이중 기판 결함 접지 구조를 이용한 비대칭 윌킨슨 전력 분배기

임종식(Jongsik Lim),구재진(Jae-Jin Koo),오성민(Seongmin Oh),정용채(Yongchae Jeong),안달(Dal Ahn) 한국전자파학회 2007 한국전자파학회논문지 Vol.18 No.11

종래의 DGS를 이용한 초고주파 회로의 메탈 패키징(metal packaging)시 존재했던 DGS의 접지면 접촉 문제를 해결하고자, 본 논문에서는 이중 기판 결함 접지 구조 구조를 제안하고, 이를 1:4 비대칭 전력 분배기에 적용한 응용예를 제시한다. 이중 기판에 구현된 사각형 DGS는 종래와 같이 마이크로스트립 선로의 특성 임피던스를 표준형 선로보다 크게 증가시킨다. 이중 기판 DGS 구조를 형성하기 위하여 제2유전체 기판이 DGS가 구현된 기판면의 바닥 접지면에 접합된다. 따라서 제2유전체 기판이 메탈 패키지 바닥면에 장착되므로, DGS가 직접 패키지 접촉되는 것을 막을 수 있다. 초고주파 회로 응용예를 보이기 위해, 이중 기판 DGS를 이용하여 패키지 접지 문제를 해결한 1:4 비대칭 전력 분배기의 설계 및 측정 결과가 제시되는데, 시뮬레이션과 측정 결과에 있어서 잘 일치하는 특성을 보인다. A novel 1:4 unequal wilkinson power divider using rectangular-shaped defected ground structure(DGS) in double layered substrate is proposed for removing the ground problem of DGS in packaging. Rectangular-shaped DGS produces the transmission line having much higher characteristic impedance than standard microstrip line. The proposed unequal divider is composed of DGS and double layered substrate in order to be free from the ground problem of DGS patterns in packaging in metal housings. The second substrate is attached to the first substrate which contains DGS pattern on its ground plane at the bottom side to form the double layered substrate. In order to show the validity of the proposed DGS in the double layered substrate, a 1:4 unequal power divider is designed and measured. The predicted and measured performances are shown with an excellent agreement between them.

마이크로파 버랙터 다이오드의 실제 사용 조건에서의 실험적 등가회로

임종식(Jongsik Lim),이준(Jun Lee),이재훈(Jaehoon Lee),한상민(Sang-Min Han),안달(Dal Ahn) 한국정보기술학회 2010 한국정보기술학회논문지 Vol.8 No.8

An empirical equivalent circuit under practical application conditions of microwave varactor diodes is described. The equivalent circuit of varactor diodes in the data sheet provided by the manufacturer consists of adjustable junction capacitance(C<SUB>j</SUB>) which is inherent, parasitic inductance(L<SUB>p</SUB>) and capacitance (C<SUB>p</SUB>). However they are not accurate under the practical usage situation in most case, because the effects of dielectric substrate and via-holes are not considered for the practical usage situation. In this work, the equivalent circuit including the effective parasitic inductance(L<SUB>p,eff</SUB>) which contains the effect of the practical dielectric substrate and via-holes is extracted. The sample diode, MSV34,060-0805-2, is adopted as an example, and its C<SUB>j</SUB>, L<SUB>p</SUB> and C<SUB>p</SUB> on the data sheet are 0.4pF, 0.4nH and 0.06pF, while the empirically extracted C<SUB>j</SUB>, L<SUB>p,eff</SUB> and C<SUB>p</SUB> are 0.487pF, 1.526nH and 0.121pF, respectively. In addition, the extracted L<SUB>p,eff</SUB> and C<SUB>p</SUB> under the variable bias voltages of 0~15V are 1.476~1.567nH and 0.109~0.133pF, which are fairly uniform values with a good reliability.

가유전체 기판과 DGS를 이용한 링 하이브리드의 설계

임종식(Jongsik Lim),권경훈(Kyunghoon Kwon),도한주(Hanjoo Do),안달(Dal Ahn) 한국산학기술학회 2014 한국산학기술학회 학술대회 Vol.- No.-

가유전체 기판구조와 결함접지구조를 지니는 마이크로스트립 전송선로의 전기적 길이가 증가되는 원 리를 이용하여 설계된 링 하이브리드 커플러에 대하여 기술한다. 설계된 커플러는 가유전체 기판구조 나 결함접지구조의 어느 한 가지만 있는 경우에 비하여 65.2% - 53.7%의 크기를 갖는다. 회로가 소형 화되어 설계된 이후에도 전기적인 성능은 그대로 유지됨을 보인다.

DGS 전송선로의 등가회로와 전파지연계수에 대한 재고찰

林鍾植(Jongsik Lim),具滋慶(Jakyung Koo),韓相敏(Sang-Min Han),鄭龍采(Yongchae Jeong),安達(Dal Ahn) 대한전기학회 2008 전기학회논문지 Vol.57 No.11

A frequency-dependent slow-wave factor (SWF) and equivalent circuit model of transmission line with defected ground structures (DGS) is described. Once S-parameters of a DGS transmission line are given, the conventional frequency-independent equivalent circuit elements are extracted using 3㏈ cutoff and resonant frequencies (Fc and Fo) as the first step. Using the initial equivalent elements and simple transmission line theories, a frequency-dependent equivalent transmission line model is established through an analytical method, and finally the frequency-dependent SWF is calculated. The proposed equivalent circuit model and SWF are frequency-dependent and more reliable because even small insertion loss within available passband is considered, while they have been independent of frequency.

접지 접촉 문제가 없는 새로운 DGS 비대칭 브랜치 라인 하이브리드 결합기

林鍾植(Jongsik Lim),車顯源(Hyeonwon Cha),鄭龍采(Yongchae Jeong),朴雄熙(Ung-Hee Park),安達(Dal Ahn) 대한전기학회 2008 전기학회논문지 Vol.57 No.8

A 10 ㏈ branch Line hybrid coupler included with defected ground structure (DGS) is proposed. In this contribution, a contact between the grounded metal housing and DGS is avoided, which has been a serious problem in applying DGS to high frequency circuits. An isolation between the metal housing and the DGS pattern is provided by inserting additional substrate between DGS and the metal package. Therefore, it is possible to design branch line hybrid couplers having highly asymmetric power dividing ratio using these DGS structure, which is demonstrated in this paper. The designed and fabricated branch line hybrid coupler using DGS is well packaged in a metal housing without touching the ground metal directly. The measurement is performed under realistic practical operating situations because it is packaged in a metal housing. The measured performances of the fabricated 10㏈ coupler shows a 1:9 asymmetric power dividing ratio at output ports, as predicted. In addition, the measured performances in terms of matching, isolation, and phase difference are in excellent agreement with the simulated characteristics.

DGS와 가유전체 기판을 결합하여 소형화한 전력분배기

임종식(Jongsik Lim),권경훈(Kyunghoon Kwon),정용채(Yongchae Jeong),안달(Dal Ahn) 한국정보기술학회 2014 한국정보기술학회논문지 Vol.12 No.5

In this paper, a size-reduced Wilkinson power divider designed by combining defected ground structure(DGS) and artificial dielectric substrate(ADS), or substrate integrated artificial dielectric(SIAD), is discussed. DGS increases the equivalent inductance per unit length of transmission line, while ADS supplies the additional equivalent capacitance due to the periodically inserted metalized via-holes. Because both DGS and ADS produce the additional electrical length of transmission line, the physical length of the transmission line should be reduced to keep the required electrical length. ADS consists of 5mils and 31mils dielectric substrates with 2.2 of dielectric constant. The size of the designed divider is only 55.67% and 79.43% of DGS-only-inserted and ADS-only-inserted dividers, respectively. The measured power dividing ratio(S21 and S31) are -3.19dB and -3.32dB. In addition, the measured matching and isolation between output ports are ?20.94dB and -23.11dB, which agree well with the predicted S-parameters.

마이크로파 회로의 성능 측정을 위한 테스트 픽스춰의 개발

임종식(Jongsik Lim),박형식(Hyung-Sik Park),진철호(Cheul-Ho Jin),한상민(Sang-Min Han),안달(Dal Ahn) 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.10

본 논문에서는 무선시스템에 사용되는 마이크로파 회로의 성능을 측정하기 위한 마이크로파 테스트 픽스춰의 개발에 대하여 기술한다. 마이크로파 회로의 성능을 측정하기 위해서는, 프로토타입 회로의 입출력단에 동축형 RF컨넥터를 납땜하고, 벡터 회로망 분석기라는 장비를 이용하여 S-파라미터 특성을 측정하는 것이 기본이다. 그런데 어떤 회로에 RF컨넥터가 납땜으로 부착되면 컨넥터의 교체나 수리가 필요할 경우에, 기존의 납땜 부위를 제거해야 하는 불편이 매우 크다. 이에 본 연구에서는 컨넥터의 납땜 없이도 초고주파 회로의 성능을 편리하게 측정할 수 있는 테스트 픽스춰를 개발한다. 개발된 픽스춰에는 탈부착이 가능한 RF컨넥터가 입출력 단자에 기계적으로 체결되어 있다. 따라서 마이크로파 신호의 전달이 납땜 대신 기계적 접촉 방식으로 이루어지므로 매우 편리하고 빠르며 반복 측정이 가능하다. 개발된 픽스춰를 이용하면 초고주파 회로의 성능 측정에 소요되는 시간이 종래의 컨넥터 납땜 방법에 비하여 1/40 이하로 줄어든다. This paper describes the development of a microwave test fixture that measures the performance of microwave circuits for wireless systems. To measure the performance of microwave circuits conventionally, coaxial RF connectors are soldered to the input/output ports of the prototype circuit, and S-parameters of the circuits are measured on vector network analyzers. However, once the RF connector is soldered to the circuit, it is not easy to replace it with another one because it is very difficult to remove the soldered section. In this work, a test fixture is developed that measures microwave circuits easily without soldered connectors. The proposed fixture adapts RF connectors at the input/output ports, providing a mechanical contact without soldering. Instead of through solder, the microwave signal flows through contact points between the mechanically combined RF connectors and the microwave circuits so measurements can be made easily, quickly, and repeatedly. The required time for measurement using the developed fixture is shorter than 1/40 of the conventional soldered connector method.

기판적층 가유전체 전송선로의 효과적 설계 및 파라메트릭 연구

임종식(Jongsik Lim),구자경(Jakyung Koo),이준(Jun Lee),이재훈(Jaehoon Lee),한상민(Sang-Min Han),안달(Dal Ahn) 한국정보기술학회 2010 한국정보기술학회논문지 Vol.8 No.5

In this paper, an efficient design and simulation method for exact characteristic impedance of the transmission line with substrate integrated artificial dielectric (SIAD) is described. The optimized square via-hole is adopted instead of circular via structure for the efficient simulation to get the reduced time and computing cost. The simulated characteristic impedance is proved through the practically measured result which is in good agreement with the simulation. The enormous computing time and cost required for the simulation of the transmission line with hundreds of circular via holes are quitely reduced by adopting the square via hole in simulation. Transmission lines with SIAD and various characteristic impedances are designed and fabricated, and the agreement between simulation and measurement is shown. In addition, the parametric study results, which illustrate the characteristic impedance of SIAD transmission lines depends on the via-hole size and pitch, are presented with an excellent agreement.

결함 마이크로스트립 구조를 이용한 적층형 4-Way 전력분배기의 설계

임종식(Jongsik Lim),윤원상(Won-Sang Yoon),최희윤(Heeyoun Choi),한상민(Sang-Min Han),안달(Dal Ahn) 한국정보기술학회 2017 한국정보기술학회논문지 Vol.15 No.6

This paper proposes a design of multi-layered 4-way power divider using defected microstrip structure (DMS). DMS has defected patterns on the plane of transmission lines instead of the ground plane. Well known advantages of periodic structures are also observed in DMS such as increased line impedance for the same width, broadened line width for the same line impedance, and enlarged electrical length for the same physical length. In addition, there is no ground-contact problem, so it is much more convenient to design and fabricate multi-layered circuits using DMS patterns. As an application example to circuit design, a DMS 4-way power divider is designed and measured. The design and fabrication processes are much easier than previous works, while the measured performances prove the proposed design is well desirable with the good agreement between simulation and measurement.

고출력 트랜지스터 패키지 설계를 위한 새로운 와이어 본딩 방식

林鍾植(Jongsik Lim),吳星?(Seongmin Oh),朴天仙(Chunseon Park),李龍鎬(Yongho Lee),安達(Dal Ahn) 대한전기학회 2008 전기학회논문지 Vol.57 No.4

This paper describes the design of high power transistor packages using high power chip transistor dies, chip capacitors and a new wire bonding technique. Input impedance variation and output power performances according to wire inductance and resistance for internal matching are also discussed. A multi crossing type (MCT) wire bonding technique is proposed to replace the conventional stepping stone type (SST) wire bonding technique, and eventually to improve the output power performances of high power transistor packages. Using the proposed MCT wire bonding technique, it is possible to design high power transistor packages with highly improved output power compared to SST even the package size is kept to be the same.