• 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.199-203
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• 2005

In this paper, a novel compact and frequency band-notch antenna for Ultra-Wideband(UWB) applications is proposed. The designed antenna not only shows good impedance bandwidth for ultra-wideband but has band notch characteristic for the frequency band of $5.15\~5.825\;GHz$ limited by IEEE 802.1la and HIPERLAN/2. To achieve both properties of wide band and band notch, the techniques of a concaved ground plane and inserted U-shaped thin slot into planar radiator are used respectively. A manufactured antenna satisfied VSWR<2 for the frequency band of $2.95\~11.7\GHz$ except the limited band of $4.92\~5.866\;GHz$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.207-213
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• 2008

A simplified design procedure for quasi-Yagi antenna arrays using an ultra-wideband balun is presented. The proposed antenna design procedure is based on the simple impedance matching among antenna components: i.e., balun, feed, and antenna This new broadband and high gain antenna array is possible due to the ultra-wideband performance of the balun. As design examples, wideband $1\times4$ and $1\times8$ quasi-Yagi antenna arrays are successfully designed and implemented in Ku-band with frequency bandwidths of about 50 % and antenna gains of 9$\sim$10 dBi and 11$\sim$12 dBi, respectively. And the simulated and measured results demonstrate wide bandwidths and good radiation properties. These antenna arrays can be applied to various phased-array and spatial power combining systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.3
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• pp.257-267
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• 2015

This paper presents a ultra-wideband sinuous antenna that operates in a whole frequency range (0.824~5.85 GHz) of Cellular/GSM-800, GSM900, ISM, GPS, DCS/GSM1800, PCS/GSM1900, WCDMA/UMTS/IMT2000, WiBro, WLAN and WiMax. The proposed antenna, which is composed of two sinuous arms, is designed as a self-complementary structure in order to have frequency-independent characteristics. It also uses a wideband balun of Klopfenstein taper structure to match to $50{\Omega}$. Experimental results show that the -10 dB return loss bandwidth of the proposed antenna is 5.24 GHz that ranges from 0.76 to 6 GHz, which covers all the frequency bands of the various wireless services. Within the entire operating frequency range, the measured radiation patterns in both E-plane and H-plane show nearly constant bidirectional broadside beams and the maximum antenna gain is measured to fall between 2.32~6.01 dBi.

• ETRI Journal
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• v.32 no.1
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• pp.62-67
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• 2010

In this paper, an ultra-wideband internal antenna for use in mobile applications is proposed. The proposed antenna has symmetrical bi-arm structures printed on the top and bottom of the substrate, and it occupies a compact area of 10 mm ${\times}$ 10 mm ${\times}$ 1 mm. The designed antenna has an impedance bandwidth from 3 GHz to 12 GHz and near omnidirectional radiation patterns over the frequency band of interest. The group delay between two antennas fabricated using the proposed design is less than 0.8 ns, and the maximum gain variation is about 3.16 dB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1642-1648
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• 2017

Ultra-wideband antennas are desired for several applications including satellite communications, radars, remote sensing system, telescopes, and microwave imaging systems. There are many types of wideband antenna structures, but the tapered slot Vivaldi antenna is advantageous in terms of cost, weight, scan angle capabilities, end-fire radiation, and ease of feeding and system integration. In this paper, a modified antipodal Vivaldi antenna is presented. A novel AVA with H-shaped parasitic patches has the capacity to improve the radiation characteristics in the whole operation frequencies. A prototype of the modified antenna with RT/duroid 5880 substrate of a relative dielectric constant (${\epsilon}_r$) of 2.2, and a thickness of 31mil is fabricated and experimentally studied as well. It measures a ${\mid}S_{11}{\mid}$ of less than -10dB and gain of 9-12dBi over 7.8-52.5GHz which shows reasonable agreement with the simulated one.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.9 s.100
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• pp.941-948
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• 2005

In this paper, we have proposed a Ultra-Wideband slot notch antenna by using a semi-circular extension. The proposed antenna cover the entire UWB band(3.1${\~}$10.6 GHz) and notch out the IEEE 802.1la frequency band(5.15${\~}$5.825 GHz) by inserting a $\lambda$/4 length slot into the patch. A prototype antenna was fabricated on FR-4( ${\epsilon}_r$ =4.4, substrate thickness=0.8 mm) and measured for VSWR characteristics. The measured notched frequency variations versus frequency for different slot length. The path loss and group delay were measured. The proposed antenna also show a good gain flatness(1.9 dBi) except the IEEE 802.1la frequency band.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.33-37
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• 2009

In this paper, a printed small Ultra-Wideband (UWB) antenna with directive radiation characteristics based on combination of electric-magnetic radiators is presented. The combinations of the electric and magnetic type antennas result in the directive radiation patterns for all observed UWB frequency band. Simple combination of dipole antenna and loop antenna is also presented to show that proper configuration of electric radiator and magnetic radiator can produces directive radiation characteristics. The target frequency is from 3.1 GHz to 10.6 GHz with size of $15\;mm{\times}31\;mm$. A proto-type of the combined antenna is simulated, fabricated and measured. Simulation and experimental results of input impedance and gain characteristics of the proposed antenna are presented. There are good agreements between the simulated and measured VSWR curves. Also, the results show the directive radiation characteristics with small antenna form factor over the target frequency range.

• 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.235-245
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• 2005

In this paper, a novel Ultra-Wideband(UWB) antenna fed by CPW is designed, fabricated, and measured for UWB communications. We have used the Microwave Studio of CST to simulate the proposed antenna. It is designed to work on a substrate TMM4 of thickness 0.762 mm and relative permittivity 4.5. The proposed antenna is satisfied with Ultra-Wideband communication band from 3.1 GHz to 11.5 GHz, for VSWR$\leq$2, and isolated IEEE 802.1la frequency band(5.15 GHz$\~$5.825 GHz) using a rectangular slot. Measured group delay variation is less than 1 ns, thus indicating the proposed antenna a good candidate for UWB applications.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.109-112
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• 2011

In this paper, we proposed a planar reversed triangle monopole antenna for UWB(Ultra Wideband) communication. RF-60A substrate of 0.64 mm thickness and 6.15 relative permitivity and 0.035 mm conductor of thickness and loss tangent 0.0025 is used for implementation. We have used Ansoft $HFSS^{TM}$(High Frequency Structure Simulator) to simulate the proposed antenna. The proposed antenna showed return losses about -10 dB, nearly omni-directional radiation patterns and maximum gains are over -5 dBi at the frequency band from 3.1 GHz to 10.6 GHz for ultra wide band communication.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.83-89
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• 2020

A microstrip feedline based open ended folded-slot antenna is proposed for ultra-wideband (UWB) applications. The prototype of the proposed antenna is fabricated on the FR4 dielectric substrate. The proposed antenna has a wide n-shaped slot that is useful for designing circuit components on the same printed circuit board (PCB) as that of the radio frequency (RF) modules. The proposed antenna use two kinds of slots as radiators, and each slots have different characteristics because of the different type of ends of the slot. The wideband characteristic can be obtained by resonances of each slot which are occurred at different frequencies. The measured impedance bandwidth (S₁₁≤ -10 dB) is 2.9-11.56 GHz, and the antenna peak gain is 2-4 dBi over the UWB range. The antenna has a stable omni-directional radiation pattern and only a small group-delay variation across the UWB passband. In addition, we present a modified design with band-notched characteristics of a 5 GHz wireless local area network (WLAN) frequency band.