• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.8
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• pp.784-789
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• 2011

In this paper, a tunable integrated transmitter leakage canceller based on an autotransformer for ultra-high-frequency (UHF) RFID readers is presented. The proposed TX leakage canceller consists of an autotransformer, a digital tuning capacitor, a voltage controlled tuning resistor, and a compensating amplifier, and it is designed using 0.13 ${\mu}m$ 1-poly 6-metal RF CMOS process. The simulation results show that the proposed structure has over 55 dB rejection characteristic between a transmitter and a receiver and a 2.5 dB of the RX insertion loss. The TX leakage canceller can be digitally tuned from 825 MHz to 985 MHz with the tuning capacitor and it can be fully integrated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.904-908
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• 2002

In this paper, we propose a 4-coupled ferroelectric-based meander-type microstrip-line tunable phase shifter which has less than 2dB of insertion loss (IL) and larger than 10dB of return loss (RL)over 13~170Hz .Particularly at 15GHz, the differential phase shift (DPS) is observed to be $89{\circ}$ at zero bias and it increases up to $115{\circ}$ when 150V is applied. This indicates a DPS tunability of $26{\circ}$.

• Natural Product Sciences
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• v.14 no.1
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• pp.37-46
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• 2008

From the 70% EtOH extract of the roots of Astragalus membranaceus (Leguminosae), fifteen saponins were isolated and identified as astragaloside I (1), isoastragaloside II (2), astragaloside II (3), agroastragaloside I (4), cyclogaleginoside B (5), cycloaraloside A (6), brachyoside B (7), agroastragaloside II (8), astragaloside III (9), astragaloside IV (10), astramembranoside A (11), astramembranoside B (12), cylocanthoside E (13), cyclounifolioside B (14) and azukisaponin V methyl ester (15) by spectroscopic methods. Ten compounds 1 - 3, 5 - 7, 9 - 11 and 14 have cycloastragenol as an aglycon, and four compounds 4, 8 , 12, and 13 have cyclocanthogenin as an aglycon. The hairy roots of A. membranaceus were shown to produce previously unreported cycloartane-type saponins such as agroastragalosides I (4) and II (8) and cycloastragenol $3-O-{\beta}-D-xyloside$ (5), together with the known saponins. This is the first report of these saponins (4, 5, and 8) from the intact plant. Although the occurrence of the oleanane-type triterpene saponin, azukisaponin V methyl ester (15), in Astragalus plants has been demonstrated by others, this is the first report of the azukisaponin V methyl ester (15) from the Astragalus plants.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.126-134
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• 1982

When $^{14}C-2$, 6-Diethylaniline (2, 6-DEA) was incubated aerobically in soil, $^{14}CO_2$ evolved from non-sterile soil A and B was 6.5 and 10.1%, respectively, in the 21st week. Methanol could extract 3.1 and 13.5% of the radioactivity from soil A and B, respectively, 2, 6-Diethylacetanilide was detected as a degradation product in soil. Chaetomium globosum produced 2, 6-diethyl-p-benzoquinone as a degradation product in pure culture. A possible pathway was proposed to include p-hydroxylation of 2, 6-DEA, formation of quinoneimine, and the subsequent hydrolysis with the release of ammonia.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2332-2337
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• 2012

In this paper, a blind decision feedback algorithm is proposed based on the ideas that the derivative of information potential for constant modulus errors stays relatively undisturbed even when large output differences are induced by severe channel distortions and this property can prevent the error propagation that is one of the main problems in decision feedback structures. From the simulation results of the steady state MSE, the proposed blind equalizer algorithm with decision feedback has yielded about 3 dB performance enhancement in the channel model without spectrum nulls and above 9 dB in severe channel characteristics with spectrum nulls.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.245-252
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• 2018

In this paper, the dual band circular polarization patch antenna was designed by using band rejection characteristics of CSRR structure for geostationary satellites. A quadrangular CSRR structure was etched on the ground at the rear of the patch antenna's feed to obtain band rejection characteristics in between the receiving frequency band(1525~1559MHz) and transmission band(1626.5~1660.5MHz), and the corner of the patch antenna was truncated to enable circular polarization. It was confirmed that the resonant frequency of the patch antenna differs according to the size anc location of the CSRR and cirular polarization characteristics with simulation and measurement results. Measurement results shows the gain of about 0.2dB and 1.5dB in the TX and RX band.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.255-259
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• 1986

The aflatoxin production by Aspergillus ATCC 15517 decreased in the mixed culture with Aspergillus awamori, Aspergillus kawachii, Aspergillus niger, Aspergillus oryzae, or with Aspergillus shirousamii to 1.3%, 13.8%, 1.3%, 0.7%, or 38.5% of that of monoculture respectively. These koji molds degraded $75%{\sim}100%$ of added aflatoxin $B_1\;(791{\mu}g/50ml\;YES medium)$. A. awamori secreted during growth aflatoxin degrading factor(s) which was heat-labile. The degraded aflatoxin by the factor(s) showed no toxicity against Bacillus megaterium NRRL B-1368.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.511-519
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• 2016

This paper proposes a CMOS 6-bit phase shifter with low RMS phase and amplitude errors for an X-band phased array antenna. The phase shifter combines a switched-path topology for coarse phase states and a switch-filter topology for fine phase states. The coarse phase shifter is composed of phase shifting elements, single-pole double-throw (SPDT), and double-pole double-throw (DPDT) switches. The fine phase shifter uses a switched LC filter. The phase coverage is $354.35^{\circ}$ with an LSB of $5.625^{\circ}$. The RMS phase error is < $6^{\circ}$ and the RMS amplitude error is < 0.45 dB at 8-12 GHz. The measured insertion loss is < 15 dB, and the return losses for input and output are > 13 dB at 8-12 GHz. The input P1dB of the phase shifter achieves > 11 dBm at 8-12 GHz. The current consumption is zero with a 1.2-V supply voltage. The chip size is $1.46{\times}0.83mm^2$, including pads.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1287-1292
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• 2012

In this paper, a dual polarization patch antenna operates at the wide bandwidth of 1.525GHz~1.665GHz was designed and fabricated. To obtain the wide bandwidth and high gain, increased height of air floor from GND was applied, and to get wide band axial ratio and high gain, parasitic patch was applied. The simulation and measurement showed good agreements, the VSWR was less than 1.9 at the frequency bandwidth, the return loss was less than -10dB, and the LHCP(Left Hand Circular Polarization) and RHCP(Right Hand Circular Polarization) isolation was less than -13dB at the frequency bandwidth.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.53-57
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• 2017

This paper proposes a 401MHz-406MHz low noise amplifier for MedRadio applications. The proposed low noise amplifier adopts a common gate amplifier topology using current reuse gm-boosting technique. The proposed low noise amplifier shows better performance of voltage gain and noise figure than the conventional gm-boosted common gate amplifier in the same power consumption. The proposed current-reuse gm-boosted low noise amplifier achieves a voltage gain of 22 dB, a noise figure of 2.95 dB, and IIP3 of -17 dBm while consuming $170{\mu}W$ from a 0.5 V supply voltage in $0.13{\mu}m$ CMOS process.