• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.1
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• pp.58-65
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• 2013

It's introduced a BLA(Branch Loop Antenna) that is modified from conventional loop, and verified antenna performances for applying to mobile handset. Branch elements are added to a rectangular loop, and low resonance is obtained by the length of the branch line. When resonance frequency of a single loop is 2.5GHz, BLA had near 900 MHz under the same antenna size. Multiple resonances are established by the locations of branch connection and their lengths. By the implementation and measurement for the dual band BLA, it's showed 75MHz -10dB bandwidth and -3.03~-1.46dBi average gains with 49.73~71.39% efficiencies at GSM900 band, and 90MHz -6dB bandwidth and -8.14~-2.17dBi average gains with 15.34~60.62% efficiencies at DCS1900 band. And H-plane radiation patterns were omni-directional. These performances are good for the mobile handset antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.12 s.103
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• pp.1194-1205
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• 2005

This paper proposes a uni-planar elliptical element UWB antenna with band-notched characteristic and modified pound plane fed by CPW. The antenna achieves VSWR below 2 for UWB band(3.1 GHz${\~}$10.6 GHz). In addition, a band-notched characteristic is achieved by inserting a horizontal slot on the radiation element to avoid the interference with 5 GHz(5.15 GHz${\~}$5.825 GHz) band limited by IEEE 802.1la. The antenna has a thin profile, compact size, and ease of manufacture by adopting a CPW feed structure without any additional background plane. Measured data show that the proposed antenna has good return loss below -10 dB, about 2.1 dB${\~}$4.75 dB maximum gain over the bandwidth, omni-directional radiation patterns, linear phase response.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.10-14
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• 2017

A reverberation chamber is widely used in mobile handset measurements due to its faster and simpler measurement process compared to traditional anechoic chambers. We propose an ultra-wideband inverse conical antenna design suitable as a reference antenna in a reverberation chamber. Traditionally, multiple discone antennas are needed to cover more than 10:1 operation bandwidth of a reverberation chamber. The proposed inverse conical antenna offers wideband impedance matching bandwidth by virtue of the linear impedance transition along its oblique side. The antenna is feasible to mount on the conductive walls which can be utilized as a ground to improve the matching bandwidth, antenna gain and radiation patterns. The antenna geometry is optimized using a 3D electromagnetic simulation tool and fabricated using a 3D printer. The measured results show that the antenna reflection coefficient lower than -10dB and radiation efficiency more than 70% at the frequency range of 0.65~7 GHz.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.161-167
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• 2012

Portable devices such as smartphones with built-in wireless LAN to the prevalence of anyone using. But the wireless Internet connection and positioning services are limited to high-quality wireless service, they may not be available. Thus, wireless LAN infrared sensor in the same way as with angry alternative way wireless capabilities of the application automatically identify the location of the Sensor application as an alternative method is proposed. Thus, wireless LAN, such as infrared sensors and other alternzative methods of wireless features in a way where the application can recognize and automatically recognize the sensor application as an alternative method is proposed. Sensor is signals between wireless LAN and access points using the sensitivity, WLAN antenna with omni-directional signal output operation of the sensor is assumed to be recognize this by putting a direction to obtain through the proposed algorithm, Sensors such as photo-coupler without direct recognition sensor, wireless LAN and access points, the same function as the connection between the sensitivity to perform its function was to utilizing.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.52-58
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• 2009

We propose a folded monopole antenna with loads, and analyze the roles of design parameters which affect the return loss of the proposed antenna. VSWR < 3 bandwidth of the antenna is 30 ~ 2000 MHz, ranging from the HF/VHF/UHF bands. For operating travelling antenna, we connect six loads at the end of the antenna. The reflected wave is drastically reduced due to the six loads. For improved return loss properties, we use Klopfenstein tape that determine positions and values of six loads. The propose antenna has omni-directional radiational patterns like that of conventional monopole antennas. For wideband impedance transformation, we use the balun which operating frequency region is 10 ~ 1900 MHz. We expect the proposed antenna has important role for the wideband and multi-rold multi-functional communication systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.5
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• pp.665-675
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• 2001

In this paper, the reverse link performance of a imperfect power controlled DS/CDMA cellular system that uses a base station array antenna which can effectively remove the multiple access interference is analyzed considering both beam forming algorithm and power control error in shadowing. The blocking probability of the DS/CDMA cellular system based on array parameters, $E_b/N_o$ and statistics of interference is derived, and then the system capacity corresponding to a certain blocking probability is calculated. On the assumption that the blocking probability is set 1%, the system capacity using MCGM algorithm with 12 antenna arrays is more increased maximum 32 times than that using a omni-directional antenna and about 2 times than that using MMSE algorithm, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.493-500
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• 2008

This paper describes a design of internal frequency modulation(FM) radio antenna fur mobile terminal. In order to control of impedance at an operating frequency of the designed antenna, the lumped constant elements of R and L chip components are used. Patch and stubs located at antenna backside are added to control an exact resonance frequency and miniaturization. A fabricated antenna sire, the measured return loss, impedance, bandwidth, and gain are $40{\times}70{\times}1$ mm, -23 dB at 99 MHz, $55-j7{\Omega}$, 22 MHz($88{\sim}110$ MHz) below -10 dB, and -15 dBi, respectively. These measured results show a good agreement with simulated results. Especially, the measured gain of fabricated antenna is similar with value of a conventional ear-phone antenna in the designed frequency band. The measured radiation pattern agrees well with the calculated omni-directional pattern.

• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.515-522
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• 2008

In this paper, a slot antenna with built-in Bazooka balun aimed for a WiBro repeater was designed and fabricated. The return loss and radiation pattern of the slot antenna were improved due to the introduced Bazooka balun. This balun brings about even radiation pattern and keeps the stabilized coverage of repeater And it is easy to unite this balun with the antenna body by providing the terminal of Bazooka balun with screw shape. H-type slot was used to reduce the size of the antenna, and the slot antenna was fabricated in the structural symmetry with respect to a feeding point to afford the omni-directional radiation pattern. The simulated results were obtained by MWS(Microwave Studio Simulator) of CST company, and the measurement on the proposed antenna was conducted in an anechoic chamber equipped with a network analyzer and a far field measurement system. The measured peak gain shows 5.75 dBi and the average gain is above -0.8 dBi. The return loss remains below -12.35 dB for all frequency bands in WiBro regarded as a good performance.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.549-555
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• 2011

In this paper, inverted triangle structural planar monopole antenna with Edge for UWB Communication (3.1 ~ 10.6 GHz) is presented. The antenna have broadband property structurally through inverted triangle structural planar monopole which have edge. Monopole and ground of proposed antenna exist on coplanar plane, and excite as CPW. It used FR4 dielectric substrate of ${\epsilon}_r=4.4$, and the size is $20{\times}20{\times}1.6mm$. Return loss is more than - 10dB in 3.1 ~ 10.1 GHz (7.0 GHz). Radiation pattern is about the same that of dipole antenna at all frequency. At measured result, max gain is 8.44 dBi at E - plane.