• Title, Summary, Keyword: Slot

Search Result 2,181, Processing Time 0.048 seconds

Design and Fabrication of the Hybrid Slot Antenna for Wireless LAN at 5.8㎓ Band (5.8㎓ 대역 무선 LAN용 하이브리드 슬롯 안테나 설계 및 제작)

  • 고수미;이권익;김흥수
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.39 no.10
    • /
    • pp.21-26
    • /
    • 2002
  • In this paper, a hybrid slot antenna is designed and fabricated for wireless LAN at 5.8㎓ band. The hybrid slot antenna is consisted of the inductively-fed slot and capacitively-fed slot. To obtain wide bandwidth, the inductively-fed slot is designed at 5.3㎓ and the capacitively-fed slot is designed at 5.8㎓ Important parameters in the design are slot width and CPW length. The hybrid slot antenna is simulated by using Ensemble 6.0. The measured results of this antenna are compared with its simulated results. The resonant frequency of fabricated hybrid slot antenna is 5.8㎓, the bandwidth for VSWR<1.5 is 28% and the gain is 5 ㏈i. The 3-㏈ beamwidths in E-plane and H-plane are 60°and 44°, respectively.

Study on Machine Characteristics in Interior Permanent Magnet Synchronous Motor According to Pole/Slot Combinations with Radial Vibration Force Consideration (극수/슬롯수 조합에 따른 Radial Vibration Force 고려한 매입자석 동기모터 특성 연구)

  • Fang, Liang;Lee, Su-Jin;Lee, Byeong-Hwa;Hong, Jung-Pyo
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.60 no.5
    • /
    • pp.949-954
    • /
    • 2011
  • This paper presents a comparative study on motor characteristics with specific consideration of radial vibration force in interior permanent magnet synchronous motors (IPMSM) according to pole/slot combinations. Three IPMSM models, 16-pole/15-slot design, 16-pole/18-slot design and 16-pole/24-slot design are built, in which 16-pole/15-slot and 16-pole/18-slot designs provide high winding factor and 16-pole/24-slot design is known as a general pole/slot combination. By coupling finite element analysis (FEA) with equivalent circuit method, motor characteristics, back electro-motive force (Back-EMF), inductances, cogging torque, etc. as well as machine output performances are analyzed and compared. The radial vibration force (RVF) distribution in air gap causing stator vibration and noise is interested. It is expected that this study help with appropriate choice of pole/slot combination in IPMSM design.

A Study on the Pressure Increase due to the Foam Left in the Radial Slot of Propellant Grain (추진제 그레인 래디얼 슬롯내의 폼 코어에 의한 압력증가 해석)

  • Kim Jong-Yul;Jung Gyoo-Dong;Yang Jun-Seo
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.7 no.4
    • /
    • pp.125-132
    • /
    • 2004
  • The radial slot configuration in the solid propellant grain is usually fabricated by the polyurethane foam slot former The foam cannot be easily removed from the solid propellant, some can remain in the slot. Analogue solid propellant rocket motors using polyurethane foam to shape the slot are static fired with the foam former still in place in the slot. The pressure increases at the slot part are measured and there are indications of the propellant cracks at the insulations above the slot. The pressure increase is produced at the beginning of the burning sequence as the foam will hinder the combustion gas of the burning propellant from flowing into the central bore. The pressure increase up to about 300psi is predicted for the motor tested and this pressure increase depends on the gap between the propellant and foam surfaces and remaining foam volume. This amount of pressure increase inside of the slot is estimated to cause the propellant crack. To prevent this pressure increase, minimizing the foam remainder in the slot and making sufficient chamfering at the comer of the slot entrance are suggested.

Compressive and Bending Behaviors of the Shielded Slot Plate Considering Forming Effect for Fuel Cell Application (성형 이력을 고려한 용융탄산염 연료전지용 쉴디드 슬롯 플레이트의 압축 및 굽힘 거동 분석)

  • Lee, C.W.;Yang, D.Y.;Kang, D.W.;Chang, I.G.;Lee, T.W.
    • Transactions of Materials Processing
    • /
    • v.21 no.6
    • /
    • pp.341-347
    • /
    • 2012
  • The metallic bipolar plates of the molten carbonate fuel cell(MCFC) are composed of shielded slot plates and a center-plate. The shielded slot plates support the center-plate and the membrane electrode assembly. Compressive forces are applied to the shielded slot plate in order to increase the contact area between shielded slot plates and the membrane electrode assembly (MEA). In the design of the shielded slot plate, it is necessary to predict the mechanical behavior of the shielded slot plate. The shielded slot plates are manufactured by a three-stage forming process consisting of slitting, preforming and the final forming process. The mechanical behavior of the shielded slot plate is largely affected by the forming process. In this study, the simulation of the three-stage forming process was used to predict the mechanical behavior of the shielded slot plate. The present simulation approach showed good agreements with the experimental results.

CFD based simulations of flutter characteristics of ideal thin plates with and without central slot

  • Zhu, Zhi-Wen;Chen, Zheng-Qing;Gu, Ming
    • Wind and Structures
    • /
    • v.12 no.1
    • /
    • pp.1-19
    • /
    • 2009
  • In this paper, the airflow around an ideal thin plate (hereafter referred to as ITP) with various ratios of central slot is simulated by using the finite-difference-method (FDM)-based Arbitrary-Lagrangian-Eulerian descriptions for the rigid oscillating body. The numerical procedure employs the second-order projection scheme to decouple the governing equations, and the multigrid algorithm with three levels to improve the computational efficiency in evaluating of the pressure equation. The present CFD method is validated through comparing the computed flutter derivatives of the ITP without slot to Theodorsen analytical solutions. Then, the unsteady aerodynamics of the ITP with and without central slot is investigated. It is found that even a smaller ratio of central slot of the ITP has notable effects on pressure distributions of the downstream section, and the pressure distributions on the downstream section will further be significantly affected by the slot ratio and the reduced wind speeds. Continuous increase of $A_2^*$ with the increase of central slot may be the key feature of the slotted ITP. Finally, flutter analyses based on the flutter derivatives of the slotted ITP are performed, and moreover, flutter instabilities of a scaled sectional model of a twin-deck bridge with various ratios of deck slot are investigated. The results confirm that the central slot is effective to improve bridge flutter stabilities, and that the flutter critical wind speeds increase with the increase of slot ratio.

The effective of Radiation Pattern on Two Shape of Slot Antenna

  • Chanwattanapong, W.;Anantrasirichai, N.;Wakabayachi, T.
    • 제어로봇시스템학회:학술대회논문집
    • /
    • /
    • pp.1660-1663
    • /
    • 2003
  • This paper present the characteristics of radiation pattern of microstrip slot antenna on the ground plane fed by microstrip line. It is proposed for resonance frequency at 10 GHz. We will analysis two shape of slot antenna; double L-shape slot antenna and U-shape slot antenna. In this case, we will compare far-field radiation pattern of two shape slot antenna. Far-field radiation pattern of double L-shape slot antenna is bi-directional nevertheless U-shape slot antenna is uni-directional. The microstrip slot antenna is propose to analyze far-field radiation pattern for use in the wireless communication systems

  • PDF

Ridge-Loaded Small Round-Ended Slot for Waveguide Slot-Array Antenna (도파관 슬롯 배열 안테나용 리지가 장하된 끝이 둥근 소형 슬롯)

  • Kim, Byung-Mun;Lee, Jong-Ig;Cho, Young-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.23 no.8
    • /
    • pp.950-957
    • /
    • 2012
  • In this paper, a small round-ended slot loaded by double ridges on the broad wall of a rectangular waveguide is presented as an element for a waveguide slot-array antenna(WSAA). By properly adjusting the ridge dimension, a resonance of the slot at a desired frequency can be achieved. The resonant length of the proposed slot is about $0.26{\lambda}_0$(free space wave length) at the resonance frequency. The proposed resonant slot has some advantageous properties, such as small size, small resonant conductance, and short and stable resonant slot length. In addition, the characteristics of the slots are slightly affected by the adjacent elements when the slots are arrayed for a waveguide slot antenna. A $4{\times}1$ WSAA with -20 dB side-lobe level(SLL) is designed, fabricated, and tested experimentally. The measured results are well agreed with the simulated ones and have an SLL of -15.9 dB and a half-power beam width of $110.2^{\circ}$ in the E-plane and $21.2^{\circ}$ in the H-plane, respectively, at 9.41 GHz.

Uniform Slot Width Bow-tie-shaped Meander Slot Antenna for 5 GHz Application (균일한 슬롯 폭을 갖는 5 GHz 대역 보우타이 형태의 미앤더 슬롯 안테나)

  • 위상혁;김정민;유태훈;육종관;박한규
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.13 no.8
    • /
    • pp.769-776
    • /
    • 2002
  • In this paper, we propose uniform slot width bow-tie-shaped meander slot antenna for 5 GHz application. The conventional bow-tie slot antenna has broadband characteristic, however, its size is large. Meanwhile, the meander slot antenna has small size, but it has quite narrow bandwidth. The proposed antenna geometry is a variation of the meander slot antenna incorporating bow-tie shape to realize miniaturized antenna having relatively large bandwidth. Simulated results show that with the same slot width and total slot length, the bandwidth of the proposed antenna is 3 times wider than that of meander slot antenna, and its resonant frequency is 3.01 GHz lower than that of the equal size(H x V) bow-tie slot antenna, and measured results show that the bandwidth of proposed antenna is 218 MHz(5.142 GHz ~ 5.360 GHz) which satisfy the required bandwidth from 5.15 GHz to 5.35 GHz.

Compact Dual-Band Half-Ring-Shaped Bent Slot Antenna for WLAN and WiMAX Applications

  • Yeo, Junho;Lee, Jong-Ig
    • Journal of information and communication convergence engineering
    • /
    • v.15 no.4
    • /
    • pp.199-204
    • /
    • 2017
  • A compact dual-band half-ring-shaped (HRS) bent slot antenna fed by a coplanar waveguide for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications is presented. The antenna consists of two HRS slots with different lengths and widths. The two HRS slots are connected through an arc-shaped slit, and the upper HRS slot is bent in order to reduce the size of the antenna. The optimized dual-band HRS bent slot antenna operating in the 2.45 GHz WLAN and 3.5 GHz WiMAX bands is fabricated on an FR4 substrate with dimensions of 30 mm by 30 mm. The slot length of the proposed dual-band slot antenna is reduced by 35%, compared to a conventional dual-band rectangular slot antenna. Experimental results show that the proposed antenna operates in the frequency bands of 2.40-2.49 GHz and 3.39-3.72 GHz for a voltage standing wave ratio of less than 2, and measured gain is larger than 1.4 dBi in the two bands.