• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.12 s.115
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• pp.1199-1205
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• 2006

This paper proposes a wideband monopole antenna with improved band rejection characteristics by inserting two band notch slots with half wavelength in radiator. The designed antenna is composed of bow-tie patch fed electromagnetically with parasitic ground patch of a semicircular shape. We obtained band rejection filter-like characteristics by controlling coupling amounts between two horizontal resonance slots. Using this technique, we achieved the broad rejection bandwidth and improved skirt characteristics compared with only one notch slot. The measured bandwidth is from 2.7 GHz to 6.9 GHz for VSWR below 2.0 except the limited band of $4.96{\sim}5.51GHz$. This antenna shows a similar radiation pattern of the ideal monopole and the radiation gain reduction is more than $5{\sim}10dB$ on the x-z plane at rejection frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.516-521
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• 2011

In this paper, an inverted-triangle patch UWB antenna with an uneven ground planes and an inverted T-slot for 5 GHz WLAN band rejection is presented. The operating bandwidth of the proposed antenna fed with the CPW line is expanded from 3.1 GHz to 10.6 GHz for about -10 dB return loss using three angular parameters correlated to the main patch and the ground plane. The fabricated antenna on Taconic RF-60A substrate with 6.16 relative dielectric constant and 0.64 mm thickness has a main antenna patch size of 36 mm${\times}$19.5 mm. The measured results show return losses of about -10 dB and nearly omni-directional radiation patterns. The proposed UWB antenna has advantages of easily adjustable impedance characteristics by the three angular parameters and easily accomplishable band rejection characteristics by the inverted T-slot.

• Journal of Advanced Navigation Technology
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• v.16 no.5
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• pp.766-772
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• 2012

In the present study, wideband microstrip monopole slot antennas which can be applied to the RF4CE Zigbee remote controller are designed. First I-shaped monopole slot antenna which has ${\lambda}g/4$ length at 2.45GHz is designed. In particular, a conducting via is used to connect the microstrip feed line and the ground plane surrounded with the etched slot for the bandwidth improvement. In order to reduce the antenna size, it is changed into L-shaped and T-shaped monopole slot antennas for which improve results of antenna performance are observed. In case of T-shaped monopole slot antenna, impedance bandwidth(VSWR<2) is about 3.32GHz, and also its radiation efficiency and gain is more than 90% and 2.1dBi respectively at whole operating frequency range. In particular, all of proposed monopole slot antennas have the end-fire radiations which has a maximum radiation power toward direction of open ends of monopole slots.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.11
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• pp.1127-1133
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• 2003

In this paper, we proposed a novel folded multi-strip monopole antenna whose height is reduced using folded strip structure. It has a broadband characteristic and its measured impedance bandwidth ratio is approximately 1.85 : 1, from 4.55 GHz to 8.4 GHz, for VSWR$\leq$2. Proposed antenna has vertically polarized omni-directional conical beam radiation pattern. It maintains about the same radiation pattern over entire bandwidth.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.739-741
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• 2014

We suggested the new compact dual band monopole antenna using two crossed planar monopole antenna. The proposed antenna will be used for the ISM dual band 2.45GHz/5.8GHz. It is necessary to verify its performance through the follow-up development of the proposed antenna for the high-speed wireless actual communications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.11
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• pp.1225-1232
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• 2009

In this paper, a parabolic edge planar monopole antenna for indoor DTV reception is presented. The antenna has broadband property with the planar monopole and ground of parabolic edges. It is designed close to self-complementary structure as changing curvature of edges of monopole and ground. Monopole and ground conductors of the antenna are on the same plane, and excited through CPW feeding. It is fabricated on an FR4 dielectric substrate of $\varepsilon_r=4.4$, and the dimension is $40\;mm{\times}200\;mm{\times}1.6\;mm$. Return loss is larger than 10 dB in 470~806 MHz. Maximum gain is 1.86 dBi on E-plane at 810 MHz and 3.86 dBi on H-plane at 600 MHz.

• Journal of Broadcast Engineering
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• v.23 no.6
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• pp.925-930
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• 2018

In this paper, we present a low profile dual-microstripline-fed double 4-arrayed meander monopole antenna with a cross-type element back by separated four-segments mesh-type reflector. The cross-type element and separated four-segments mesh-type reflector leads to enhance radiation patterns and antenna gain characteristics. The measurement value of the proposed antenna show that it has dipole-like radiation pattern characteristics. The experimental peak gain of fabricated antenna is about 2.89 dBi, which presents relatively high gain characteristics for a low profile(small-size) one. This antenna can be applied mobile RFID(radio frequency identification) readers, small medical instruments, broadcasting and home-networking operations, and other low profile high-gain systems.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.24-30
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• 2010

In this paper, a novel electrically small monopole type resonant antenna is proposed. The very short length monopole (${\iota}{\approx}{\lambda}_g/15$ ) acts as a capacitive element and the slot on the ground structure acts as an inductive element, hence the combined system with these two elements thus form an LC resonator. The equivalent circuit model of the antenna structure was used to analysis and qualify the design correctness. Although the proposed antenna has very small size, it shows good performances. The measured maximum gain and radiation efficiency of the fabricated antenna at the frequency of 2.1 GHz was 3.6 dBi and 77.8 %, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.11
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• pp.1669-1676
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• 1993

In this paper, a thin-straight monopole antenna attached to a conducting box is analyzed using a moment method with the pocklington integral expression for the exact Green's function. A modeling of a conducting box is based on a Wire-Grid method for an efficient calculation procedure. A system of linear equation is obtained using the piecewise sinusoidal basis function. And a Junction basis function is enforcing to represent the physical current on the edge of the conducting box. Especially, the junction basis functions are overlapped for the current continuity preserving on the vertexes. Numerical results are obtained for the current distribution on the unified antenna/conducting box system, input impedance and radiation pattern. The results are compared with the known data.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.7
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• pp.763-768
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• 2015

In this paper, a microstrip patch antenna with arrow and ribbon shape for WLAN was designed and manufactured. The antenna was designed on a FR-4 substrate that has a thickness of 0.8mm and a dielectric constant of 4.4. The substrate size is $50{\times}40mm^2$. A commercially available tool was used for simulation to get the optimized parameters and the optimized values were obtained by finding the parameters that act sensitively to the performance of the antenna. The proposed antenna was produced using the optimized values, and characteristics of return loss, gain and radiation pattern in WLAN bands were measured.