• ETRI Journal
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• 제46권4호
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• pp.571-580
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• 2024

A compact triple-band porous electromagnetic bandgap structure-loaded coplanar-waveguide-fed wearable antenna is introduced for applications of wireless body area networks. The porous structure is aimed to create a stopband or bandgap in the electromagnetic spectrum and increase breathability. The holes in the bottom electromagnetic bandgap surface increase the inductance, which in turn increases the bandwidth. The final design resonates at three bands with impedance bandwidths of 264 MHz, 100 MHz, and 153 MHz and maximum gains of 2.18 dBi, 6.75 dBi, and 9.50 dBi at 2.45 GHz, 3.5 GHz, and 5.5 GHz, respectively. In addition, measurements indicate that the proposed design can be deformed up to certain curvature and withstand human tissue loading. Moreover, the specific absorption rate remains within safe levels for humans. Therefore, the proposed antenna can suitably operate in the industrial, scientific, and medical, Bluetooth, Wi-Fi, and WiMAX bands for potential application to wireless body area networks.

• Journal of electromagnetic engineering and science
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• 제14권4호
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• pp.346-348
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• 2014

A dispersion analysis is performed to estimate the stopband characteristics of electromagnetic bandgap (EBG) structures with defected ground structures (DGS) of various shapes. Design guidelines are suggested for both elliptical and rectangular DGS patterns that result in a maximum stopband bandwidth for a given perforation area. This method provides a basis for numerical optimization techniques that can be used in synthesizing DGS shapes to meet bandgap requirements and layout constraints.

• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.237-243
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• 2017

This paper presents an analysis of the electromagnetic interference of a heterogeneous power bus where electromagnetic bandgap (EBG) cells are irregularly arranged. To mitigate electrical-noise coupling between high-speed circuits, the EBG structure is placed between parallel plate waveguide (PPW)-based power buses on which the noise source and victim circuits are mounted. We examine a noise suppression characteristic of the heterogeneous power bus in terms of scattering parameters. The characteristics of the dispersion and scattering parameters are compared in the sensitivity analysis of the EBG structure. Electric field distributions at significant frequencies are thoroughly examined using electromagnetic simulation based on a finite element method (FEM). The noise suppression characteristics of the heterogeneous power bus are demonstrated experimentally. The heterogeneous power bus achieves significant reduction of electrical-noise coupling compared to the homogeneous power buses that are adopted in conventional high-speed circuit design. In addition, the measurements show good agreement with the FEM simulation results.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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• pp.91-95
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• 2001

This paper presents that photonic bandgap structures suppressing the propagation of surface waves can improve the performance of the patch antennas on thick high dielectric constant substrate. The forbidden propagation of surface wave due to the photonic bandgap enhances the radiation efficiency and reduce the back radiation drastically with maintaining the small size and wide bandwidth of the antennas.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.380-383
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• 2002

본 논문에서는 20㎓~50㎓ 대역에서 2 차원 PBG(Photonic-Bandgap) 구조의 투과 특성을 RCWA(Rigorous coupled-wave analysis)방법에 의한 Transfer matrix로 해석하였다. Square lattice의 PBG 구조에 대하여 TE 편파에서 유전율의 변화와 결함(defect)의 유무에 대한 투과 특성을 고찰하였다.

• Journal of information and communication convergence engineering
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• 제14권3호
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• pp.184-190
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• 2016

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.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.413-422
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• 2002

A novel photonic bandgap(PBG) structure is proposed and measured for wide bandgap and compact circuit applications. The proposed structure realizes the ultra-wideband bandgap(2-octave) characteristics by superposing two different PBG structures into a coupled double-plane configuration. A low pass filter fabricated using 3-period of the PBG cells shows 2-octave 10 ㏈ stopband from 4.3 to 16.2 ㎓ and 0.2 ㏈ insertion loss in the passband. Moreover, we confirmed that 44∼70 % size reduction can be achieved using the proposed PBG structures. We expect this novel double-plane PBG structure is widely used for compact and wideband circuit applications, such as compact high-efficiency power amplifiers using harmonic tuning techniques.

• ETRI Journal
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• 제35권5호
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• pp.827-837
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• 2013

In this paper, we present wideband common-mode (CM) noise suppression using a vertical stepped impedance electromagnetic bandgap (VSI-EBG) structure for high-speed differential signals in multilayer printed circuit boards. This technique is an original design that enables us to apply the VSI-EBG structure to differential signals without sacrificing the differential characteristics. In addition, the analytical dispersion equations for the bandgap prediction of the CM propagation in the VSIEBG structure are extracted, and the closed-form expressions for the bandgap cutoff frequencies are derived. Based on the dispersion equations, the effects of the impedance ratio, the EBG patch length, and via inductances on the bandgap of the VSI-EBG structure for differential signals are thoroughly examined. The proposed dispersion equations are verified through agreement with the full-wave simulation results. It is experimentally demonstrated that the proposed VSI-EBG structure for differential signaling suppresses the CM noise in the wideband frequency range without degrading the differential characteristics.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2007년도 제6회 추계학술대회 및 정기총회
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• pp.334-337
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• 2007

• 한국전자파학회논문지
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• 제18권2호
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• pp.199-205
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• 2007

본 논문에서는 초고속 디지털 PCB 회로에서 발생하는 GBN(Ground Bounce Noise)을 억제하기 위한 새로운 EBG(Electromagnetic Bandgap) 구조의 전원면을 제안하였다. 제안된 구조는 육각형 모양의 단위 셀과 각 셀을 연결하는 선로로 구성되어 있다. 육각형 모양의 단위 셀은 등방성을 띄어 인접 셀의 각 포트 사이의 전달 특성을 동일하게 한다. 제안된 구조는 실제 제작, 측정되었고 330 MHz부터 5.6 GHz까지 넓은 주파수 대역에서 -30 dB 이하로 GBN을 억제하는 특성을 나타낸다. Electromagnetic Interference(EMI) 방사 측정 시에도 일반 전원면/접지면에 비해 낮은 EMI 특성을 나타낸다. 본 논문에서 제안한 육각형 EBG 구조의 전원면은 실제 EBG 전원면의 적용에 효율적으로 작용하여 초고속 디지털 회로의 EMI 문제를 해결하는 데 기여할 것으로 기대된다.