• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.12
• /
• pp.1272-1278
• /
• 2009

The cancellation method of P/G(power/ground) plane resonances which are generated between the power plane and the ground plane in a 4-layer PCB(Printed Circuit Boards) with a via-hole for the improvement of the RE(Radiated Emission) characteristic is presented. The validity of the proposed method was confirmed from simulation and measurement of performances of signal transmission characteristic, intensities of edge-radiation and radiated emission of PCB with a via-hole.

• 한국초전도학회:학술대회논문집
• /
• v.10
• /
• pp.189-192
• /
• 2000

We fabricated rapid single-flux-quantum RS flip-flop circuits with and without Y$_1$Ba$_2$Cu$_3$O$_{7-{\delta}}$(YBCO) ground plane. The circuit consists of SNS-type ramp-edge Josephson junctions that have cobalt-doped YBCO and Sr$_2$AITaO$_6$(SAT) for barrier layer and insulator layer, respectively. The fabricated Josephson junction showed a typical RSJ-like current-voltage(I-V) characteristics above 50K. We sucessfuly demonstrated RS flip-flop at temperatures around 50K. The RS flip-flop fabricated on ground plane showed more definite set and reset state in voltage-flux(V-${\phi}$) modulation curve for read SQUID, which may be attributed to a shielding effect of the YBCO ground plane.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.4
• /
• pp.815-820
• /
• 2007

In this paper, a small internal antenna for dual-band(RFID, PCS) applications is presented. The proposed antenna is a basic PIFA type and has a deformed ground plane under the main radiator. The modified ground plane is spreading the surface current and the antenna miniaturization can be achieved due to the coupling effect. The antenna is manufactured according to the simulation results and the resonance frequency move to low frequency band by 150MHz. And the surface current on the radiator and ground plane is evenly distributed so our suggested antenna can be used for better SAR and HAC performance.

• Journal of electromagnetic engineering and science
• /
• v.19 no.1
• /
• pp.1-5
• /
• 2019

In this study, optimum locations for a loop-type ground radiation antenna are evaluated for C-shaped ground planes of two different sizes. To achieve good radiation performance, the antenna needs to be located such that it couples with the dominant current mode of the ground plane. Antenna locations are proposed using the characteristic mode analysis of the ground planes. The measured bandwidths of the antennas at the proposed locations have more than twice the bandwidths of the cases in which the antennas are coupled with non-dominant modes. The operating frequency of the antennas is 2.45 GHz.

• Proceedings of the IEEK Conference
• /
• 1999.06a
• /
• pp.385-388
• /
• 1999

A new frequency-variant equivalent circuit model of power/ground plane is presented. The equivalent circuit is modeled with grid cells. The circuit parameters of each cell were extracted by using Fasthenry. To verify the developed circuit model, its s-parameters are compared with the measured s-parameters 〔2〕 and the full-wave simulation-based s-parameters. Consequently, it is shown that our frequency-variant equivalent circuit model can accurately predict imperfect ground effects under the high frequency operation of electronic package.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.6 s.97
• /
• pp.632-643
• /
• 2005

This paper presents a folded stripline-fed small broadband disk-loaded monopole antenna with vertical ground plane. The bandwidth of the proposed antenna can be enhanced by electromagnetic coupling between the shorted rectangular disk and the probe with folded strip line. The measured impedance bandwidth of the proposed antenna is $37.6\%$ for $VSWR\leq2$ with the center frequency at 2.313 GHz and has the physical dimensions of only $11mm\times11mm\times11mm$ which corresponds to the electrical length of $0.085\lambda_0\times0.085\lambda_0\times0.085\lambda_0$. For improving the radiation pattern characteristics, rectangular slits are inserted in the vertical ground plane. Rectangular slits affect the currents distribution on the ground plane, so that the antenna radiation in the direction of the ground plane is reduced more than 3 dBi. Gain of the antenna is approximately 2.6 dBi within the bandwidth.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.28 no.4
• /
• pp.251-260
• /
• 2017

This paper describes the design of a slit on ground plane to improve the axial ratio of the spiral antenna for the NLJD system application. A proposed slit shape located on the ground plane is changed to compare with the archimedean spiral slit shape of the antenna in reference [7]. In order to improve the axial ratio, the slit on the ground plane is divided by the uniform angle and the conductor of position where the current has the opposite direction each other is eliminated. Measured return loss, radiation pattern and gain show a good agreement with the computer simulation results. Even though the proposed slit structure on the ground plane was changed to compare with ones of reference [7], the characteristics such as return loss, radiation pattern and gain are not almost changed and only the axial ratio was remarkably improved at 4.88 GHz.

• Journal of Advanced Navigation Technology
• /
• v.22 no.5
• /
• pp.436-441
• /
• 2018

In this paper, a design method for a compact double dipole quasi-Yagi antenna with a V-shaped ground plane operating in dual bands including 2.45 GHz and 5 GHz wireless LAN frequency bands is studied. First, a quasi-Yagi antenna operating in the 2.45 GHz band is designed, and a V-shaped ground plane is used instead of a conventional strip ground plane to reduce the length of the antenna. A second dipole is connected to the dipole driver of the quasi-Yagi antenna for 2.45 GHz band and a director is appended for 5 GHz band operation. A prototype of the proposed dual-band antenna operating at 2.45 GHz WLAN band and 4.57-7.11 GHz band is fabricated on an FR4 substrate with a dimension of 40 mm by 55 mm. Fabricated antenna shows frequency bands of 2.33-2.75 GHz and 4.38-7.5 GHz for a voltage standing wave ratio less than 2. Measured gain remains more than 4 dBi in both bands.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.9 no.5
• /
• pp.648-658
• /
• 1998

In this paper, the effect of the gap in the ground plane on the electromagnetic interference (EMI) is analyzed quantitatively. Because of a lot of advantages compared to other numerical techniques, the FDTD (finite difference time domain) is applied to the EMI effect modeling. The analyzed model is the simplified PCB (printed circuit board) which has a microstrip and ground plane. The inductance induced by the gap is modeled and calculated by gridding the whole PCB based on the FDTD algorithm. When external cables are attached to the PCB, the common-mode current is induced along the attached cable and the resulting electric field strength is calculated and presented along with the FCC and CISPR EMI limits. The results show that the radiated field strength highly depends on the size of the ground plane gap. The numerical simulation results can be used as a reference in the practical PCB design with the ground plane gap.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.7 s.349
• /
• pp.156-161
• /
• 2006

In this paper, an E-patch antenna on the U-shaped ground plane is designed and experimental studied. In order to reduce to cross-polarization level and to enhance the gain of the microstrip patch antenna, a U-shaped ground plane is employed in the microstrip patch antenna. As a main radiator, an E-shaped patch is used to reduce the antenna size as small as possible. Also to enhance the bandwidth of the antenna, a substrate of the lowest permittivity of which thickness as thick as possible is used and a rectangular patch is overlaid on the air substrate of the E-shaped patch antenna. The radiation characteristics of the antenna are calculated by CST Microwave Studio 5.0 simulation software. Experimental results show that by increasing the height of the sidewall of the ground plane, the antenna gain is increased and the cross-polarization level is decreased.