• Journal of Advanced Marine Engineering and Technology
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• v.32 no.8
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• pp.1263-1268
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• 2008

In this paper, the low noise power amplifier for GaAs FET ATF-10136 is designed and fabricated with active bias circuit and self bias circuit. To supply most suitable voltage and current, active bias circuit is designed. Active biasing offers the advantage that variations in the pinch-off voltage($V_p$) and saturated drain current($I_{DSS}$) will not necessitate a change in either the source or drain resistor value for a given bias condition. The active bias network automatically sets a gate-source voltage($V_{gs}$) for the desired drain voltage and drain current. Using resistive decoupling circuits, a signal at low frequency is dissipated by a resistor. This design method increases the stability of the LNA, suitable for input stage matching and gate source bias. The LNA is fabricated on FR-4 substrate with active and self bias circuit, and integrated in aluminum housing. As a results, the characteristics of the active and self bias circuit LNA implemented more than 13 dB and 14 dB in gain, lower than 1 dB and 1.1 dB in noise figure, 1.7 and 1.8 input VSWR at normalized frequency $1.4{\sim}1.6$, respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.1
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• pp.98-101
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• 2008

In this paper, we describe the RLG current stabilizer circuit for attitude control in the satellite. The RLG makes use of the Sagnac effect within a resonant of a HeNe laser. The difference between two discharge currents causes one of the gyro bias errors. The theoretical background and current stabilizer are introduced. It is verified that the circuit designed is applicable to the test of input voltage and temperature.

• Journal of the Korean Institute of Telematics and Electronics
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• v.8 no.4
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• pp.7-16
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• 1971

A negative resistance element in the form of current control can be obtained by using a pair transistor circuit. This negative resistance element can be used in the generation of square pulse, and also in the realization of pulse width modulation circuit by superposing signal current on its bias current. The each bias current of pair circuit increases alternatively according to the polarity of the input signal. In order to satisfy this condition, a modified full wave rectification circuit has been adopted for supplying the input signal. Theoritical analysis of pulse times and design guidances for practical modulation circuit parameters are presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1325-1331
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• 1996

In this paper, a new current-memory circuit is proposed that reduces the clock feedthrough(CFT) error voltage causing total harmonic distortion(THD) increment in switched-current(SI) systems. Using PMOS transistor in CMOS complementary, the proposed one reduces output distortion current due to the CFT errorvoltage. A proposed current-memory is designed using a 1.2.mu.m CMOS process anda 1MHz sinusoidal signal having a 68.mu.A amplitude current is applied as input (sampling frequency:20MHz). It hasbeen shown from the simulation that the output distortion current effected by the CFT error voltage is reduced by approximately 10 times the error voltage of conventional one, THD is -57dB in case ofappling 1kHz frequency input signalwith 0.5 peak signal-to-bias current ratio.

• Transactions on Electrical and Electronic Materials
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• v.14 no.4
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• pp.177-181
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• 2013

In this paper, silicon solar cells are analyzed regarding power conversion efficiency by changed capacitance in the depletion region. For the capacitance control in the depletion region of silicon solar cell was applied for 10, 20, 40, 80, 160 and 320 Hz frequency band character and alternating current(AC) voltage with square wave of 0.2~1.4 V. Academically, symmetry formation of positive and negative change of the p-n junction is similar to the physical effect of capacitance. According to the experiment result, because input of square wave with alternating current(AC) voltage could be observed to changed capacitance effect by indirectly method through non-linear power conversion (Voltage-Current) output. In addition, when input alternating current(AC) voltage in the silicon solar cell, changed capacitance of depletion region with the forward bias condition and reverse bias condition gave a direct effect to the charge mobility.

• Journal of the Korean Institute of Telematics and Electronics
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• v.5 no.2
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• pp.8-14
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• 1968

A linear current-pulse discriminator consisting: of a transistor monostable multivibrator and a Si tunnel diode is described. The input currant pulse range is about 50$\mu$A~5.23mA. The measured maximum linearity deviation is $\pm$0.75% in the input current pulse range mentioned above. The pulse resolving ability of the discriminator measured depends upon the bias current through the T, D. ; and, under the reverse bias current of 3mA, the resolving time is 2rs if allow the excess pulse amplitude of 5%. The threshold stability of the discriminator depends mainly upon the stability of the peak current Ip of the T. D. ; and, under the ambient temperature variation from $0^{\circ}C$ to 5$0^{\circ}C$, no bigger threshold variation than the maximum linearity deviation, i. e. $\pm$ 0.75%, was observed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.699-702
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• 2002

A DC current sensor is disclosed in which two pairs of saturable cores are provided so as enclose a conductor carrying a direct current to be measured. On each of the saturable cores, a bias winding, a feedback winding and an output winding are wound. Circuit for detection of an asymmetry in the magnetization current, generated by a reference alternating voltage, in a signal-conditioner. The reference alternating voltage is fed to the respective series circuits such that no resultant induction current is induced in the modulating current. The voltages over the resistor form input signals for two peak value detectors, the strength of the output signal of which represents the degree of asymmetry of magnetization current. This paper describes the development a DC current sensor and its signal-conditioner.

• Journal of Magnetics
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• v.8 no.4
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• pp.160-163
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• 2003

In magnetic flux measurement, output voltage drift of electronic integrator is an essential problem. In this work, we have developed a new kind of Miller type integrator using a sample and hold amplifier. Input bias current was measured and this value was hold in the sample and hold amplifier, after that input bias current of Miller integrator was compensated automatically using the value which holds in the sample and hold amplifier. Developed flux-meter shows the drift of flux-meter are smaller than 10$^{-5}$ Wb/min in full scale of 10$^{-2}$, and we could also measure multi-channel magnetic flux simultaneously.

• Journal of the Korean Magnetics Society
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• v.15 no.6
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• pp.332-335
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• 2005

Output voltage of the flux-meter has always drift due to the input bias current of non-ideal operational amplifier. In this study we have employed a digital sample and hold amplifier which has no voltage drop to compensate drift of the flux-meter automatically. The drift of the developed flux-meter was smaller than $5{\times}10^{-8}\;Wb/s$ for the integration time constant of $RC=10^{-3}$ s.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.289-292
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• 2001

A Novel fully-differential bipolar current-controlled current amplifier(CCCA) for electrically tunable circuit design at current-mode signal processing were designed. The CCCA was consisted of fully-differential subtracter and fully-differential current gain amplifier. The simulation result shows that the CCCA has current input impedance of 0.5 Ω and a good linearity. The CCCA has 3-dB cutoff frequency of 20 MHz for the range over bias current 100$mutextrm{A}$ to 20 ㎃. The power dissipation is 3 mW.