• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.5
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• pp.426-429
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• 2017

For the W-band remote sensing radiometer, direct detection type radiometer receiver is designed. The receiver should be low noise and high gain of 60 dB unlike communication and radar receiver. The W-band radiometer consist of 4-stage low noise, high gain amplifier, band pass filter and square law detector. The developed direct detection receiver show 4 GHz bandwidth, 56 dB gain, and 4,500 mV/mW voltage sensitivity at integrator output port for -20 dBm input power at 94 GHz.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.11
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• pp.89-94
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• 2011

In this paper, we developed the W-band MMIC low noise amplifier for the millimeter-wave seeker using the tuner system. The MHEMT devices for MMIC LNA exhibited DC characteristics with a drain current density of 692mA/mm, an extrinsic transconductance of 726mS/mm. The current gain cutoff frequency(fT) and maximum oscillation frequency($f_{max}$) were 195GHz and 305GHz, respectively. The fabricated W-band low noise amplifier represented S21 gain of 7.42dB at 94 GHz and noise figure of 2.8dB at 94.2 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.227-232
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• 2007

In this paper, we propose Triple-band antenna, which is practicable for the transmission and the reception of the frequency band used in mobile broadcast and mobile internet. We choose T-DMB(Band-III), DAB(L-Band) for a mobile broadcast and Wibro for a mobile internet. The size of proposal antenna measures $10{\times}74{\times}0.6[mm^3]$. Although being defective in that T-DMB bandwidth is rather narrow, the antenna, considering the reception environment, has an advantage of a realistic possibility of reception in 8 channel($180{\sim}186$ MHz)and 12 channel($206{\sim}210$ MHz) of T-DMB band, being given broadcast services. Also It has gains similar characteristics of ideal dipole antenna in DAB and Wibro band.

• Journal of electromagnetic engineering and science
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• v.15 no.4
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• pp.232-238
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• 2015

This work describes the development of a D-band (110-170 GHz) signal source based on a SiGe BiCMOS technology. This D-band signal source consists of a V-band (50-75 GHz) oscillator, a V-band amplifier, and a D-band frequency doubler. The V-band signal from the oscillator is amplified for power boost, and then the frequency is doubled for D-band signal generation. The V-band oscillator showed an output power of 2.7 dBm at 67.3 GHz. Including a buffer stage, it had a DC power consumption of 145 mW. The peak gain of the V-band amplifier was 10.9 dB, which was achieved at 64.0 GHz and consumed 110 mW of DC power. The active frequency doubler consumed 60 mW for D-band signal generation. The integrated D-band source exhibited a measured output oscillation frequency of 133.2 GHz with an output power of 3.1 dBm and a phase noise of -107.2 dBc/Hz at 10 MHz offset. The chip size is $900{\times}1,890{\mu}m^2$, including RF and DC pads.

• YAKHAK HOEJI
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• v.30 no.6
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• pp.343-347
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• 1986

Korean ginseng was purified to obtain radioprotective protein fractions by buffer extraction, ammonium sulfate fractionation, CM-cellulose column chromatography, heat inactivation and Sephadex G-75 column chromatography. The final three fractions, GI, GII and GIII were subjected to Disc-polyacrylamide gel electrophoresis (PAGE) and SDS-PAGE. The molecular weights(M.W.) of native and denatured proteins were estimated by using regression line equations obtained from the mobilities of standard proteins. As the results, in Disc-PAGE, the GI fraction showed two protein bands with M.W. of above 213, 000 and 55, 000, GII showed one band with M.W. of 44, 000 and GIII, also one band with M.W. of 19, 000. In SDS-PAGE, GI fraction gave four subunit bands with M.W. of above 114, 000, 27, 000, 24, 000 and 19, 000, GII gave two bands with M.W. of 46, 000 and 22, 000, and GIII, one band of 19, 000.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.4 s.119
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• pp.358-363
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• 2007

The multi-band and wide-band antenna for a portable broadcasting terminal is proposed. The proposed antenna consists of two radiators with a parallel structure. The antenna has an enough wide impedance bandwidth for the DVB-H(Digital Video Broadcasting-Handheld) service band since two radiators have adjacent resonance frequencies and operates in the DAB(Digital Audio Broadcasting) service band using the third harmonic of the radiator 1. The fabricated antenna has VSWR characteristics of less than 2:1 in the frequency band $470{\sim}740\;MHz$ for DVB-H and $1,450{\sim}1,480\;MHz$ for DAB. The measured peak gain of the antenna is $1.97{\sim}4.10\;dBi$ in the DVB-H band and $1.98{\sim}2.04\;dBi$ in the DAB band.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.235-240
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• 2005

This paper presents a dual band circularly polarized microstrip patch antenna. The antenna consists of two corner truncated patches implemented in one plane and single feed point. The input signal is directly excited to the patch 2 and the patch 1 is fed from patch 2 by coupling between two patches. The antenna is operated at 900 MHz and 2.45 GHz bands and has the right hand circularly polarized radiation pattern at all. The measured gains of the antenna are 2.95 dBic at 900 MHz band and 4.6 dBic at 2.45 GHz band.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.10
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• pp.74-79
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• 2010

In this paper, a high gain W-band amplifier is presented using 70 run mHEMT MMIC technology. The length of source feedback line of common-source FET is carefully determined to maximize the gain at a design frequency. Simulation shows that MAG can be increased by 0.8 dB by optimizing the length of this line. In addition, this feedback line changes the input impedance of the common-source FET in a way that the input match can be made easier. In this work, 4-stage amplifier is designed on CPW using the source feedback. The measurement shows the excellent gain performance higher than 22.0 dB across 70~103 GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.658-666
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• 2003

In this paper, we analyzed standard and characteristic of portable microwave digital FPU(Field Pick Up) transmission system in AWGN channel environment as basis step of research about share way of M/W broadcasting relay frequency. And we analyzed system performance through simulator design. Domestic case, digitize progress about broadcasting relay is propeled. Therefore, we wish to utilize to basis data about interference evaluation and domestic broadcasting relay standardization for reassignment of M/W band broadcasting relay frequency.

• International Journal of Advanced Culture Technology
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• v.7 no.4
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• pp.236-241
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• 2019

This paper will read about a multichannel frequency-modulated continuous wave (FMCW) radar sensor with switching transmit (TX) antennas is developed at W-band. To achieve a high angular resolution, a uniform linear array consisting of 5 switching-TX and 12 receive (RX) antennas is employed with the digital beamforming technique. The overall radar front-end module comprises a W-band transceiver and TX/RX antennas. A multichannel transceiver module consists of 5 up-conversion and 12 down-conversion channels, where one of the TX channels is sequentially switched ON. For developing transmitter, we developed an HPA (high power amplified) MMIC chip for W-band radar system and fabricated a transmitter module using this chip. In order to develop the W-band transmitter, we analyzed the important antenna transition structure from HPA MMIC line to W/G (Waveguide)antenna via M/S(microstrip) and fabricated it with 5 transmission channels. As a result, the output power of the transmitter was within 1 dB of the error range after analysis and measurement under normal temperature and environmental conditions.