• Journal of electromagnetic engineering and science
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• 제13권1호
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• pp.51-53
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• 2013

A MIMO antenna using the resonance of ground planes is proposed for 4G mobile application. A resonant mode is generated when the double ground planes (upper and lower) in the mobile terminal are excited as the radiator. By combining the resonant modes contributed from both the antenna element and the ground planes, the proposed MIMO antenna realizes a wideband property over LTE band 13. In addition, an inductive coil is employed to reduce the antenna volume. These approaches not only simplify antenna design but also effectively improve bandwidth and efficiency. The proposed MIMO antenna has an excellent ECC value of below 0.1 because of the nearly orthogonal radiation patterns of the two radiators. Moreover, an additional antenna is adopted to cover WiMAX, WLAN, and Bluetooth services simultaneously in frequency range from 2 GHz to 2.7 GHz.

• Journal of electromagnetic engineering and science
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• 제2권1호
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• pp.45-49
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• 2002

This paper presents the basic characteristics of a forced resonant type EMI dipole antennas for frequencies below 80 MHz in which two reactance elements are used for the impedance matching at the fined point. The input impedance of the short dipole less than half-wavelength is controlled by the properly determined loading position and the value of loading reactance. The numerical results show that the small-sized EMI dipole antenna with loller antenna factors for frequencies below 80 MHz can be realized by the reactance loading. In case tole proposed center driven forced resonant type EMI dipole antenna with 0.3 λ length is loaded from the center, the input impedance is matched at feed line with 50 $\Omega$, and hence the antenna has lower factors in the frequency range of 30 to 80 MHz.

• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.152-156
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• 1989

Parameters of a microstrip patch antenna such as the resonant frequency, radiation conductance, and the bandwidth are calculated. The rectangular microstrip patch antenna fed by a microstrip transmission line is fabricated and its resonant frequency, radiation pattern, and input voltage standing wave ratio are measured. The measured resonant frequency for 13.0mm$\times$9.7mm copper clad woven PTFE/glass laminate plate is 9.06Ghz, where the calculative is 9.00Ghz. And the measured vswr shows that the bandwidth of the antenna is 225MHz for vswr less then 2.0 which the calculated quality factor of the patch gives the bandwidth OF 280ghZ. The measured radiation pattern for 5 element as well as 4 element patch array shows less then 4dB deviation in the first side lobes from the designed values for both E and H plane pattern. This diviation is believed to be the power division errors of the power divider.

• 한국컴퓨터정보학회논문지
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• 제15권8호
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• pp.59-66
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• 2010

본 논문은 안테나 구조체의 물리적 변화없이 안테나의 단락점에 연결되어있는 인덕터 값에 따라 급전점과 단락점 사이의 결합계수 뿐 아니라 안테나의 공진 주파수를 조절할 수 있는 이동통신용 안테나를 구현하였다. 설계된 안테나는 3중 대역 이상의 주파수 조절이 가능하고 동작 주파수 대역은 GSM(880~960MHz), GPS(1575MHz), DCS(1710~1800MHz), US-PCS(1850~1990MHz), WCDMA(1920~2170MHz) 대역을 포함한다. 제작된 안테나는 반파장 로디드 라인 안테나와 PIFA 구조를 결합한 형태이고 두 개의 단란점과 하나의 급전점을 공유한다. 두 개의 단락점 각각에 인덕터를 추가하여 하나의 인덕터는 급전점과 단락점 사이의 결합계수를 조절하고 다른 하나의 인덕터는 높은 주파수 대역의 공진 주파수를 조절한다. 안테나의 입력 임피던스 조절을 위한 인덕턴스의 범위는 0nH ~ 6.8nH 이고 이득의 변화는 GSM 대역에서는 0.15dBi, GPS 대역에서는 0.73dBi, WCDMA 대역에서는 0.29dBi 이내이다. 또한 공진 주파수 조절을 위한 인덕턴스의 범위는 0nH ~ 4.7nH의 범위에서 1640~2500 MHz (VSWR 3:1 기준)이고 이득의 변화는 GSM 대역에서는 0.46dBi, GPS 대역에서는 0.53dBi, DCS/US-PCS/WCDMA 대역에서는 0.59dBi 이내이다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.217-220
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• 2004

This paper presents design simulation, implementation, and measurement of a miniaturized GPS/K-PCS dual-band LTCC chip antenna for mobile communication handsets. The dimension of LTCC chip antenna is $9mm{\times}15mm{\times}1.2mm$. The lower meander type antenna is to be tuned to the lower frequency (GPS) band and the upper meander antenna with via hole connection is to contribute the higher frequency (K-PCS) band. In order to lowering the resonant frequency for GPS band, two printed modified meander antenna with gap stub is used to integrate with PCS band operation. The measured resonant frequency at GPS band shifts to lower frequency about 100MHz. The measured impedance bandwidth(VSWR $\leq$ 2) are 55MHz and 120MHz at the resonant frequency. respectively.

• 한국전자파학회논문지
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• 제22권1호
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• pp.106-113
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• 2011

본 논문에서는 구형 도파관의 협벽에 이중 슬롯을 가진 비공진형 슬롯 도파관 안테나를 설계하였다. 설계된 협벽 슬롯 도파관 안테나는 슬롯의 기울임 각도에 의해 복사되는 에너지가 결정되기 때문에, 요구되는 부엽 크기를 만족시키는 복사에너지의 크기 분포가 나오도록 각 슬롯의 기울임 각도를 조정하였다. 기울임 각도의 조정은 기존의 슬롯 도파관 안테나의 설계에서 주로 사용되는 슬롯 컨덕턴스 추출 방법이 아닌, 개개의 슬롯 개구면 필드를 푸리에 변환하여 원전계 복사 패턴을 계산하고, 원전계 복사 패턴으로부터 최대 크기의 분포를 산출하는 방법을 사용하였다. 제안된 방법으로 비공진형 이중 슬롯 도파관 안테나를 설계하고, 실제 제작하여 안테나 성능을 측정, 비교하였다.

• Journal of electromagnetic engineering and science
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• 제11권3호
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• pp.220-226
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• 2011

We have proposed a new method to accurately predict the resonance of Fabry-Perot Cavity (FPC) antennas enclosed with conducting side walls. When lateral directions of an FPC antenna are not blocked with metallic walls, the conventional technique is accurate enough to predict the resonance of the FPC antenna. However, when the FPC antenna has side walls, especially for case with only a short distance between the walls, the conventional prediction method yields an inaccurate result, inevitably requiring a tedious, time-consuming tuning process to determine the correct resonant height to provide the maximum antenna gain in a target frequency band using three-dimensional full-wave computer simulations. To solve that problem, we have proposed a new resonance prediction method to provide a more accurate resonant height calculation of FPC antennas by using the well-known resonance behavior of a rectangular resonant cavity. For a more physically insightful explanation of the new prediction formula, we have reinvestigated our proposal using a wave propagation characteristic in a hollow rectangular waveguide, which clearly confirms our approach. By applying the proposed technique to an FPC antenna covered with a partially reflecting superstrate consisting of continuously tapered meander loops, we have proved that our method is very accurate and readily applicable to various types of FPC antennas with lateral walls. Experimental result confirms the validness of our approach.

• ETRI Journal
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• 제30권4호
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• pp.603-605
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• 2008

A novel design for equilateral-triangular microstrip antennas with switchable resonant frequency is proposed. For dual-frequency operation, the proposed design is achieved by loading a pair of slits in the triangular patch, and two PIN diodes are utilized to switch the slits on or off. By increasing the length of the slits, the lower resonant frequency can be varied in the range from 1.22 GHz to 1.72 GHz whereas the upper resonant frequency remains unchanged.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1134-1136
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• 2002

This paper proposes a FSK(Frequency Shift Keying) transmitter which has a inverter for power amplification instead of linear amplifier. As it can generate large signal using resonant circuit under the low voltage source even if the impedance of antenna is large as like a loop antenna of TWC(Train to Way-side Communication) system. In this paper, the proposed fully digital controlled transmitter including FSK modulation is presented and its control schemes are discussed.

• ETRI Journal
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• 제37권2호
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• pp.204-211
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• 2015

For this study, we designed an implantable rectangular spiral antenna for medical biotelemetry in the Medical Implant Communications Service band (402 MHz to 405 MHz). The designed antenna has a U-shaped loop for impedance matching. The antenna impedance is easily adjusted by controlling the shape and length of the U-shaped loop. Significant design parameters were studied to understand their effects on the antenna performance. To verify the potential of the antenna for the desired applications, we fabricated a prototype and measured its performance in terms of the resonant characteristics and gain radiation patterns of the antenna. In the testing phase, the prototype antenna was embedded in human skin tissue-emulating gel, which was developed to simulate a real operation environment. The measured resonant characteristics show good agreement with the simulations, and the -10 dB frequency band is within the range of 398 MHz to 420 MHz. The antenna exhibits a maximum gain of -22.26 dBi and an antenna efficiency of 0.215%.