• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7309-7316
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• 2014

In this paper, a triple-band multiplexer using a microstrip transmission line was designed and fabricated to make use of a low power portable base station. This multiplexer was used in the triple-band including the cellular, WCDMA and LTE mobile frequency band, and designed to have an insertion loss of 0.8 dB, low SWR of 1.5 in the passband and a band rejection of 15 dB in the stopband. From the measured results obtained by a confidence test for the fabricated multiplexer samples, the maximum insertion loss and SWR of the fabricated multiplexer samples in all passbands of 824-894MHz, 1920-2170 MHz and 2500-2600 MHz were below 0.71 dB and 1.38, and the attenuations in the stopbands were better than 15 dB. Therefore, the triple-band multiplexer has good performance and satisfies the design specifications.

• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.4
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• pp.295-301
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• 2011

A triple-band transceiver module for 2.3/2.5/3.5 GHz mobile WiMAX, IEEE 802.16e, applications is introduced. The suggested transceiver module consists of RFIC, reconfigurable/multi-resonance MIMO antenna, embedded PCB, mobile WiMAX base band, memory and channel selection front-end module. The RFIC is fabricated in $0.13{\mu}m$ RF CMOS process and has 3.5 dB noise figure(NF) of receiver and 1 dBm maximum power of transmitter with 68-pin QFN package, $8{\times}8\;mm^2$ area. The area reduction of transceiver module is achieved by using embedded PCB which decreases area by 9% of the area of transceiver module with normal PCB. The developed triple-band mobile WiMAX transceiver module is tested by performing radio conformance test(RCT) and measuring carrier to interference plus noise ratio (CINR) and received signal strength indication (RSSI) in each 2.3/2.5/3.5 GHz frequency.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.67.1-67.1
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• 2010

Triple junction solar cell을 위한 a-SiGe middle cell의 조건별 광학적 특성에 관한 연구를 실시하였다. a-SiGe I층은 GeH4 유량, 압력, H2 dilution ratio를 변화시켜 제조하였으며 전기적, 광학적 특성을 비교하여 최종적으로 선택된 조건을 triple junction solar cell에 적용하였다. a-SiGe I층은 Ge contents가 증가함에 따라 band gap은 감소하고 45% 이상의 조건에서는 700nm 전후 파장의 투과율이 감소하며, 압력이 감소함에 따라 band gap은 소폭 감소하나 700nm 전후 파장의 투과율은 증가하였다. 그리고 H2 ratio가 증가함에 따라 band gap은 소폭 감소하나 투과율에는 큰 변화가 없었다. 상기 결과를 바탕으로 최종적으로 선택된 조건에서 triple-junction solar cell을 제작하여 평가한 결과 초기 변환효율 9%의 결과를 얻었다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.2
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• pp.271-276
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• 2017

The triple-gate tunnel FETs encapsulated with an epitaxial layer (EL TFETs) is proposed to lower the subthreshold swing of the TFETs. Furthermore, the band-to-band tunneling based on the maximum electric-field can occur thanks to the epitaxial layer wrapping the Si fin. The performance and mechanism of the EL TFETs are compared with the previously proposed TFET based on simulation.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.33-40
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• 2019

In this paper, a microstrip-fed triple-band antenna for WLAN system with microstrip lines was designed, fabricated and measured. The proposed antenna is composed of two strip lines and slit in the ground plane and then designed in order to get triple band characteristics. We carried out simulation on $L_3$, $L_{10}$, and slit parameters, and adjusted the parameters of the proposed antenna to satisfy the required frequency band and bandwidth. The proposed antenna is made of $32.0{\times}44.0{\times}1.0mm$ and is fabricated on the permittivity 4.4 FR-4 substrate. The experiment results shows that the proposed antenna obtained the -10 dB impedance bandwidth 120 MHz (890 MHz~1.01 MHz), 440 MHz (2.35~2.79 GHz), and 1,280 MHz (5.07~6.35 GHz) covering the triple WLAN bands. Also, the measured gain and radiation patterns characteristics of the proposed antenna are presented at required frequency band, respectively.

• ETRI Journal
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• v.37 no.1
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• pp.21-25
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• 2015

A miniaturized triple-band antenna suitable for wireless USB dongle applications is proposed and investigated in this paper. The presented antenna, simply consisting of a circular-arc-shaped stub, an L-shaped stub, a microstrip feed line, and a rectangular ground plane has a compact size of $16mm{\times}38.5mm$ and is capable of generating three separate resonant modes with very good impedance matching. The measurement results show that the antenna has several impedance bandwidths for S11 ${\leq}$ -10 dB of 260 MHz (2.24 GHz to 2.5 GHz), 320 MHz (3.4 GHz to 3.72 GHz), and 990 MHz (5.1 GHz to 6.09 GHz), which can be applied to both 2.4/5.2/5.8 GHz WLAN bands and 3.5/5.5 GHz WiMAX bands. Moreover, nearly-omni-directional radiation patterns and stable gain across the operating bands can be obtained.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.768-773
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• 2010

In this paper, we study on an optimal design of a triple-band PIFA (Planar Inverted-F Antenna) of 433 MHz, 912 MHz and 2.45 GHz by using evolution strategy. Generally, the resonant frequency of the PIFA is determined by the width and length of a U-type slot used. However the resonant frequencies of the multiple U slots are varied by the mutual effect of the slots. Thus the optimal width and length of U-type slots are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The resonant frequencies of initial model are 439.5 MHz, 981.5 MHz and 2.563 GHz. However, the resonant frequencies of the triple-band PIFA yielded by the optimal design program are 430.5 MHz, 907 MHz and 2.4515 GHz. Measured resonant frequencies are 433.5 MHz, 905.5 MHz and 2.454GHz, which show a good agreement with the simulation results.

• Journal of electromagnetic engineering and science
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• v.3 no.1
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• pp.23-28
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• 2003

In this paper, a triple-band planar antenna is proposed for the application to miniaturized automobile safety devices operating at X band(10.5 ㎓), K band(24.15 ㎓), and Ka band(34.3 ㎓). The frequency ratio between the resonant frequencies of this antenna can be adjusted from 1.99 to 2.23 for both X band and K band by varying its slit length. Parasitic elements are added on the modified slot loaded antenna to obtain the third resonance. From numerical as well as experimental results, it has been confirmed that this type of antenna is appropriate for planar multi-band antenna systems.

• Journal of electromagnetic engineering and science
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• v.15 no.1
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• pp.6-13
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• 2015

In this paper, a novel monopole antenna for WLAN/WiMAX application is presented. The proposed antenna consists of two arc-shaped strips, a vertical strip, and a slot in the ground plane. In this study, a prototype of the proposed triple-band antenna was designed, fabricated, and tested. The quantitative and experimental results demonstrate that the proposed antenna satisfy the -10 dB impedance bandwidth requirement of 440 MHz for 2.4/2.5 GHz bands (from 2.26 to 2.70 GHz), 970 MHz for 3.5 GHz bands (from 3.27 to 4.24 GHz), and 870 MHz for the GHz bands (from 5.08 to 5.95 GHz), while simultaneously covering the WLAN and WiMAX bands. In addition, the presented triple-band antenna has an omnidirectional radiation pattern at all three frequency bands with an antenna gain of 4.45 dBi for the lowest band, 2.04 dBi for the middle band, and 3.98 dBi for the highest band.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.119-126
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• 2019

In this paper, a monopole antenna applicable to WLAN standardization is designed, fabricated, and tested. The proposed antenna is designed to have three microstrip lines based on microstrip feeding method and inserted one stub to enhance impedance characteristics. Then, it obtained triple band characteristics of the proposed antenna. We adjusted and optimized the lengths and width of the three microstrip lines and one inserted stub to obtain the required impedance bandwidth for this paper. The proposed antenna has $23.0mm(W){\times}53.1mm(L1)$ on a dielectric substrate of $24.0mm(W1){\times}60.0mm(L){\times}1.0mm$ size. From the fabrication and measurement results, bandwidths of 158 MHz (841 to 1000 MHz) for 900 MHz band, 630 MHz (2.32 to 2.95 GHz) for 2400 MHz band, and 1,040 MHz (4.95 to 5.99 GHz) for 5000 MHz band were obtained based on the impedance bandwidth. The fabricated antenna also obtained the measured gain and radiation pattern characteristics in the required triple band of the proposed antenna.