Compact and Wideband Coupled-Line 3-㏈ Ring Hybrids

Hee-Ran Ahn(안희란),Jungjoon Kim(김정준),Bumman Kim(김범만) 한국전자파학회 2008 한국전자파학회논문지 Vol.19 No.8

두 종류의 넓은 대역폭을 갖는 ring hybrids(하나는 coupled line이 포함되어 있고, 다른 하나는 left-handed transmission line을 포함한 ring hybrids)가 비교되었으며, 비교 결과로부터 coupled line을 포함한 ring hybrid가 모든 면에서 우수한 특성을 가짐을 보여줬다. 그러나, coupled line을 포함한 ring hybrid는 -3 ㏈ coupling power를 가질 경우에 한해서만이 perfect matching이 이루어지기 때문에, perfect matching을 갖는 coupled line ring hybrid는 2차원으로 구현하기는 거의 불가능하다. 이 문제를 해결하기 위해서 coupled line을 해석했고, 그 해석 결과로부터 coupling coefficient에 관계없이 어느 경우에도 perfect matching을 이룰 수 있는 설계 식을 유도했다. 이 설계식을 이용하여, transmission line의 길이가 π보다 큰 경우에도 적용될 수 있는 크기를 줄이기 위한 새로운 형태의 transmission line 등가회로를 제시했다. 이 새로운 형태의 transmission line의 등가회로를 이용하면 기존의 ring hybrid의 3λ/4의 transmission line을 줄이는 데 사용할 수 있기 때문에 ring hybrid의 크기를 더욱 줄이는 데 장점이 될 수 있다. 이 등가회로를 증명하기 위해서, coupling power를 고정하고 또는 transmission line의 길이를 고정하는 2가지 형태의 simulation을 하였으며, 대역폭은 coupled line의 coupling power에 직접적인 상관 관계가 있음을 보였다. 기존의 등가회로와 새로운 형태의 등가회로를 이용하여, 작고 넓은 대역폭을 가지는 ring hybrid를 제시하였다. 새로 제시된 ring hybrid를 이용하여, 기존의 ring hybrid와 비교하였다. 비교 결과로부터, 본 논문에서 제시한 ring hybrid의 전체 ring 둘레가 1/3보다 더 작음에도 불구하고, 대역폭이 훨씬 넓음을 보여줬다. 작고 넓은 대역폭을 가지는 ring hybrid를 측정했으며, 측정 결과는 -2.78 ㏈, -3.34 ㏈, -2.8 ㏈, -3.2 ㏈의 power division 특성을 보여줬으며, matching과 isolation은 20 % 이상의 대역폭에서 -20 ㏈보다 좋은 특성을 보여줬다. In this paper, two types of wideband 3-㏈ ring hybrids are compared and discussed to show the ring hybrid with a set of coupled-line sections better. However, the better one still has a realization problem that perfect matching can be achieved only with -3 ㏈ coupling power. To solve the problem, a set of coupled-line sections with two shorts is synthesized using one- and two-port equivalent circuits and design equations are derived to have perfect matching, regardless of the coupling power. Based on the design equations, a modified Π-type of transmission-line equivalent circuit is newly suggested. It consists of coupled-line sections with two shorts and two open stubs and can be used to reduce a transmission-line section, especially when its electrical length is greater than π. Therefore, the 3λ/4 transmission-line section of a conventional ring hybrid can be reduced to less than π/2. To verify the modified Π-type of transmission- line equivalent circuit, two kinds of simulations are carried out; one is fixing the electrical length of the coupled-line sections and the other fixing its coupling coefficient. The simulation results show that the bandwidths of resulting small transmission lines are strongly dependent on the coupling power. Using modified and conventional Π-types of transmission-line equivalent circuits, a small ring hybrid is built and named a compact wideband coupled-line ring hybrid, due to the fact that a set of coupled-line sections is included. One of compact ring hybrids is compared with a conventional ring hybrid and the compared results demonstrate that the bandwidth of a proposed compact ring hybrid is much wider, in spite of being more than three times smaller in size. To test the compact ring hybrids, a microstrip compact ring hybrid, whose total transmission-line length is 220°, is fabricated and measured. The measured power divisions(S₂₁, S₄₁, S₂₃ and S₄₃) are -2.78 ㏈, -3.34 ㏈, -2.8 ㏈ and -3.2 ㏈, respectively at a design center frequency of 2 ㎓, matching and isolation less than -20 ㏈ in more than 20 % fractional bandwidth.

Compact and Wideband Coupled-Line 3-dB Ring Hybrids

안희란,김정준,김범만,Ahn, Hee-Ran,Kim, Jung-Joon,Kim, Bum-Man The Korean Institute of Electromagnetic Engineerin 2008 한국전자파학회논문지 Vol.19 No.8

두 종류의 넓은 대역폭을 갖는 ring hybrids(하나는 coupled line이 포함되어 있고, 다른 하나는 left-handed transmission line을 포함한 ring hybrids)가 비교되었으며, 비교 결과로부터 coupled line을 포함한 ring hybrid가 모든 면에서 우수한 특성을 가짐을 보여줬다. 그러나, coupled line을 포함한 ring hybrid는 -3 dB coupling power를 가질 경우에 한해서만이 perfect matching이 이루어지기 때문에, perfect matching을 갖는 coupled line ring hybrid는 2차원으로 구현하기는 거의 불가능하다. 이 문제를 해결하기 위해서 coupled line을 해석했고, 그 해석 결과로부터 coupling coefficient에 관계없이 어느 경우에도 perfect matching을 이룰 수 있는 설계 식을 유도했다. 이 설계식을 이용하여, transmission line의 길이가 ${\pi}$보다 큰 경우에도 적용될 수 있는 크기를 줄이기 위한 새로운 형태의 transmission line 등가회로를 제시했다. 이 새로운 형태의 transmission line의 등가회로를 이용하면 기존의 ring hybrid의 $3\;{\lambda}/4$의 transmission line을 줄이는 데 사용할 수 있기 때문에 ring hybrid의 크기를 더욱 줄이는데 장점이 될 수 있다. 이 등가회로를 증명하기 위해서, coupling power를 고정하고 또는 transmission line의 길이를 고정하는 2가지 형태의 simulation을 하였으며, 대역폭은 coupled line의 coupling power에 직접적인 상관 관계가 있음을 보였다. 기존의 등가회로와 새로운 형태의 등가회로를 이용하여, 작고 넓은 대역폭을 가지는 ring hybrid를 제시하였다. 새로 제시된 ring hybrid를 이용하여, 기존의 ring hybrid와 비교하였다. 비교 결과로부터, 본 논문에서 제시한 ring hybrid의 전체 ring 둘레가 1/3보다 더 작음에도 불구하고, 대역폭이 훨씬 넓음을 보여줬다. 작고 넓은 대역폭을 가지는 ring hybrid를 측정했으며, 측정 결과는 -2.78 dB, -3.34 dB, -2.8 dB, -3.2 dB의 power division 특성을 보여줬으며, matching과 isolation은 20 % 이상의 대역폭에서 -20 dB보다 좋은 특성을 보여줬다. In this paper, two types of wideband 3-dB ring hybrids are compared and discussed to show the ring hybrid with a set of coupled-line sections better. However, the better one still has a realization problem that perfect matching can be achieved only with -3 dB coupling power. To solve the problem, a set of coupled-line sections with two shorts is synthesized using one- and two-port equivalent circuits and design equations are derived to have perfect matching, regardless of the coupling power. Based on the design equations, a modified ${\Pi}-type$ of transmission-line equivalent circuit is newly suggested. It consists of coupled-line sections with two shorts and two open stubs and can be used to reduce a transmission-line section, especially when its electrical length is greater than ${\pi}$. Therefore, the $3\;{\lambda}/4$ transmission-line section of a conventional ring hybrid can be reduced to less than ${\pi}/2$. To verify the modified ${\Pi}-type$ of transmission- line equivalent circuit, two kinds of simulations are carried out; one is fixing the electrical length of the coupled-line sections and the other fixing its coupling coefficient. The simulation results show that the bandwidths of resulting small transmission lines are strongly dependent on the coupling power. Using modified and conventional ${\Pi}-types$ of transmission-line equivalent circuits, a small ring hybrid is built and named a compact wideband coupled-line ring hybrid, due to the fact that a set of coupled-line sections is included. One of compact ring hybrids is compared with a conventional ring hybrid and the compared results demonstrate that the bandwidth of a proposed compact ring hybrid is much wider, in spite of being more than three times smaller in size. To test the compact ring hybrids, a microstrip compact ring hybrid, whose total transmission-line length is $220^{\circ}$, is fabricated and measured. The measured power divisions($S_{21}$, $S_{41}$, $S_{23}$ and $S_{43}$) are -2.78 dB, -3.34 dB, -2.8 dB and -3.2 dB, respectively at a design center frequency of 2 GHz, matching and isolation less than -20 dB in more than 20 % fractional bandwidth.

Equivalent Transmission-Line Sections for Very High Impedances and Their Application to Branch-Line Hybrids with Very Weak Coupling Power

Hee-Ran Ahn,Bumman Kim 한국전자파학회JEES 2009 Journal of Electromagnetic Engineering and Science Vol.9 No.2

As operating frequency is raised and as more integration with active and passive elements is required, it becomes difficult to fabricate more than 120 Ω characteristic impedance of a microstrip line. To solve this problem, an equivalent high impedance transmission-line section is suggested, which consists mainly of a pair of coupled-line sections with two shorts. However, it becomes a transmission-line section only when its electrical length is fixed and its coupling power is more than half. To have transmission-line characteristics(perfect matching), independently of coupling power and electrical length, two identical open stubs are added and conventional design equations of evenand odd-mode impedances are modified, based on the fact that the modified design equations have the linear combinations of conventional ones. The high impedance transmission-line section is a passive component and therefore should be perfectly matched, at least at a design center frequency. For this, two different solutions are derived for the added open stub and two types of high impedance transmission-line sections with 160 Ω characteristic impedance are simulated as the electrical lengths of the coupled-line sections are varied. The simulation results show that the determination of the available bandwidth location depends on which solution is chosen. As an application, branch-line hybrids with very weak coupling power are investigated, depending on where an isolated port is located, and two types of branch-line hybrids are derived for each case. To verify the derived branch-line hybrids, a microstrip branch-line hybrid with ?15 ㏈ coupling power, composed of two 90° and two 270° transmission-line sections, is fabricated on a substrate of εr= 3.4 and h=0.76 ㎜ and measured. In this case, 276.7 Ω characteristic impedance is fabricated using the suggested high impedance transmission-line sections. The measured coupling power is ?14.5 ㏈, isolation and matching is almost perfect at a design center frequency of 2 ㎓, showing good agreement with the prediction.

탭 선로를 이용한 새로운 결합선로 여파기 설계법

우동식,김강욱 한국전자파학회 2004 한국전자파학회논문지 Vol.15 No.11

본 논문에서는 다단 결합선로 여파기(edge coupled-line filter)의 입출력단을 탭 선로(tapped-line)의 형태로 구현하기 위하여 등가회로 기반의 새로운 설계법을 개발하여 적용하였다. 다단 결합선로 여파기는 입출력단의 선로 간격이 매우 좁아서(수 mil) 제작하기가 힘든 결함이 있는데, 이를 탭 선로로 대체함으로써 제작 시 오차에 덜 민감하고 밀링머신으로 쉽게 제작할 수 있도록 하였다. 또한, 본 논문에서 제안된 간단한 설계법을 사용하면 20 GHz 이하의 주파수 대역에서 20 % 이하의 대역폭 특성을 갖는 탭 선로의 파라미터를 얻을 수 있으며, 이를 바탕으로 정확한 탭 선로 여파기를 설계할 수 있다. In this paper, a new design method fur tapped coupled-line filters has been developed. The design equations for this tapped-line filter have been obtained using a new equivalent circuit model of tapped lines. These tapped-lines replace input/output coupled lines of the conventional edge coupled-line filters, which tend to have very narrow line gaps(few mils). Therefore, tapped coupled-line filters tend to be less sensitive to filter fabrication tolerances and to be easily fabricated using milling tools. The new filter design algorithm allows very accurate filter design for frequencies up to 20 GHz and bandwidth less than 20 %.

Design and Implementation of Slot-coupled Microstrip Components for Wideband Butler Matrix

이동학,양두영 한국지식정보기술학회 2017 한국지식정보기술학회 논문지 Vol.12 No.4

The design of a slot-coupled directional coupler and a slot-coupled crossover for use in a switched beamforming network operating over wideband has been presented and discussed. In order to achieve wideband characteristics, the coupler and the crossover use slot-coupled microstrip transmission line (MTL) technology. Since the slot-coupled components have a structure in which the two signal lines on the top and bottom side are coupled to each other through the rectangular slot on the common ground plane, the amount of the combined signal is determined by the width of the slot, the width of the line and the height of the substrate. The width of the slot should be set to be wider than the width of signal line to induce proper coupling, and the width of the slot should be about 1.5 times to the width of the signal line. It can be seen that the coupling coefficient increases as the ratio of the width of the line to the height of the substrate increases, which means that the amount of the signal coupled to the output port increases as the width of the line increases. The proposed coupler and the crossover have been obtained high performance of 3±0.5dB coupling, 90±1° phase difference, and 0.5dB coupling and 45±3.5° phase shift in the operating frequency band, respectively. In addition, they have been implemented on the double-layered MTL in a small size and without intersecting lines on microstrip substrate.

다층형 결합 선로를 이용한 반송파 복원 회로 설계 제작

김영완,Kim, Young-Wan 한국정보통신학회 2009 한국정보통신학회논문지 Vol.13 No.10

본 논문에서는 다층형 결합 선로를 이용한 PSK 반송파 신호 복원 회로를 해석하고 설계 제작한다. 다층형 결합 선로 구조의 coupled line으로 구성되는 반송파 복원 6단자 소자는 다층형 구조를 가지며, 수신 전처리부의 6 단자 위상 상관기 구조와 동일한 구조를 갖는 일원화된 수신 구조 구현이 가능하다. 아울러 다층 결합 선로 6 단자 위상 상관기를 이용한 RML 기반 다중 모드 동기 복조형 반송파 신호 복원이 가능한 다층형 결합 선로 반송파 복원 회로 구조를 제안한다. 설계 제작된 다층형 결합 선로 구조 반송파 복원회로에 의한 직교 위상편이 방식 신호의 반송파 신호는 일정한 위상값과 반사 소자에 의해 발생되는 ${\pm}3o$ 이내인 위상차를 갖는 양호한 PSK 반송파 신호 특성을 나타내었다. The PSK carrier signal recovery circuit using multi-layer coupled line was analyzed and designed. The fabricated carrier recovery 6 port element with multi-layer coupled line structure gets the simple architecture. It is possible to implement the carrier signal recovery circuit of the same structure with the multi-layer six port phase correlator of the direct receiver front-end. Based on the analysis of RML carrier recovery circuit using the multi-layer coupled line 6-port phase correlator, the multi-layer coupled line carrier signal recovery structure for multi-mode coherent demodulation was proposed. The fabricated multi-layer coupled line carrier signal recovery circuit for quadrature phase shift-keying shows a good carrier signal characteristic with a constant phase and phase error below ${\pm}3o$.

PCB상에 놓여 있는 굽은 결합 선로의 누화 해석

한재권,박동철,Han, Jae-Kwon,Park, Dong-Chul 한국전자파학회 2007 한국전자파학회논문지 Vol.18 No.2

The electromagnetic coupling between transmission lines in PCB design can degrade the performance of equipment operations. The coupling phenomenon is caused by electromagnetic fields generated by the currents on the transmission lines and the risers. In this paper, an improved method of crosstalk analysis for bent coupled lines on a PCB is proposed and investigated. In the previous cascading method combined with circuit-concept approach, bent coupled lines are devided into sections and each section is represented by ABCD matrix and then they are cascaded. In the proposed method, the crosstalk of bent coupled lines is calculated by the modified circuit-concept approach, where the coupled region is not restricted to the region projected by a generator line on a receptor line but is the total length of receptor line in calculating the forcing terms. Finally, the accuracy of the proposed approach is verified by comparing the calculated results with the measured ones for several bent coupled-line examples. PCB 설계시 전송선간에 발생하는 전자기적 결합 현상은 장비의 동작을 저감시키는 요인이 될 수 있다. 이런 결합 현상은 전송선과 라이저를 통해 흐르는 전류에 의해 생기는 전자기계에 의해 발생한다. 본 논문에서는 PCB상에 놓여 있는 굽은 결합 선로의 누화를 해석하기 위한 개선된 방법을 제안하고 고찰해 보고자 한다. 굽은 결합 선로에 대한 기존의 누화 해석은 굽은 결합 선로의 굽은 지점을 기준으로 각 구간으로 나누고 각 구간을ABCD 행렬로 나타내어 이를 직렬 연결한 방법을 이용하였다. 하지만 본 논문에서 제안하는 누화 해석 방법은 기존의 방법과는 달리 결합 현상을 계산할 때의 결합 구간을 소스가 인가되는 전송선을 인접한 전송선으로 수직 투영시킨 구간만이 아닌 인접한 전송선의 전 구간에 영향을 준다고 보고 계산을 하는 개선된 회로 접근법에 의해 계산하였다. 마지막으로, 몇 가지 굽은 결합 선로 모델들에 대해서 계산한 결과와 측정한 결과를 비교함으로써 본 논문에서 제안하는 누화 해석 방법의 타당성을 보였다.

다단 브랜치라인으로 구성된 광대역 결합기 설계 및 구현

양두영 한국지식정보기술학회 2020 한국지식정보기술학회 논문지 Vol.15 No.4

In designing the branch line coupler, it is very important to set the impedance of each line because the amount of signal coupling at the output port is determined by the impedance of each line constituting the branch line. Since the coupling coefficient between the input and output ports is determined by the impedance condition of the line in the multi-stage branch line structure, the impedance of each line to obtain the desired coupling coefficient can be obtained by applying even-odd mode circuit analysis. In this paper, the multi-stage microstrip branch line structure is constructed and a hybrid coupling structure is used to distribute the half-power type of circuit lines connected to each port for signal transmission. We also obtained the broadband characteristics by optimizing the width and length of the line impedance to reduce the phase error within the operating range. We also analyzed the influence of the output signal amplitude and phase error on the beam pattern and beam steering direction obtained from the wide band design results of the five-stage branch line coupler. The fabricated hybrid branch line coupler has the operating frequency band of 2.15 GHz to 3.4 GHz, with a relative bandwidth of about 47%. In the band, the transmission characteristic and phase difference between output ports are less than 3.3 ± 0.5 dB and 90±1°. It shows good insertion loss, a half power and wide band characteristics.

π-형 전송선 급전 구조를 갖는 대역 통과 필터

배주석(Juseok Bae),임종식(Jongsik Lim),김귀수(Kwisoo Kim),안달(Dal Ahn) 한국전자파학회 2008 한국전자파학회논문지 Vol.19 No.2

본 논문에서는 일반적인 반 파장 평행 결합 선로 대역 통과 필터의 입?출력 결합 선로를 K-인버터로 변환하고, K-인버터를 π-형 전송선 등가로 대체함으로써 π-형 전송선 급전 구조를 갖는 구조의 대역 통과 필터를 제안하였다. 이 방법은 반 파장 결합 선로 대역 통과 필터의 입?출력 결합 선로 구현 문제에 대한 해결 방안을 제시한다. 또한, 기존의 탭 선로(tapped line) 구조의 설계 방법에 비해 설계 식이 매우 간단하고 정확하여, 특성의 적정화를 위한 노력과 시간을 상당히 줄일 수 있다. 제안된 이론을 바탕으로 π-형 전송선 급전 구조를 갖는 구조의 대역 통과 필터를 설계 및 제작하였고, 그 결과로부터 제안 방법의 타당성을 입증하였다. This paper proposed the band pass filter(BPF) with feeding structure using π-type transmission line by means of transforming the input/output coupled-lines of the half wavelength parallel coupled-line BPF into K-inverter, then substituting π-type transmission line equivalence for K-inverter. The proposed method supplies solution with what the half wavelength parallel coupled-line BPF's input/output coupled-lines are realized. Also it can quite reduce efforts and time needed to optimize filter performance when is compared to reported method using tapped line structure because formulas is very simple and accurate. On the basic of the proposed method, the BPF with feeding structure using π-type transmission line has been designed and fabricated. The validity of proposed method was proven by the measured result.

Investigation of Electromagnetic Field Coupling with Twisted Conducting Line by Expanded Chain Matrix

Yong-Sun Cho,Jong-Suk Ro,Yong-Seek Chung,Changyul Cheon,Hyun-Kyo Jung 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.2

In the current paper, we propose a new modeling algorithm to analyze the coupling between an incident electromagnetic field (EMF) and a twisted conducting line, which is a kind of non-uniform line. Typically, analysis of external field coupling to a uniform transmission line (TL) is implemented by the Baum-Liu-Tesche (BLT) equation so that the induced load responses can be obtained. However, it is difficult to apply this method to the analysis of a twisted conducting line. To overcome this limitation, we used a chain matrix composed of ABCD parameters. The proposed algorithm expands the dimension of the previous chain matrix to consider the EMF coupling effectiveness of each twisted pair, which is then applied to multi-conductor transmission line (MTL) theory. In addition, we included a comparative study that involves the results of each method applied in the conventional BLT equation and new proposed algorithm in the uniform two-wire TL case to verify the proposed method.