• Title, Summary, Keyword: U-Slot

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Design and Fabrication of Mulitiple U-shaped slot Microstrip Antenna on 5㎓ Application (5㎓ 대역에서 동작하는 다중 U-슬롯 모양의 마이크로스트립 안테나의 설계 및 제작)

  • 윤중한;정계택;이상목;안규철;곽경섭
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.11
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    • pp.85-92
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    • 2003
  • In this paper, a multiple U-shaped slot antenna on 5㎓ band is designed, fabricated, and measured. The prototype consists of a U-shaped slot and two Invert U-shaped slot. To obtain wide bandwidth, the foam layer is inserted between ground plane and substrate. After various parameters, length, width, position of U-shaped slot horizontal, interval length between two invert U-shaped slot, feeding position and airgap width, optimized, a multiple U-shaped slot antenna is fabricated and measured. The measured results of the antenna are compared with its simulated results. A 2:1 VSWR impedance bandwidth of 20.4% is achiedved by employing this technique. The gain is about 5.5㏈i. The experimental far-field patterns are stable across the pass band.

Geometric Effects of Compartment Opening on Fuel-Air Mixing and Backdraft Behavior (개구부의 기하학적 형상이 구획실의 연료-공기 혼합특성 및 백드래프트 거동에 미치는 영향)

  • Ha, Suim;Oh, Chang Bo
    • Fire Science and Engineering
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    • v.33 no.1
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    • pp.30-38
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    • 2019
  • Mixing characteristics and backdraft dynamics were investigated using large eddy simulation for compartments initially filled with methane fuel. Four different opening geometries, i.e. conventional door opening case (Door) and the cases where horizontal door was implemented on the upper ($Slot_U$), middle ($Slot_M$) and lower part ($Slot_L$) of side wall, were considered in the simulations. For cases without ignition, the amounts of inflow oxygen and outflow fuel from the compartment opening were, from largest to smallest, Door > $Slot_U$ ~ $Slot_M$ > $Slot_L$. However, the fuel and oxygen were the best mixed for the $Slot_U$ case while the fuel and oxygen were not well mixed and in relatively separated two layers for the $Slot_L$ case. The global equivalence ratio defined by the amounts of fuel and oxygen in the compartment was not correlated reasonably with the peak pressure of backdraft. The peak pressure during backdraft was the highest for the $Slot_U$ case, a well mixed condition of fuel and air, and backdraft was not found for the $Slot_L$ where the pressure rise was not so high due to the mixing status. The peak pressures for the Door and $Slot_M$ cases were in between Door and $Slot_L$ cases. The peak pressure during backdraft was well correlated with the total amount of heat release until the instance of backdraft occurrence.

A 28-GHz Wideband 2×2 U-Slot Patch Array Antenna

  • Yoon, Nanae;Seo, Chulhun
    • Journal of electromagnetic engineering and science
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    • v.17 no.3
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    • pp.133-137
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    • 2017
  • In this study, a 28-GHz U-slot array antenna for a wideband communication system is proposed. The U-slot patch antenna structure consists of a patch, two U-shaped slot, and a ground plane. With the additional U-slot, the proposed antenna has around 10% of bandwidth at -10 dB. To increase gain, the U-slot antenna is arrayed to $2{\times}2$. The proposed antenna is designed and fabricated. The $2{\times}2$ array antenna volume is $41.3mm{\times}46mm{\times}0.508mm$. The proposed antenna was measured and compared with the simulation results to prove the reliability of the design. The bandwidth and gain of the measurement results are 3.35 GHz and 13 dBi, respectively and the operating frequency is around 28 GHz.

Design of U-slot Array for OCS Base Station (PCS 기지국용 U-슬롯 어레이 안테나 설계)

    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.1
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    • pp.117-124
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    • 2001
  • In this paper, the design of a U-slot array antenna for PCS base station has been implemented and studied. The U-slot antenna is a single layer type with an antenna volume smaller but a bandwidth lager than the designs utilizing parasitic patches, which exceed 17 % bandwidth, for the probe fed case. Designed U-slot array antenna has stable radiation patterns and an average gain above 12 dB across the PCS frequency band. In this paper, through the designing of a U-slot array antenna, we have presented the availability for PCS base station antenna.

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The effective of Radiation Pattern on Two Shape of Slot Antenna

  • Chanwattanapong, W.;Anantrasirichai, N.;Wakabayachi, T.
    • 제어로봇시스템학회:학술대회논문집
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    • pp.1660-1663
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    • 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

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Design and Fabrication of Multiple U-shaped slot Microstrip Antenna for 5.25GHZ Band Wireless LAN (5-25GHZ 대역 무선 LAN 다중 U 슬롯 모양의 마이크로스트립 안테나 설계 및 제작)

  • 윤중한;정계택;최현규;곽경섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.6A
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    • pp.414-424
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    • 2003
  • In this paper, a multiple U-shaped slot antenna for 5.25㎓~5.35㎓ is designed, fabricated, and measured. The prototype consists of U-slot and two invert U-slot. To obtain enough bandwidth, the foam layer is inserted between ground plane and substrate. Important parameters in the design are U-slot length, width, position, airgap length, and feed point. From these parameters optimized, a multiple U-shaped slot antenna is fabricated and measured. The measured results of the antenna are compared with its simulated results. The resonant frequency of the fabricated multiple U-shaped slot antenna is 5.25㎓ the bandwidth for approximately 7.4%(VSWR<1.5) and the gain is 2.9~5.3dBi. The experimental far-field patterns are stable across the pass band. The 3dB bandwidth in H-Plane and I-Plane are 62$^{\circ}$ and 50$^{\circ}$, respectively.

Design of a Pot-Shaped Monopole Antenna with Dual Band Notched Characteristics for UWB Application

  • Mok, Kwang Yun;Rhee, Young Chul;Yoon, Joong Han
    • Journal of electromagnetic engineering and science
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    • v.17 no.1
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    • pp.44-49
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    • 2017
  • A compact planar microstrip-fed ultra-wideband (UWB) antenna with a dual band-notched for UWB application is presented and analyzed. By inserting a U-shaped slot and inverted U-shaped slot into the pot-shaped radiator, two notched bands are achieved. By optimizing the width and length of the U-shaped slots and inverted U-shaped slot, a desired bandwidth of voltage standing wave ratio (VSWR) less than 2.0 can be achieved, ranging from UWB bands with notched dual bands. The proposed antenna is fabricated on an inexpensive FR-4 substrate with overall dimensions of $28.0mm{\times}39.5mm$. The measured results confirm that the proposed antenna covers from 1.775 to over 13.075 GHz with two rejection bands of around 3.325-3.925 GHz and 5.3125-6.025 GHz. In addition, the proposed antenna showed good radiation characteristics and gains in the UWB bands.

A Study on the Design of Wideband Antenn as using U-Slot Patches (U-Slot 패치를 이용한 광대역 안테나의 설계에 관한 연구)

  • Kim Won-Bae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.3
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    • pp.180-185
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    • 2005
  • Microstrip antennas generally have a lot of advantages that are thin profile, lightweight, low cost, and conformability to a shaped surface application with integrated circuitry. In addition to military applications, they have become attractive candidates in a variety of commercial applications such as mobile satellite communications, the direct broadcast system (DBS), global positioning system (GPS), and remote sensing. Recently, many of the researches have been achieved for improving the impedance bandwidth of microstrip antennas. The basic form of the microstrip antenna, consisting of a conducting patch printed on a grounded substrate, has an impedance bandwidth of $1\~2\%$. For improvement of narrow bandwidth of microstrip patch, we were designed U-slot microstrip patch antenna in this paper. This antenna had wide bandwidth for all personal communication services (PCS) and IMT-2000. For the design of U-slot microstrip patch antenna using a finite difference time domain(FDTD) method. This numerical method could get the frequency property of U-slot patch antenna and the electromagnetic fields of slots.

Design of Wide Band U-slot Patch Antennas for Mobile Communications (이동통신용 광대역 U-슬롯 패치 안테나 설계)

  • 전주성
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.6
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    • pp.882-889
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    • 2001
  • In this paper, the characteristics of u-slot antennas are computed by changing the feed structure, and compared with the measured results. The impedance bandwidths of 13 %(255.1 MHz) and 30.7 %(602.1 MHz) are obtained for probe feed and L-strip feed, respectively. It is known that the designed L-strip feed can be used for increasing the bandwidth of u-slot antennas. In addition, it is shown that the designed L-strip feed u-slot antenna can be used for domestic PCS and IMT-2000 dual band applications.

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A Study on Aperture Coupled U-slot Microstrip Antenna using Wideband Stub (광대역 Stub를 이용한 개구 결합 급전 방식의 U 슬롯 마이크로스트립 안테나에 관한 연구)

  • 김현준;윤영중
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.4
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    • pp.342-350
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    • 2002
  • In this paper, aperture coupled U-slot microstrip antenna with wideband stub is investigated. The dielectric constant of the substrate is 2.2 and the hight of the substrate is 62 mil. The impedance bandwidth (VSWR<1.5) of U-slot antenna with wideband stub is about 10 %. The bandwidth characteristic of U-slot antenna wish wideband stub is compared with that of antenna without it. And the results of parameter studies of the wideband stub provides the optimum characteristics of bandwidth and matching.