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Author

Ki-Hak Kim

Bio: Ki-Hak Kim is an academic researcher from Information and Communications University. The author has contributed to research in topics: Monopole antenna & Antenna measurement. The author has an hindex of 5, co-authored 5 publications receiving 582 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, a novel ultra-wideband antenna with band elimination characteristic is presented, which has omnidirectional patterns in the E-plane and impedance bandwidth of about 3-18 GHz with VSWR below 2.
Abstract: A novel ultra-wideband antenna with band elimination characteristic is presented, which has omnidirectional patterns in the E-plane and impedance bandwidth of about 3-18 GHz with VSWR below 2. The proposed antenna is fed by microstrip line, and consists of the monopole type with two parasitism-patches rejecting 5.15-5.825 GHz bandlimited by IEEE 802.11a and HIPERLAN/2.

307 citations

Journal ArticleDOI
TL;DR: In this paper, a band-rejected ultrawideband antenna with one parasitic strip is presented, which is designed to work on a substrate FR4 that has a thickness of 1 mm and relative permittivity of 4.6.
Abstract: A novel band-rejected ultrawideband antenna with one parasitic strip is presented in this paper. It is designed to work on a substrate FR4 that has a thickness of 1 mm and relative permittivity of 4.6, and to operate from 3 to 17 GHz. The proposed antenna is fed by microstrip line and utilizes the parasitic strip to reject the frequency band (5.15-5.825 GHz) limited by IEEE 802.11a and HIPERLAN/2. The size of the antenna is 20/spl times/20 mm/sup 2/ and this antenna has good radiation characteristics. Effects of varying the location and length of the parasitic strip and the structure of the ground and monopole patch on the antenna performance have also been studied.

188 citations

Journal ArticleDOI
TL;DR: In this article, a double discone antenna is composed of the asymmetric biconical antenna and the inverted-discone antenna, which exhibits a 1:100 impedance bandwidth (180 MHz-18 GHz) with VSWR below 2.5.
Abstract: A novel double discone antenna is composed of the asymmetric biconical antenna and upside-down discone antenna. The asymmetric biconical antenna has all-wire structure like octopus legs for covering at lower operating frequency, and the upside-down discone antenna has conical shape playing a role as covering at higher operating frequency. An elaborate assembly of two antenna exhibits a 1:100 impedance bandwidth (180 MHz-18 GHz) with VSWR below 2.5 while maintaining an acceptable omnidirectional radiation pattern except at about 12 GHz region. The simulated performances of the proposed antenna are verified by the measured results of the fabricated antenna. There seems to be good agreement with each other. These features make such antennas highly suitable for application to UWB system.

54 citations

Journal ArticleDOI
TL;DR: In this paper, a ring-shaped parasitic patch was used to reject the frequency band (5.15-5.825 GHz) limited by IEEE 802.11a and HIPERLAN/2.
Abstract: A novel UWB antenna with band-elimination characteristic is presented. The proposed antenna is fed by microstrip line and consists of an inversed bell-shape radiation patch, rounded ground, and a ring-shaped parasitic patch. The proposed antenna utilizes a ring-shape parasitic patch to reject the frequency band (5.15–5.825 GHz) limited by IEEE 802.11a and HIPERLAN/2. In addition, the rejected frequency band can be varied by adjusting the length and location of the ring-shape parasitic patch. By means of a normalized antenna transfer function, both the frequency-domain and time-domain characteristics of the antenna are carefully investigated. The fabricated antenna can achieve broad bandwidth covering 2.2 to 11.8 GHz with VSWR below 2. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:1310–1313, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21614

35 citations

Proceedings ArticleDOI
04 Dec 2005
TL;DR: In this article, a novel UWB antenna with a band elimination characteristic is presented, which consists of the planar monopole type with a ring-shaped parasitic patch rejecting 5.15/spl sim/5.825GHz band limited by IEEE 802.11a and HIPERLAN/2.
Abstract: A novel UWB antenna with a band elimination characteristic is presented. The proposed antenna is fed by microstrip line, and it consists of the planar monopole type with a ring-shaped parasitic patch rejecting 5.15/spl sim/5.825GHz band limited by IEEE 802.11a and HIPERLAN/2. The fabricated antenna can achieve the broad bandwidth covering from 2.2 to 11.8GHz with VSWR below 2. The proposed antenna performances are very suitable for the UWB applications.

5 citations


Cited by
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Journal ArticleDOI
Yan Zhang1, Wei Hong1, Chen Yu1, Zhenqi Kuai1, Yu-Dan Don1, Jianyi Zhou1 
TL;DR: In this article, three types of ultrawideband (UWB) antennas with triple notched bands are proposed and investigated for UWB communication applications, which consist of a planar circular patch monopole UWB antenna and multiple etched slots on the patch and/or split ring resonators (SRRs) coupled to the feed line.
Abstract: Three types of ultrawideband (UWB) antennas with triple notched bands are proposed and investigated for UWB communication applications. The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the patch and/or split ring resonators (SRRs) coupled to the feed line. Good agreement is achieved between the simulated and measured results. These techniques are significant for designing UWB antennas with multiple narrow frequency notched bands or for designing multiband antennas.

310 citations

Journal ArticleDOI
TL;DR: In this paper, a planar ultrawideband (UWB) antenna with band-notched function is proposed, which consists of a radiation patch that has an arc-shaped edge and a partially modified ground plane.
Abstract: A novel planar ultrawideband (UWB) antenna with band-notched function. The antenna consists of a radiation patch that has an arc-shaped edge and a partially modified ground plane. The antenna that makes it different from the traditional monopole antenna is the modification in the shape of ground plane, including two bevel slots on the upper edge and two semicircle slots on the bottom edge of the ground plane. These slots improve the input impedance bandwidth and the high frequency radiation performance. With this design, the return loss is lower than 10 dB in 3.1-10.6 GHz frequency range and the radiation pattern is highly similar to the monopole antenna. By embedding a pair of T-shaped stubs inside an elliptical slot cut in the radiation patch, a notch around 5.5 GHz WLAN band is obtained. The average gain is lower than -18 dBi in the stopband, while the patterns and the gains at frequencies other than in the stopband are similar to that of the antenna without the band-notched function.

207 citations

Journal ArticleDOI
TL;DR: In this paper, a planar ultrawideband (UWB) antenna with band notched characteristics is presented, which is suitable for UWB applications due to its compact size and high performance.
Abstract: A compact planar ultrawideband (UWB) antenna with band notched characteristics is presented. Modification in the shape of radiation element and ground plane with two symmetrical bevel slots on the lower edge of the radiation element and on the upper edge of the ground plane makes the antenna different from the rectangular printed monopole. These slots improve the input impedance bandwidth and the high frequency radiation characteristics. With this design, the reflection coefficient is lower than 10 dB in the 3.1-10.6 GHz frequency range and radiation pattern is similar to dipole antenna. With the inclusion of an additional small radiation patch, a frequency-notched antenna is also designed and good out of band performance from 5.0-6.0 GHz can be achieved. Measured results confirm that the antenna is suitable for UWB applications due to its compact size and high performance. Also an approximate empirical expression to calculate the lowest resonant frequency is proposed.

206 citations

Journal ArticleDOI
TL;DR: In this paper, two CPW-fed elliptical monopoles were fabricated on liquid crystal polymer (LCP) with reconfigurable rejection band (band-notch) characteristics in the frequency range between 5 and 6 GHz.
Abstract: Two CPW-fed elliptical monopoles were fabricated on liquid crystal polymer (LCP) with reconfigurable rejection band (band-notch) characteristics in the frequency range between 5 and 6 GHz. The first antenna uses a lambda/2 long, U-shaped slot and the second antenna uses two symmetrically placed lambda/4 long, inverted L-shaped stubs as resonating elements. Microelectromechanical system (MEMS) switches are used to activate and deactivate the resonating elements without the need of dc bias lines due to a novel design of the switch geometry. Transmission line models and surface current distributions are used to explain the effect of the added resonating elements. Reflection coefficient radiation pattern and gain measurements are presented to verify the design concepts featuring a very satisfactory performance.

193 citations

Journal ArticleDOI
TL;DR: Fallahi, Kalteh, and Golparvar Roozbahani as discussed by the authors presented a novel band-notched elliptical slot antenna for UWB communication, which is printed on a dielectric substrate of RT/duroid 6006 with relative permittivity (er) of 6.0, thickness of 1.27 mm, and fed by an elliptical open ended microstrip line connected to the 50 Ω main line.
Abstract: This paper presents a novel band-notched elliptical slot antenna for Ultra Wide-Band (UWB) communication, which is printed on a dielectric substrate of RT/duroid 6006 with relative permittivity (er) of 6.0, thickness of 1.27 mm, and fed by an elliptical open ended microstrip line connected to the 50 Ω main line. This antenna is designed to be used in frequency band of 3.1–10.6 GHz. Bandnotched characteristics of antenna to reject the frequency band of 5.15–5.825GHz, which is limited by IEEE 802.11a, is realized by parasitic inverted-U strip attached to the elliptical slot plane. Effects of varying the parameters of parasitic inverted-U strip on performance of proposed antenna have been investigated. The antenna with optimal parameters obtained from parametric study is fabricated and measured. It is observed that the simulation and experimental results have good agreements with each other. 128 Fallahi, Kalteh, and Golparvar Roozbahani

191 citations