• Title/Summary/Keyword: 동축선로 임피던스 변환기

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The fabrication of a coaxial line impedance transformer with low transmission loss and wideband operation range (저손실 광대역 동작 특성을 가지는 동축 선로 임피던스 변환기 제작)

  • Park, Ung-hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.12
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    • pp.2241-2248
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    • 2017
  • The coaxial line impedance transformer that performs impedance conversion using the coupling of two or more coaxial lines of the same length is often used for impedance matching in the low frequency region due to many advantages. This paper measures the phase and magnitude characteristics of each coaxial line in a 4:1 coaxial line impedance transformer using two 100mm coaxial lines. This experiment shows that it is more effective to make the length of the auxiliary coaxial line shorter than the main coaxial line by about 5 mm in order to realize a low loss impedance transformer. In addition, it measures the transmission characteristics by directly connecting a 4:1 impedance transformer and a 1:4 impedance transformer. This experiment shows that it is effective to connect a 1pF capacitor between the ground and the outer conductor input point of the main coaxial line in order to increase the operating frequency range.

The analysis of the operating characteristic for the wideband coaxial line impedance transformer (광대역 동축선로 임피던스 변환회로의 동작 특성 분석)

  • Park, Ung-hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.2
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    • pp.165-172
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    • 2019
  • Using two or more coaxial lines, if one port is connected in series and the other port is connected in parallel, it can be implemented the wideband transmission line transformer(TLT). Because the wideband TLT utilizes the outer conductor of the coaxial line, it is difficult to predict the characteristics. In this paper, based on the analysis for the transfer characteristic(S21) according to the loss of the each line in ${\lambda}/4$-microstrip line TLT, the operating characteristic of the fabricated wideband 4:1 TLT using two $25{\Omega}$-coaxial lines is investigated. The fabricated wideband TLT shows the notch characteristic in which the transfer signal sharply decreases at ${\lambda}/4$ frequency of the coaxial line and has a value within -0.2dB of the transfer characteristic(S21) in $0.06{\sim}0.2{\lambda}$ frequency range of the coaxial line. This transfer characteristics(S21) can change the operating frequency range slightly and set the optimum transfer characteristic(S21) at the desired frequency by changing the length of the microstrip line.

Wideband Power Divider Using a Coaxial Cable (동축선을 이용한 광대역 전력 분배기)

  • Park, Ung-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.4
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    • pp.661-668
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    • 2012
  • A coaxial-cable impedance transformer that can be used in high power and wideband frequency range is an arbitrary impedance transformation ratio by an additional coaxial cable. The coaxial-cable impedance transformer to be 50-${\Omega}$ to 25-${\Omega}$ impedance transformation ratio is easily operated an wideband power divider by connecting two 50-${\Omega}$ lines at 25-${\Omega}$ impedance point. This wideband power divider has a poor output matching characteristic and a poor isolation characteristic between two output ports. In this paper, it proposes a coaxial-cable power divider to be a good output matching and isolation characteristics as it uses the singly terminated filter design theory. The odd-mode operation characteristic of the suggested power divider to use singly terminated low pass filter coefficient due to matching order and ripple value is examined by ADS program. And, it fabricates and measures the operation characteristic of 2-way power divider with 2nd-order and 4th-order matching circuit.

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%.

Wideband 6-port Phase Correlator Using Caxial Cable Impedance Transformer and Wireline Coupler (동축선 임피던스 변환기와 Wireline Coupler를 이용한 광대역 6-단자 위상 상관기)

  • Park, Ung-hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.8
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    • pp.1188-1195
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    • 2022
  • The 6-port phase correlator consists of one in-phase power divider and three 3-dB 90-degree phase difference power dividers, and is mainly used in a demodulation circuit that determines the phase of an input signal. This paper proposes the wideband 6-port phase correlator that consists of an in-phase power divider using a wideband 2:1 impedance transformer with three 37.5-Ω coaxial cables, and a 3-dB 90-degree phase difference power divide using Wireline. The proposed wideband phase correlator fabricated at a center frequency of 1000MHz has the value of the input reflection coefficient(S11 and S22) -14dB or less in the frequency range of 640~1270MHz. Also, the signal transmission characteristic(Si1), from the in-phase power divider input port to four output ports, has the amplitude of -6.5±0.6dB and the phase error of within ±3.4°, and the signal transmission characteristic(Si2), from the 90 degree phase difference power divider input port to four output ports, has the amplitude of -6.1±0.6dB and the phase error of within ±6.2°.

Design and fabrication of rectangular waveguide-to-microstrip transition at Ka-band (Ka-band에서의 구형 도파관-마이크로스트립 변환구조의 설계 및 제작에 관한 연구)

  • 정진호;권영우;장영춘;천창율
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.7
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    • pp.1770-1776
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    • 1998
  • This paper presents a waveguide-to-mircostrip transition at Ka-band using antipodal finlines. Critical design parameters were identified with the help of theoretical analysis. Experimental optimization was performed together with 3-D FEM analysis in an effort to find optimum dimensions of the transition. In addition to the conventional antipodal finline transition, a new dielectric impedance transformer was introduced to further reduce the insertion loss. Optimized waveguide-to-microstrip transition showed an insertion loss of 0.3~0.4dB/transition at Ka-band. This transition provides superior reproducibility and better performance than conventional coaxcable-to-microstrip transition.

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Wideband horn antenna including circular-polarizer and straight-type mode-converter for Ka-band (Ka-대역 원형 편파기와 직선구조 모드 변환기를 포함한 광대역 혼 안테나)

  • Jung, Young-Bae
    • Journal of IKEEE
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    • v.15 no.4
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    • pp.299-304
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    • 2011
  • In this paper, the circular polarized horn antenna composed of circular polarizer and impedance transformer is designed, and fabricated. For the circular polarizer, two types of the polarizer are designed and the electrical performance of them is compared; rectangular waveguide polarizer with $45^{\circ}$-inclined dielectric slab and oval shaped one. Straight type mode converter has a stepped impedance structure and plays a role of converting waveguide TE mode into coaxial TEM mode, and the proposed antenna is designed to directly connect with active components using the feed-through in the input port of the mode converter. Fabricated antenna has the wideband performance, VSWR<1.5 and Axial ratio < 1.0dB, ranging from 30.085 to 30.885 GHz, and the antenna gain is 6.7~7.0 dBi.

A Stripline 10-Way Power Divider for the Feed Network of an S-band Linear Array Antenna (S-대역 선형 배열 안테나의 급전 회로를 위한 스트립라인 10-출력 전력분배기)

  • Park, Il-Ho;Kim, Rak-Young;Park, Jung-Yong;Jeong, Myung-Deuk;Kim, Dong-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.3
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    • pp.280-288
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    • 2009
  • In this paper, a high-power and low-loss stripline 10-way power divider is designed and fabricated fur the feed network of an S-band linear array antenna with Chebyshev current distribution which has a narrow beam width and low side lobe level(SLL) of 35 dB or more. The unit cell of the power divider is based on a T-junction power divider and the whole divider is comprised of the cascaded unit cells. The multi-stage impedance transformer and modified ring hybrid are used in designing the power divider for performance improvement. And the reflection loss and insertion loss are improved by modifying a connector structure for a coaxial-to-stripline transition.

Modeling of a Thermal Voltage Converter and Development of AC-DC Transfer Difference Calculation Program (열전형 전압변환기의 모델링 및 교류-직류 변환 차이 계산 프로그램 개발)

  • Lee Jung-Nam;Kwon Sung-Won;Jung Jae-Kap;Lee Hyo-Kyoung;Park Jong-Kweon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.5 s.96
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    • pp.455-464
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    • 2005
  • We have proposed a model of a thermal voltage converter(TVC) using the trans-impedance of lossy transmission line and developed a calculation program for ac-dc transfer difference of the TVC. The proposed TVC consists of a thermo-element(f) and a range resistor wire connected in series at the center of coaxial cylinder. The range resistor wire is used to extend the measurement range of the n. The calculated ac-dc transfer differences of the proposed TVC by simulation agree well with the measured values within the uncertainties. The simulated and measured values are agreed within $1{\mu}V/V$ from 40 Hz to 10kHz, within $5{\mu}V/V$ from 20kHz to 100MHz, and within $12{\mu}V/V$ from 200kHz to 1 MHz.