• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1086-1098
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• 2005

Two types of small wideband antennas are proposed for UWB application. One type is small biconical structure fed by coaxial probe, which is easy to be installed on the circuit board. The other type is of planar bow-tie type fed by coplanar transmission line. Generally, the bandwidth of the latter type is significantly narrower than that of the former type. It is shown, however that the bandwidth of the latter type can be made to be comparable to that of the former, if some series inductive component is introduced in the center conductor line in the CPW transmission line by replacing some part of center line with narrower line of higher characteristic impedance. The series inductance component play an important role of neutralizing the capacitive component of the small bow-tie antenna, thereby making broadband impedance matching possible. The small planar bow-tie antenna was fabricated and experimented. The experimental results for return loss are observed to be in good agreement with simulated results. The radiation pattern is also investigated experimentally.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.421-424
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• 2005

X-ray is currently most effective method in detecting small malignant breast tumors but has the several problems due to suppressing breast, ionizing radiation and not detecting small cancer. In this paper, a new method is proposed by using dielectric characteristics of pathological tissues and time delay of backscattered response. We have developed a detection algorithm and verified it by numerical simulation and measurement for a prototype system. For a prototype system, we have fabricated experimental model(artificial breast with a cancer) and UWB(ultra-wideband) antenna. The results of the measurement simulation show an excellent detection capability of a cancer tissue. It is found that a good UWB antenna is a key element of such detection system. Further study is ongoing to develop a commercial system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.11
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• pp.1980-1985
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• 2010

This paper is about design of optimal structure of slot antenna array antenna with inner waveguide in accordance with the slot model, and fabrication of its prototype sample operating at the frequency of 24 GHz. Results of this work can be employed as a useful tool to develop and diversify slot antenna having superior performance and omni-directivity to that of current antenna. The implemented antenna demonstrates ultra-wideband performance for frequency ranges 24 GHz with the relatively high and flat antenna gain of 18.64dBi and low sidelobe levels. In addition, a $2{\times}8$ antenna array for phased-array systems and mm-wave sensor applications is also presented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.449-452
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• 2009

In this paper, we propose a ultra-wideband(UWB) antenna for UWB applications. The proposed antenna is designed to operate from 3.1GHz to 11.2GHz. It consists of a rectangular patch with two steps, a single slot on the patch, obtained to decrease the back radiation by a partial ground plane. Details of the proposed antenna design and measured results are presented and discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.7
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• pp.1221-1228
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• 2016

In this paper, we propose a modified rhombus slot UWB(Ultra Wide Band) antenna with fork-shaped feeding structure. The proposed antenna is modified rhombus slot structure and fork-shaped feeding structure to get ultra-wideband characteristics for UWB communication. Modified rhombus slot structure consists of slot shaped which eliminated upper and lower part of the basic rhombus slot. The antenna is designed on an FR-4 substrate of which the dielectric constant is 4.4, and its overall size is $34mm(W_1){\times}34mm(L_1){\times}1mm(t)$, and its slot antenna size is $30mm(W_2){\times}16.75mm(L_3+L_4)$. After carrying out the simulation of each parameters, optimized values are obtained. From the fabricated and measured results, return loss of the proposed antenna satisfied Return Loss -10dB in 3.1 ~ 10.6 GHz. And measured results of gain and radiation patterns characteristics displayed for operating bands.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2518-2525
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• 2015

In this paper, we propose a UWB(Ultra Wide Band) antenna with CPW(Coplanar Waveguide) structure notched the 802.11a(5.15 ~ 5.825 GHz) band by using the U shaped slot. The proposed antenna not only shows Ultra-Wideband characteristic(3.1 ~ 10.6 GHz) suitable for UWB communications but has partially notched-band characteristic to reject 5 GHz WLAN band(5.15 ~ 5.825 GHz). The antenna is designed on an FR-4 substrate of which the dielectric constant is 4.4, and its overall size is $30mm(W){\times}20mm(L){\times}1mm(t)$. Fabricated antenna satisfied $VSWR{\leq}2$ in 3.1 ~ 10.6 GHz except for the band rejection of 5.15 ~ 5.825 GHz. And measured results of gain and radiation patterns characteristics displayed determined for operating bands.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.194-198
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• 2005

A novel ultra wideband microstrip-fed circular patch antenna having band stop characteristic in UNII band is presented. The band stop characteristic is realized by inverted-U shaped slot. The range of stop bandwidth can be adjusted by changing the length of the slot. The measured impedance bandwidth of the proposed antenna is from 2.9 GHz to 12.1 GHz with the stop band from 4.9 GHz to 6 GHz for VSWR<2. This antenna shows a monopole-like radiation pattern and flat gain characteristic throughout the operating frequency band.

• ETRI Journal
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• v.34 no.5
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• pp.674-683
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• 2012

We propose a slot antenna consisting of a rectangular slot on the ground plane, fed by a microstrip line with a rectangular-ring-shaped tuning stub that can be deployed in ultra-wideband (UWB) communication systems to avoid interference with wireless local area network (WLAN) communication. Our antenna can achieve a single band-notched property from the 5 GHz frequency to the 6 GHz frequency owing to a controllable band notch that uses L- and J-shaped parasitic elements. The antenna characteristics can be modified to tune the band-notched property (4 GHz to 5 GHz or 6 GHz to 7 GHz) and the bandwidth of the band notch (1 GHz to 2 GHz). Furthermore, the shifted notch with enhanced width of the band notch from 1 GHz to 1.5 GHz is described in this paper. The UWB slot antenna and L- and J-shaped parasitic elements also provide the band-rejection function for reference in the WiMAX (3.5 GHz) and WLAN (5 GHz to 6 GHz) regions of the spectrum. Experiment results evidence the return loss performance, radiation patterns, and antenna gains at different operational frequencies.

• Journal of electromagnetic engineering and science
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• v.17 no.1
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• pp.44-49
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• 2017

A compact planar microstrip-fed ultra-wideband (UWB) antenna with a dual band-notched for UWB application is presented and analyzed. By inserting a U-shaped slot and inverted U-shaped slot into the pot-shaped radiator, two notched bands are achieved. By optimizing the width and length of the U-shaped slots and inverted U-shaped slot, a desired bandwidth of voltage standing wave ratio (VSWR) less than 2.0 can be achieved, ranging from UWB bands with notched dual bands. The proposed antenna is fabricated on an inexpensive FR-4 substrate with overall dimensions of $28.0mm{\times}39.5mm$. The measured results confirm that the proposed antenna covers from 1.775 to over 13.075 GHz with two rejection bands of around 3.325-3.925 GHz and 5.3125-6.025 GHz. In addition, the proposed antenna showed good radiation characteristics and gains in the UWB bands.

• ETRI Journal
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• v.46 no.2
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• pp.218-226
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• 2024

This paper presents a novel circular fractal ring monopole antenna for ultra-wideband (UWB) hardware with dual band-notched properties. The proposed antenna consists of four crescent-shaped nested rings, a tapered feeding line at the front of the dielectric material, and a semicircular ground plane on the backside. In this design, the nested rings are used both as a radiation element and a band rejection element. The proposed antenna has a bandwidth of 9.03 GHz, which works efficiently in the range of 2.63 GHz-11.66 GHz with the dual notched bands of Worldwide Interoperability for Microwave Access (WiMAX) at 3.15 GHz-3.66 GHz and wireless local area network (WLAN) at 4.9 GHz-5.9 GHz, respectively. The antenna has a compact size of 20 mm × 30 mm × 1 mm (0.177 × 0.265 × 0.0084 λ0) and is implemented using a flame-retardant type 4 (FR4) material. It has a maximum gain of approximately 4 dB in its operating range, and experimental results support the simulation predictions with high accuracy. The findings of this study imply that the designed antenna can be utilized in UWB applications.