• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.20-26
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• 2013

In this paper, we propose a multi-band monopole antenna with a band-notching U-slot, which is fabricated inside the flexible polymide film substrate. The U-shaped slot located on the patch-shaped monopole antenna provides band-notch at 2.7 GHz, but also helps to improve return loss at adjacent frequency bands. The performance of the antenna attached on an automobile-glass has been simulated and measured. The fabricated antenna provides more than 10 dB return loss for ISM band(2.4~2.483 GHz) and WAVE band(5.85~5.925 GHz), 2.8~5.7 dBi maximum gain, and good radiation patterns.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.5
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• pp.435-443
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• 2009

In this paper, we propose a microstrip slot antenna that works in Bluetooth, Zigbee, WiMAX and WLAN frequency bands($2.4{\sim}5.825\;GHz$). To get the wide bandwidth from the microstrip antenna proposed, we insert a pair of parastic strips along the feed line on the FR-4 dielectric substance(${\varepsilon}_r=4.8$). Furthermore, a simple geometrical rotation with quadrilateral slot is designed to maximize the bandwidth and to gain a wider frequency band than the conventional rectangular slot antenna. A additional design of the loop type is added to a cactus-shaped patched for 2.4 GHz ISM frequency band. The total measured bandwidth of the antenna is from 2.4 GHz to 6 GHz and the maximum gains of the antenna are 3.82 dBi, 4.48 dBi, 6.41 dBi and 6.65 dBi at the frequencies of 2.4 GHz, 3.5 GHz, 5.25 GHz and 5.77 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.167-173
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• 2009

This paper proposes an electronically beam steering array antenna, consisting of single fed active element and 4 parasitic elements, operating in 5.8 GHz ISM band. Beam steering can be achieved by controlling the reactance of the variable reactance control circuit connected to the load of the parasitic elements without using the high cost phase shifters. The proposed antenna realizes ${\pm}30^{\circ}$ beam scanning of E-plane and H-plane with the below -10 dB return loss in ISM band. The gain of the $6.18{\sim}7.53\;dBi$ in E-plane and $7.022{\sim}7.779\;dBi$ in H-plane is shown in the scanning range.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.187-192
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• 2017

We investigated the effects of the CSRR-metamaterial on microstrip comb-line array antennas. Microstrip comb-line array antennas was designed with 12 radiators, gain of 16.09dBi and bandwidth of 0.24GHz in the 24GHz ISM band. The designed antenna had radiation beam perpendicular to the antenna plane, co-polarization gain of 16.09dBi and cross-polarization gain of -10.86dBi. the CSRR-metamaterial increased largely the impedance bandwidth of the antenna from 0.24GHz to 3.6GHz. however as co-polarization gain became 10.08dBi and cross-polarization gain became 14.1dBi, co-polarization was mixed with cross-polarization. And the antenna gain lowered by 1.99dB. On the investigation of the dependence on the split-direction of the CSRR rings, it showed nearly the same characteristics for up-splitted ring used case and down-splitted ring used case. However in the case of arranging up-splitted ring and down-splitted ring in alternation, co-polarization gain decreased to -1.29dBi and cross-polarization gain increased to 13.9dBi, which meant the wave was transited to cross-polarization majority wave.

• Journal of IKEEE
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• v.8 no.1 s.14
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• pp.86-95
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• 2004

In this paper, we designed, fabricated, and measured antenna results consisting of previous research, that can handle from wireless using-LAN U-shaped slot antenna of HiperLAN bandwidth to ISM band of HiperLAN 1/2 & 5 GHz bandwidth. We presented a new model that structuresof basic U-shaped slot added the same thing twice.After the foam layer is inserted between ground plane and substrate, we got enough bandwidth for VSWR<1.5. The antenna gain was $6.27{\sim}9.82dBi$. The radiation pattern got a stable pattern in frequency bandwidth.

• Journal of Sensor Science and Technology
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• v.20 no.3
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• pp.145-150
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• 2011

In this paper, we designed a tunable microstrip patch antenna using RF MEMS switches. The design and simulation of the antenna were performed using a high frequency structure simulator(HFSS). The antenna was designed for use in the ISM band and either operates at 2.4 GHz or 5.7 GHz achieving -10 dB return-loss bandwidths of 20 MHz and 180 MHz, respectively. In order to obtain high efficiency and improve the ease of integration, a high resistivity silicon(HRS) wafer on a glass substrate was used for the antenna. The antenna achieved high gains: 8 dB at 5.7 GHz and 1 dB at 2.4 GHz. The RF MEMS DC contact switches were simulated and analyzed using ANSYS software.

• Journal of Digital Convergence
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• v.10 no.3
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• pp.265-271
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• 2012

This paper proposes a communication distance performance evaluation method for mobility of service robots equipped with a Wi-Fi module. Service robots have function of mobile communication system according to classified services and utilize a (preferred) communication method, wireless lan(IEEE802.11 a/b/gin) communication method of ISM band(2.4GHz and 5.8GHz). For evaluating degradation performance of wireless data for the service robot's mobility. We measured and presented reference vectors obtained by utilizing a distance attenuation correlation method in the real world environment. To evaluate performance of the proposed method, path loss of reference vectors was assigned to the Azimuth 301W and then transmission rate and the transmit throughput of the test sample were measured by the Chariot. The proposed measurement method is necessary for securing wireless LAN communication distance for mobility of mobile smart device and service robots. In addition, if the proposed measurement method os adopted, It would be expected that mobile smart device vendors would utilize the method as an effective wireless LAN mobility communication distance performance evaluation method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.129-129
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• 2009

In this paper, a tunable microstrip patch antenna designed using RF MEMS switches is reported. The design and simulation antenna were performed using high frequency structure simulator (HFSS). The antenna was designed in ISM Band and operates simultaneously at 2.4 GHz and 5.7 GHz with a -10 dB return-loss bandwidth of 20 MHz and 180 MHz, respect-tively. To obtain high efficiency and improve integrated ability, the High Resistivity Silicon (HRS) wafer was used for the antenna. The antenna achieved high gain with 8 dB at 5.7 GHzand 1.5 dB at 2.4 GHz. The RF MEMS DC contact switches was simulated and analysis by ANSYS software.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.239-242
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• 2001

본 논문에서는 self-bias 구조를 갖는 소 신호 증폭기에 대해 논의된다 주파수 영역은 ISM band (Industria1/Scientific/Medical band) 인 무선 랜 (WLL : Wireless Local Loop) 대역 5.8GHz 에서 설계하였다. 제시된 self-bias 구조는 단일 전원만을 사용한다는 장점을 가지고 있으며 입력 단에서 RFC (λ/4 전송선로)를 제거하고 매칭 회로에서 단락 스터브를 사용함으로 구조를 간단히 하였다. 이러한 bias조건에서 FET의 이득은 11dB이고 회로 설계 후 측정 결과는 입력 반사 손실 -16.455dB, 이득은 8.095dB이다. 이 소 신호 증폭기는 간단한 구조로 구현된 장점 뿐 만 아니라 무선 랜 분야에서도 충분히 응용 될 수 있으리라 기대된다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.114-121
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• 2003

In this paper, low voltage and two stage CMOS Class E RF power amplifier for ISM(Industrial/Scientific/Medical) Open Band is presented. The power amplifier operates at 2.4GHz frequency, and is designed and simulated with a 0.35um CMOS technology and HSPICE simulator. The power amplifier is simple structure of two stage Class E power amplifier. The design procedure determing matching network was presented. The power amplifier is composed of input stage matching network, preamplifier, interstage matching network, power amplifier, and output stage matching network. The matching networks of input stage and interstage were constituted by pi($\pi$) type and L type respectively. At 2.4GHz operating frequency, and with a 2.5V supply voltage, the power amplifier delivers 23dBm output power to a 50${\Omega}$ load with 39% power added efficiency(PAE).