• Title/Summary/Keyword: Waveguide

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Slotted Waveguide Array Antenna using Dumbbell Patch for Millimeter-Wave (Dumbbell 패치를 이용한 밀리미터파 대역 슬롯 도파관 안테나)

  • 이정수;성영제;김영식
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.4
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    • pp.353-359
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    • 2004
  • In this paper, the single-layer slotted waveguide array antenna is designed, which consists of two par the slot plate and the structure of waveguide. The key difficulty in mass production is the realization of perfect electrical contact between the two parts. Therefore the single-layer slotted waveguide array antenna is presented with a dumbbell patch and a choke. The choke can prevent from the leakage between the slot plate and waveguide, while the choke in the adjacent waveguide incurs space dissipation. To reduce the spacing of antennas about a dumbbell patch is utilized. the 16${\times}$16 array antenna gain of 27.2 ㏈ with 45 % aperture efficiency is obtained.

A Planar Waveguide Model for Calculating Microstrip Dispersion Characteristics (마이크로 스트립 선로의 분산특성 계산을 위한 Planar Waveguide 모델)

  • 유희준;고성선;윤현보
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.10 no.6
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    • pp.335-342
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    • 1985
  • A planar waveguide model is presented for calculating dispersion characteristics with the frequency dependent effective dielectric constant in microstrip lines and results are compared by the variation of each parameter. It is compared to use a wide range of relative dielectric constants and the strip $h_{width}$strate height, W/h ratios, 0.9$\leq$W/h$\leq$2. As the result of a computer simulation, the normalized phase velocity using a planar waveguide model for each case is more closely approached to 1/$\sqrt{\epsilon_r}$ as the increasing of the frequency than the other method that has already been presented.

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Design of a Ka-Band Orthomode Transducer (Ka-대역 직교모드변환기 설계)

  • 이종경;채범용;박동희;안병철
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.1
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    • pp.110-118
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    • 2004
  • In this paper, a method is presented for the design of an orthomode transducer(OMT) operating at 21/31GHz frequency bands. A square waveguide is used in the common port while the WR-34 standard rectangular waveguide is used in the straight port. The straight port is connected to the common port via a multi-stage quarter-wave impedance transformer. The side port is coupled to the common port through a slot formed along the center line of the common square waveguide. An impedance transformer is employed to match the impedance of the coupling slot with that of the WR-51 waveguide at the output of the side port. Dimensions of the OMT are iteratively optimized employing the theory of waveguide. The validity of the proposed method is verified by fabricating and testing the designed orthomode transducer.

Design of a Compact Coaxial Waveguide Feed Horn for Dual Band (이중 대역 소형 동축 도파관 급전 혼 설계)

  • Yun, Sohyeun;Uhm, Manseok;Yom, Inbok
    • Journal of Satellite, Information and Communications
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    • v.10 no.3
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    • pp.109-113
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    • 2015
  • This paper presents the study results on a dual band feed horn for the focused reflector. A coaxial waveguide structure is attractive to avoid blockage from the feeder. The inner conductor as a hollow waveguide is designed to excite TE11 of a circular waveguide for high frequency. For low frequency, the design of the outer coaxial waveguide that propagates coaxial TE11 and prevents fundamental TEM is presented. The horn size for generation of these modes results in the degradation of performance. The return loss is improved by a capacitive iris and an inductive iris The enhanced pattern symmetry by dual mode is presented. The horn design in this paper are verified through the test.

Design of Mode Transducer between $TE_{10}$ Mode in Rectangular Waveguide and $TE_{11}$ Mode in Circular Waveguide (구형 도파관 $TE_{10}$모드와 원형 도파관 $TE_{11}$모드간의 모드변환기 설계)

  • Doo-Yeong Yang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.7 no.3
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    • pp.246-253
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    • 1996
  • In this paper, a problem that occurred in the telegraphist equation established by mode conversion method is solved as analysis tapered transmission line is applied to a waveguide taper. After comparing and analyzing the taper function with variant properties, we select on of taper functions not only that is easily designed but also that have good properties. And then we propose the applicant method to design the waveguide taper and deal with the design of mode transducer between rectangular waveguide and circular waveguide. The measured results of scattering coefficients for the mode transducer fabricated with designed data are agreed well with the theoretical results and the validity of the proposed design and analysis method has been confirmed.

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Development of Optimal Design User Interface for Waveguide tee Junction using PSO Algorithm and VBA (PSO 알고리즘과 VBA를 이용한 Waveguide tee Junction의 최적설계 인터페이스 개발)

  • Park, Hyun-Soo;Byun, Jin-Kyu;Lee, Dal-Ho;Lee, Hyang-Beom
    • 한국정보통신설비학회:학술대회논문집
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    • pp.36-39
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    • 2009
  • We developed an optimal design interface based on VBA(Visual Basic Application) that takes advantage of API(Application Program Interface) function of commonly used EM analysis software. The developed interface is adopted for an optimal design of a septum in a waveguide tee junction using PSO(Particle Swarm Optimization) algorithm. The objective function of the optimal design is defined by $S_{11}$-parameter of the waveguide tee junction Design variables are established as position of the septum, that are changed to satisfy the design goal Using the developed design interface and PSO algorithm, the objective function converged to the smallest value, showing the validity of the proposed method. The design interface was developed using Microsoft Excel software, enabling easy control of design parameters for user. Also, various analysis parameters can be set in the Excel interface, including waveguide input mode and frequency. After completion of the design, field solutions at user-specified positrons can be extracted to the output files in complex number form.

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A Coaxial Waveguide-based Spatial Combiner Using Finline-to-Microstrip Transitions (핀라인-마이크로스트립 변환을 이용한 동축선로 도파관 형태의 공간 결합기)

  • Kim, Bo-Ki;Lee, Su-Hyun;Kim, Hyoung-Jong;Shin, Suk-Woo;Kim, Sang-Hoon;Kim, Jae-Duk;Choi, Jin-Joo;Kim, Seon-Joo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.5
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    • pp.79-86
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    • 2011
  • In this paper, a S-band coaxial waveguide-based spatial combiner is proposed. The proposed combiner consists of coaxial waveguide, impedance transformer, and finline-to-microstrip transformer. The coaxial waveguide is used as the host of the combining circuits for higher output power and better uniformity by equally distributing the input power to each element. The finline-to-microstrip transformer is designed by using antipodal antenna, and obtained low reflection coefficient by applying the small reflection theorem. The measurement results show the coaxial waveguide combiner has a maximum combining efficiency of 95%.

Layered-Type Dielectric Waveguide Filter Using Ceramic (세라믹을 이용한 적층형 유전체 도파관 필터)

  • Jang, Young-Soo;Kim, Jong-Chel;Kim, Seung-Wan;Lee, Kie-Jin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.2
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    • pp.122-127
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    • 2013
  • Layered-type dielectric waveguide filters were designed. As the order of layers increased the fabrication process for dielectric waveguide filters which the resonator parts were connected by the lateral direction has many difficulties. The proposed structure in this report was designed based on the layered-type for the some parts of resonators. The size of layered-type dielectric waveguide filters installed on the PCB surface were reduced at 25% as compared with the usual waveguide filters by using a relative dielectric constant 22.

Consistent Boundary Condition for Horizontally-Polarized Shear (SH) Waves Propagated in Layered Waveguides (층상 waveguide에서의 SH파 전파 해석을 위한 경계조건)

  • Lee, Jin Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.2
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    • pp.113-120
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    • 2021
  • The wave-propagation phenomenon in an infinite medium has been used to describe the physics in many fields of engineering and natural science. Analytical or numerical methods have been developed to obtain solutions to problems related to the wave-propagation phenomenon. Energy radiation into infinite regions must be accurately considered for accurate solutions to these problems; hence, various numerical and mechanical models as well as boundary conditions have been developed. This paper proposes a new boundary condition that can be applied to scalar-wave or horizontally-polarized shear-wave (or SH-wave) propagation problems in layered waveguides. A governing equation is obtained for the SH waves by applying finite-element discretization in the vertical direction of the waveguide and subsequently modified to derive the boundary condition for the infinite region of the waveguide. Using the orthogonality of the eigenmodes for the SH waves in a layered waveguide, the new boundary condition is shown to be equivalent to the existing root-finding absorbing boundary condition; further, the accuracy is shown to increase with the degree of the new boundary condition, and its stability can be proven. The accuracy and stability are then demonstrated by applying the proposed boundary condition to wave-propagation problems in layered waveguides.

16-port Feed Waveguide Array for DBS Reception System Mounted on Vehicle (차량 탑재형 DBS 수신 시스템용 16 포트 급전 도파관 어레이)

  • Min, Gyeong-Sik;Kim, Dong-Cheol
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.2
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    • pp.92-100
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    • 2002
  • The 16-port feed waveguide array with inductive walls analyzed by Galerkin's method of moments are proposed for the DBS reception system mounted on vehicle. First of all, in order to verify the validity of electromagnetic analysis and design for a $\pi$-junction feed waveguide, it is designed and fabricated at DBS band. The measurement results of a $\pi$-junction feed waveguide agree well with the theoretical ones. Based on this design method, an array design for WR-90 standard waveguide is conducted. Since the width of a $\pi$-junction feed WR-90 standard waveguide is larger than a guided wave length in an array design, the difference of amplitude and phase of 8-port array are calculated 2.3 dB and 62 degrees, respectively. The bandwidth with return loss of -20 dB below is about 220 MHz and it doesn't satisfy DBS band. To solve this problem, we propose a novel design that the width of a $\pi$-junction feed waveguide equals to a guided wave length. By the proposed novel design for 8-port feed waveguide array, the difference of amplitude and phase are decreased 1 dB and 13 degrees, respectively. The broad bandwidth of 700 MHz is also realized. The size of 16-port waveguide away compared with WR-90 array is reduced about 10 cm. The measured antenna gain for the fabricated 16-port feed waveguide array is observed 24 dBi above at DBS band.