• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.965-971
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• 2001

In this paper, the triangular u-slot patch antenna for the PCS & IMT-2000 dual band are studied. The frequency bandwidth of a triangular u-slot patch antenna can be increased by L-strip fed structure. The impedance bandwidth(VSWR$\leq$2) of the fabricated single element is 590 MHz(30.18 %). Using the frequency bandwidth of PCS & IMT-2000, we confirm VSWR below 1.65, which is a good characteristic. Thus the wideband characteristic of the L-strip fed structure is confirmed experimentally.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.197-200
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• 2004

In this paper, a novel triple-band planar inverted F antenna(PIFA) is proposed. The goal of this paper is to design a small antenna which is operated in triple band. Using T-shape slit and stacked U-shape parasitic patch, good impedance matching is achieved in three band. T-shape slit is inserted on the main patch in order to effectively control the excited patch surface current distributions. The proposed antenna occupies a small volume of $26{\times}9.5{\times}6mm^3$, and the obtained impedance bandwidths cover the required operating bandwidths of the GPS(1565-1585MHz), IMT-2000(1885-2200MHz) and Bluetooth (2400-2484MHz) bands.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.4
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• pp.437-444
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• 2015

A high output power voltage controlled oscillator (VCO) in the U-band was implemented using a 65 nm CMOS process. The proposed VCO used a transmission line to increase output voltage swing and overcome the limitations of CMOS technologies. Two varactor banks were used for fine tuning with a 5% frequency tuning range. The proposed VCO showed small variation in output voltage and operated at 51.55-54.18 GHz. The measured phase noises were -51.53 dBc/Hz, -91.84 dBc/Hz, and -101.07 dBc/Hz at offset frequencies of 10 kHz, 1 MHz, and 10 MHz, respectively, with stable output power. The chip area, including the output buffer, is $0.16{\times}0.16mm^2$ and the maximum output power was -0.11 dBm. The power consumption was 33.4 mW with a supply voltage of 1.2-V. The measured $FOM_P$ was -190.8 dBc/Hz.

• Journal of the Korean Chemical Society
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• v.7 no.3
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• pp.197-202
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• 1963

The ${\alpha}-and\;{\beta}$-isomer of 4-nitroazoxybenzenes have been separated by liquid chromatography and their U.V. spectra were examined. The n${\to}{\pi}^{\ast}$ transition band of the compounds did not appear, likewise the cases of other compounds of the series. Transition band of the new isomer were as usual as those of other azoxy-compounds, whereas the ${\pi}{\to}{\pi}^{\ast}$ transition band of the other isomer which is reported in the literature shown peculier hypochromic shift and hypochromic effect. From the spectroscopic point of view it is very likely that the new isomer (m.p. $184-5^{\circ}C$) is ${\alpha}$-isomer and the other one (m.p. $152^{circ}C$) is ${\beta}$-isomer contrary to the literature.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.6 s.324
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• pp.93-99
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• 2004

According to rapid increment of demand for wireless Local Area Network (LAN), the HyperLAN of 5.1-533GHz and 5.725-5.825GHz is newly allocated for wireless LAM in many regions over the world. Also, because most of mobile communication equipments are small, the size of antenna is important factor of effective design. In this paper, the compacted and wide bandwidth antenna is designed for wireless LAN at 5GHz band. Although the structure of U-shaped slot antenna is simple, It has large bandwidth of $10-40\%$. Also, the U-slot antenna has good radiation pattern. However, in general, the size of U-slot antenna is large. Therefore, it is difficult to apply to wireless equipment such as PDA and Notebook. This proposed antenna has a wide bandwidth by U-shaped slot in rectangular patch and is compacted by using two layered dielectric substrates and foam. For the design of U-slot antenna, the Finite Difference Time Domain method is applied. Also, the method of MPI parallel program is used for the enhancement of the analyzing speed of the FDTD method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.219-222
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• 2006

In this paper, we have designed 800MHz band broadband antenna which is improves of microstrip antenna narrow bandwidth problem including the CDMA band and be able to integrated the GSM and TRS band will design. It used the duplex resonance effect it had the L-Shaped feeding structure which adds the u-slot. It was measured that the frequency bandwidth of the designed antenna which is planed $897MHz\sim1013MHz$ with 215MHz(23.8%). And the antenna gain is 9.3dBi, 3dB beam width $60^{\circ}$ in both the E-plane and H-plane.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.998-1002
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• 2006

In this paper, we have designed 800MHz band broadband antenna which is improves of microstrip antenna narrow bandwidth problem including the CDMA band and be able to integrated the GSM and TRS band will design. It used the duplex resonance effect it had the L-Shaped feeding structure which adds the u-slot. It was measured that the frequency bandwidth of the designed antenna which is planed $897MHz\sim1013MHz$ with 215MHz(23.8%). And the antenna gain is 9.3dBi, 3dB beam width $60^{\circ}$ in both the E-plane and H-plane.

• Journal of information and communication convergence engineering
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• v.6 no.2
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• pp.172-176
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• 2008

This paper presents a novel feeding structure of the triple-band internal antenna which covers CELLVLAR/DCS/US-PCS bands. The proposed antenna consists of a U-slot patch radiator with a shorting post connected with ground plane and symmetric feeding lines with respective a feeding and shorting posts on both faces of the fixed FR-4 substrate. Through the simulation and experimental results, the proposed antenna is confirmed to have the features of less interference with a human head/body, broad bandwidth, desirable radiation patterns and efficiency for triple-band applications.

• Publications of The Korean Astronomical Society
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• v.5 no.1
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• pp.65-84
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• 1990

The temperature effects of the KNU UBV photometric system are investigated, using the HAMAMATSU 1P21 data. The variation of the passband width of V-band with temperature is about $5{\AA}/^{\circ}C$ while those of B-band and U-band are negligible. This large effect of V-band causes a significant variation of V-mag. and (B-V)-color with temperature such as ${\sim}0.02mag/^{\circ}C$ in both cases. This result strongly suggests that in the photometric observations of binary stars, the temperature effects of the response of photomultiplier and the passband of filters must be considered to avoid the systematic variation in magnitude and color particularly at the minimum of light curve.

• 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.