• Journal of information and communication convergence engineering
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• v.14 no.4
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• pp.252-257
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• 2016

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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.306-313
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• 2012

In order to enhance the isolation level between two dual-band E-slot microstrip patch antennas, EBG structure which operates in UMTS Tx(1.92~1.98 GHz) and Rx(2.11~2.17 GHz) band is proposed. The proposed EBG structure made with a periodic array of two different size EBG unit cells which has a modified mushroom-type for isolation improvement between two antennas. They do not share a common ground plane of the microstrip patch antenna. Overall size of the fabricated antenna is $210.5mm{\times}117mm$. The two different EBG unit cell sizes are $15.6mm{\times}4mm$ and $17.4mm{\times}4mm$, respectively. It was etched on the FR-4 substrate(thickness=3.93 mm, ${\varepsilon}_r$=4.6). The experiment results show that the isolation level between antennas in Tx/Rx band were improved by about 9 dB and 12 dB, respectively, through the use of the proposed EBG structure.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.3 s.94
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• pp.300-310
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• 2005

In this paper we propose the compact three-layer EBG structure. The unit cell of the proposed EBG structure is composed of a square patch in the upper layer and a square ring stripline in the lower layer that are connected to the ground plane through conducting vias. Reflection phase analysis method and tangential transmission method were considered to accomplish effective EM simulation and measurement. EM simulation results indicate that bandgap characteristics of the EBG structure using both methods is nearly identical. Parametric studies have been performed with the EM simulator to analyze the properties of the EBG structure by investigating the phase shift of the normally incident plane wave, and the transmission measurements between simple monopole antennas positioned near the EBGstructure have been done. The operating fiefuency bandgap of the proposed EBG structure is about 34 $\%$ lower than the conventional EBG structure with the same size. Measured results show bandgap from 0.930 GHz to 0.945 GHz.

• ETRI Journal
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• v.35 no.5
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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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.78-81
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• 2015

This paper investigates the performance of phone case with different permittivities like plastic, urethane and silicone. Then, we put an electromagnetic band gap (EBG) structure in phone case to reduce the specific absorption rate (SAR). In order to design the phone case, a loop antenna for PCS 1900 band was used. The phone case consists of a hairpin-like EBG structure that is more compact than other EBG structures. The SEMCAD X fdtd simulation results showed that, this proposed phone case can reduce SAR by 13 - 30% at similar power that is radiated by the antenna. This phone case can be used in future to reduce the SAR from mobile phones.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.786-795
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• 2010

In this paper, we propose a new EBG structure that the two unit cells are connected by the bridge line in signal transmission plane. The SSN of the power plane is reduced effectively by via holes and bridge lines connecting the unit cells. The superior signal transfer characteristic is shown between the signal lines in the signal transmission plane. The proposed EBG structure contains 1.2 GHz cut-off frequency and less than －30 dB suppression in the 8.3 GHz broad bandwidth. In addition, To improve the SI(Signal Integrity) in signal transmission plane keeping the same bandstop frequency range, the optimized location of the reference plane is proposed.

• Journal of Satellite, Information and Communications
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• v.9 no.4
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• pp.42-46
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• 2014

In this paper, a coil typed electromagnetic band gap (EBG) structure to be inserted in the printed circuit board (PCB) inner layer in order to stabilize the PCB power line is proposed and implemented for global-navigation satellite service (GNSS) with the bandwidth from 1.55GHz to 1.81GHz. From the measurement result of the PCB board including EBG structure, the insertion loss(S21) was measured below about -50dB. From these results, it is expected that the stabilization of power delivery network (PDN) structure in the PCB circuit design should be improved and the preparation to EMI will be effective.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.504-506
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• 2008

전기전자 장치 내부의 PCB에 존재하는 전력공급/접지판은 RF 공진잡음을 발생시켜 디지틀 신호 품질 저하 및 불요방사의 문제를 일으킨다. 본 논문에서는, 전력공급/접지판의 RF 잡음을 제거하기 위한 방법으로 Mush-room EBG 구조를 사용할 때 이 구조가 가지는 전자기 및 전기적 특성을 모드해석법과 회로이론의 하이브리드화를 통해 예측을 수행한다. 예측을 통해 잡음을 억제할 수 있는 유용한 정보를 얻는다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.101-106
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• 2005

This paper presents a new microwave oscillator incorporating a corrugated coplanar waveguide (CCPW) electromagnetic bandgap (EBG) structure as its terminating resonance component. The use of a compact CCPW EBG structure was effective in reducing the phase noise and improving the harmonic characteristics of the microwave oscillator circuit without additional backside processing and drastic size increment. The fully planar CCPW oscillator oscillating at the frequency of 5.41 GHz showed a phase noise characteristic of -90.7 dBc/Hz at 100kHz offset and a second harmonic suppression of 42.67 dB.

• Journal of information and communication convergence engineering
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• v.16 no.3
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• pp.197-202
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• 2018

This paper reveals the impact of the insertion of electromagnetic band gap (EBG) structures on the performance of circularly polarized (CP) patch-slot antenna with offset slot. Several optimizations are necessary to precise physical parameters in the aim to fix the resonance frequency at 3.2 GHz. The proposed antenna possesses lightweight, simplicity, low cost, and circular polarization ensured by two feeding sources to permit right-hand and left-hand circular polarization process (RHCP and LHCP). The measured results compared with simulation results of the proposed circularly polarized EBG antenna with offset slot show good band operations with –10 dB impedance bandwidths of 9.1% and 36.2% centered at 3.2 GHz, which cover weather radar, surface ship radar, and some communications satellites bands. Our investigation will confirm the simulation and experimental results of the EBG antenna involving new EBG structures.