 원형슬릿의 개수와 반지름을 설계 변수로 설정하여 원하는 대역에서 반사손실을 약 -30 dB까지 되도록 Tuning 하였으며 방사패턴의 최대 이득도 약 4 dBi에 이르도록 안테나의 설계를 수행하였다. 원형슬릿이 존재하지 않는 경우 대비 약 20 MHz 정도의 공진 주파수 하향천이를 구현하여 본 논문에서 설계한 안테나의 소형화가 달성되었음을 증명하였다.