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Myunghoi Kim,Kyoungchoul Koo,Joungho Kim,Jiseong Kim IEEE 2012 IEEE microwave and wireless components letters Vol.22 No.8
<P>In this letter, we propose a vertical inductive bridge electromagnetic bandgap (VIB-EBG) structure for size reduction of a unit cell and the wideband suppression of simultaneous switching noise (SSN) in a multi-layer package. With the proposed vertical inductive bridge, the inductance of an EBG unit cell is effectivel increased within a compact unit cell size. Compared to the previous planar bridge EBG structure, the proposed VIB-EBG structure achieves an 86% enhancement of the fractional stopband bandwidth and a 58% reduction in unit cell size. The starting frequency of the first bandgap (f<SUB>L</SUB>) is significantly reduced from 4.0 to 1.7 GHz. Wideband SSN suppression with a size reduction was successfully verified by HFSS simulations and measurements.</P>
Myunghoi Kim,Kyoungchoul Koo,Chulsoon Hwang,Yujeong Shim,Joungho Kim,Jonghoon Kim IEEE 2012 IEEE transactions on electromagnetic compatibility Vol.54 No.3
<P>In this paper, we propose a compact and wideband electromagnetic bandgap (EBG) structure using a defected ground structure (DGS) to significantly enhance the wideband suppression of power/ground noise coupling in multilayer packages and printed circuit boards. The proposed EBG structure is implemented simply by adding a rectangular-shaped DGS which is etched periodically onto the ground plane without changing any other geometrical parameter from a mushroom-type EBG structure. The DGS effects on the f<SUB>L</SUB> and f<SUB>U</SUB> are thoroughly analyzed using the dispersion characteristics. We experimentally verified that the proposed EBG structure achieved the wideband power/ground noise suppression (below -40 dB) between 2.5 and 16.2 GHz. In addition, we demonstrated the considerable reduction in f<SUB>L</SUB> from 3.4 to 2.5 GHz and a significant increase in f<SUB>U</SUB> from 9.1 to 16.2 GHz when compared with the mushroom-type EBG structure.</P>
A Wideband and Compact EBG Structure With a Circular Defected Ground Structure
Myunghoi Kim,Dong Gun Kam IEEE 2014 IEEE transactions on components, packaging, and ma Vol.4 No.3
<P>We propose a new analysis method to determine the bandgap characteristics of an electromagnetic bandgap structure with a defected ground structure (DGS). The proposed method is based on a 1-D segmented transmission line model and a piecewise linear approximation of Zo within a unit cell. Although the previous method is only applicable to rectangular DGSs (RDGSs), the proposed method is applicable to any DGS shapes. As an example, the proposed method is applied to a circular DGS and shows a good agreement with full-wave simulations of the unit cell and measurements of 11 × 11 unit cells. The circular DGS achieves a 15% improvement in the stopband bandwidth over the RDGS with the same perforation area. The proposed method allows us to explore a variety of DGS shapes in the search for better stopband characteristics. It also offers the basis for numerical optimization techniques to be used in synthesizing DGS shapes to meet required stopband characteristics.</P>
Electrical Design for Noise Suppression of High-Speed Digital Communication Links
Myunghoi Kim,Hongyeal Lee,Inbok Yom 한국정보통신학회 2016 2016 INTERNATIONAL CONFERENCE Vol.8 No.1
We propose an electrical design technique for noise-tolerant digital channels carrying multi-gigabit data. In the electrical layer of recent multi-gigabit digital channels, electrical imbalances between data channels induce a serious problem of electrical noises, thus degrading overall system performances. To suppress an electrical noise and improve a system performance, an impedance-controlled channel design is presented. By using a circuit simulation, the noise suppression of the proposed technique is demonstrated.
구조분할 해석기법 기반 전원보드 공통모드 노이즈 감쇠 설계
김명회(Myunghoi Kim),노동규(Dongkyu Roh),정성석(Sungseok Jeong),곽규민(Kyumin Kwak) 한국전자파학회 2018 한국전자파학회논문지 Vol.29 No.2
본 논문에서는 전원보드의 공통모드 노이즈 감쇠를 위한 디커플링 커패시터 회로를 효율적으로 시뮬레이션할 수 있는 구조분할 해석기법을 제시한다. 제시하는 구조분할 해석기법이 적용된 전원보드 설계에서는 보드를 두 부분으로 구조분할하였으며, 분할된 구조와 커패시터 회로의 임피던스 파라미터를 재결합하기 위한 방법을 제시하였다. 구조분할 해석기법을 적용함으로써 공통모드 노이즈 감쇠 시뮬레이션에 수행되는 시간을 46 % 이상 단축하였다. In this paper, we present a design technique for the suppression of common-mode(CM) noise in switched-mode power supply boards using the segmentation method. By applying the segmentation method, the example structure is decomposed into two segments with decoupling capacitors and a recombination matrix is extracted for the segments. The effects of the decoupling capacitor on CM noise suppression are examined. The simulation time is significantly reduced on using the segmentation method.
Minchul Shin,Myunghoi Kim,Jiseong Kim,Joungho Kim,Seungyoung Ahn IEEE 2014 IEEE transactions on components, packaging, and ma Vol.4 No.1
<P>This paper proposes a wideband continuous-time passive equalizer with an embedded cavity structure that is more compact in size and enables lower-cost processing than conventional technologies. The proposed passive equalizer is composed of a lumped resistor and capacitance in a cavity structure generated by a parasitic channel parasitic component, such as a package ball pad. This equalizer design in which the capacitance is embedded in the cavity structure offers the advantages of reducing the additional occupied printed circuit board (PCB) area and of enabling a small-sized equalizer with a large capacitance for application in high-density systems. For a 40-cm transmission line on PCB with a data rate of 12.5 Gb/s, the measured eye diagram is successfully demonstrated and the eye opening significantly improved to 81.1 mV, with a timing jitter of 28.7 ps.</P>
System-on-package ultra-wideband transmitter using CMOS impulse generator
Lee, Junwoo,Park, Young-Jin,Kim, Myunghoi,Yoon, C.,Kim, Joungho,Kim, Kwan-Ho Professional Technical Group on Microwace Theory a 2006 IEEE transactions on microwave theory and techniqu Vol.54 No.4
In this paper, a low-cost CMOS ultra-wideband (UWB) impulse transmitter module with a compact form factor is proposed for impulse-radio communications. The module consists of a CMOS impulse generator, a compact bandpass filter (BPF), and a printed planar UWB antenna. The impulse generator is designed using a Samsung 0.35-μm CMOS process for low-cost and low-power fabrication. The measurement shows the fabricated chip makes a train of sharp triangular pulses with a peak voltage of about 2.8 V under the supply voltage of 3.3 V. To make an impulse fit the Federal Communications Commission (FCC) spectrum mask, the compact BPF is developed using a coupled strip line and a tapered stub. Also, the compact planar UWB antenna is developed. All of the components of the UWB transmitter module are fabricated on a single package using system-on-package technology for miniaturization. The proposed UWB transmitter is tested in an office environment. The measured results show that the generated UWB signal meets the FCC regulation, and the peak-to-peak amplitude of received UWB signal at 1-m distance on line of sight is 16 mVpp with a 10-dB-gain low-noise amplifier in the receiver.
A Compact EBG Structure With Wideband Power/Ground Noise Suppression Using Meander-Perforated Plane
[Institute of Electrical and Electronics Engineers 2015 IEEE transactions on electromagnetic compatibility Vol.57 No.3
<P>In this letter, we propose a miniaturized and wideband electromagnetic bandgap (EBG) structure with a meander-perforated plane (MPP) for power/ground noise suppression in multilayer printed circuit boards. The proposed MPP enhances the characteristic impedance of the EBG unit cell and improves the slow-wave effect, thus achieving the significant size reduction and the stopband enhancement. To explain the prominent results, a dispersion analysis for the proposed MPP-EBG structure is developed. Compared to a mushroom-type EBG structure, it is experimentally demonstrated that the MPP-EBG structure presents a 57% reduction in the start frequency of the bandgap, which leads to a 74% reduction in a unit cell size. In addition, the MPP-EBG structure considerably improves the noise suppression bandwidth (-40 dB) from 0.8 to 4.9 GHz compared to the mushroom-type EBG structure.</P>
Suppression of Parallel Plate Modes Using Edge-Located EBG Structure in High-Speed Power Bus
Cho, Jonghyun,Kim, Myunghoi The Korea Institute of Information and Commucation 2016 Journal of information and communication convergen Vol.14 No.4
An edge-located electromagnetic bandgap (EL-EBG) structure using a defected ground structure (DGS) is proposed to suppress resonant modes induced by edge excitation in a two-dimensional planar parallel plate waveguide (PPW). The proposed EL-DGS-EBG PPW significantly mitigates multiple transverse-magnetic (TM) modes in a wideband frequency range corresponding to an EBG stopband. To verify the wideband suppression, test vehicles of a conventional PPW, a PPW with a mushroom-type EBG structure, and an EL-DGS-EBG PPW are fabricated using a commercial process involving printed circuit boards (PCBs). Measurements of the input impedances show that multiple resonant modes of the previous PPWs are significantly excited through an input port located at a PPW edge. In contrast, resonant modes in the EL-DGS-EBG PPW are substantially suppressed over the frequency range of 0.5 GHz to 2 GHz. In addition, we have experimentally demonstrated that the EL-DGS-EBG PPW reduces the radiated emission from -24 dB to -44 dB as compared to the conventional PPW.
Wideband Suppression of Radiated Emissions from a Power Bus in High-Speed Printed Circuit Boards
Shim, Yujeong,Kim, Myunghoi The Korea Institute of Information and Commucation 2016 Journal of information and communication convergen Vol.14 No.3
We present experimental demonstrations of electromagnetic bandgap (EBG) structures for the wideband suppression of radiated emissions from a power bus in high-speed printed circuit boards (PCBs). In most of the PCB designs, a parallel plate waveguide (PPW) structure is employed for a power bus. This structure significantly produces the wideband-radiated emissions resulting from parallel plate modes. To suppress the parallel plate modes in the wideband frequency range, the power buses based on the electromagnetic bandgap structure with a defected ground structure (DGS) are presented. DGSs are applied to a metal plane that is connected to a rectangular EBG patch by using a via structure. The use of the DGS increases the characteristic impedance value of a unit cell, thereby substantially improving the suppression bandwidth of the radiated emissions. It is experimentally demonstrated that the DGS-EBG structure significantly mitigates the radiated emissions over the frequency range of 0.5 GHz to 2 GHz as compared to the PPW.