• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.731-732
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• 2010

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.299-302
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• 1999

An analog implementation of space vector PWM is proposed in this paper. It is shown that a space vector PWM can be implemented by adding a zero sequency voltage to reference voltage of triangle comparison PWM. The proposed scheme is implemented by six diodes and, an operational amplifier circuit and, a few resistors.

• 한국재료학회지
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• 제3권1호
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• pp.28-32
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• 1993

Si기판상에 Ni 박막 저항체를 형성하여 hot wire anemometer형 흐름측정 소자를 제작하고 이의 특성을 평가하여 보안ㅆ다. 니켈 박박 저항체의 온도계수는 박막의 두께가 얇아짐에 따라 감소하였으며, 제작된 흐름센서의 감ㅁ도는 111.3${\mu}$W/(${\ell}$ pm$)^{1/2}$, 동적인 응답시간은 수 십초 정도로 평가되었다.

• ETRI Journal
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• 제25권1호
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• pp.19-24
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• 2003

This paper describes the performance of a Ku-band 5-bit monolithic phase shifter with metal semiconductor field effect transistor (MESFET) switches and the implementation of a ceramic packaged phase shifter for phase array antennas. Using compensation resistors reduced the insertion loss variation of the phase shifter. Measurement of the 5-bit phase shifter with a monolithic microwave integrated circuit demonstrated a phase error of less than $7.5{\circ}$ root-mean-square (RMS) and an insertion loss variation of less than 0.9 dB RMS for 13 to 15 GHz. For all 32 states of the developed 5-bit phase shifter, the insertion losses were $8.2{\pm}1.4$dB, the input return losses were higher than 7.7 dB, and the output return losses were higher than 6.8 dB for 13 to 15 GHz. The chip size of the 5- bit monolithic phase shifter with a digital circuit for controlling all five bits was 2.35 mm ${\times}$1.65 mm. The packaged phase shifter demonstrated a phase error of less than $11.3{\circ}$ RMS, measured insertion losses of 12.2 ${\pm}$2.2 dB, and an insertion loss variation of 1.0 dB RMS for 13 to 15 GHz. For all 32 states, the input return losses were higher than 5.0 dB and the output return losses were higher than 6.2 dB for 13 to 15 GHz. The size of the packaged phase shifter was 7.20 mm${\times}$ 6.20 mm.

• JSTS:Journal of Semiconductor Technology and Science
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• 제10권4호
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• pp.309-315
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• 2010

A fully-differential low-voltage low-power electrocardiogram (ECG) amplifier by using the nonfeedback PMOS pseudo-resistors is proposed. It consists of two operational-transconductance amplifiers (OTA) in series (a preamplifier and a variable-gain amplifier). To make it insensitive to the gate leakage current of the OTA input transistor, the feedback pseudo-resistor of the conventional ECG amplifier is moved to input branch between the OP amp summing node and the DC reference voltage. Also, an OTA circuit with a Gm boosting block without reducing the output resistance (Ro) is proposed to maximize the OTA DC gain. The measurements shows the frequency bandwidth from 7 Hz to 480 Hz, the midband gain programmable from 48.7 dB to 59.5 dB, the total harmonic distortion (THD) less than 1.21% with a full voltage swing, and the power consumption of 233 nW in a 0.13 ${\mu}m$ CMOS process at the supply voltage of 0.7 V.

• The Korean Journal of Ceramics
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• 제2권1호
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• pp.33-38
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• 1996

In thick film resistors, the characteristics of the frit and the reaction between glass frit and conductor material play an important role for their electrical properties. In this study, various glass frits in the system of $60RO{\cdot}20SiO_2$ $15B_2O_3{\cdot}5Al_2O_3$(RO=PbO, ZnO, CdO; mole%) were mixed with $RuO_2$ and coated on 96% alumina substrate. Only the glass frit containing PbO was reacted with $RuO_2$in$RuO_{2+}$-thick film resistor and produced the new crystalline phase of $Pb_2Ru_2O_{65}$. Their electrical resistivities strongly depend on the amount of $Pb_2Ru_2O_{65}$ crystalline phase obtained, which varied with firing temperature. The sheet resistivities of these resistors were varied from $10^3\; to\; 10^6\;{\Omega}/{\Box}$ depending on heat treatment, and the absolute value of TCR was decreased as the heat treatment temperature increaed. However, $RuO_2$ did not reacted with the glass frits containing ZnO nor CdO, and the resulting showed very high sheet resistivities.

• ETRI Journal
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• 제36권1호
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• pp.116-123
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• 2014

In this paper, a novel unequal broadband out-of-phase power divider (PD) is presented. Double-sided parallel-strip lines (DSPSLs) are employed to achieve an out-of-phase response. Also, an asymmetric dual-band matching structure with two external isolation resistors is utilized to obtain arbitrary unequal power division, in which the resistors are directly grounded for heat sinking. A through ground via (TGV), connecting the top and bottom sides of the DSPSLs, is used to short the isolation components. Additionally, this property can efficiently improve the broadband matching and isolation bandwidths. To investigate the proposed divider in detail, a set of design equations are derived based on the circuit theory and transmission line theory. The theoretical analysis shows that broadband responses can be obtained as proper frequency ratios are adopted. To verify the proposed concept, a sample divider with a power division of 2:1 is demonstrated. The measured results exhibit a broad bandwidth from 1.19 GHz to 2.19 GHz (59.2%) with a return loss better than 10 dB and port isolation of 18 dB.

• 센서학회지
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• 제18권2호
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• pp.147-153
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• 2009

A thermal flow sensor has been fabricated and characterized, consisting of a center resistive heater surrounded by two upstream and one downstream temperature sensing resistors. The heater and temperature sensing resistors are fabricated from nitrogen-doped(n-type) polycrystalline silicon carbide(poly-SiC) deposited by LPCVD(low pressure chemical vapor deposition) on LPCVD silicon nitride films on a Si substrate. Cavities were etched into the Si substrate from the front side to create suspended silicon nitride membranes carrying the poly-SiC elements. One upstream sensor is located $50{\mu}m$ from the heater and has a sensitivity of $0.73{\Omega}$/sccm with ${\sim}15\;ms$ rise time in a dynamic range of 1000 sccm. N-type poly-SiC has a linear negative temperature coefficient and a TCR(temperature coefficient of resistance) of $-1.24{\times}10^{-3}/^{\circ}C$ from room temperature to $100^{\circ}C$.

• 센서학회지
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• 제26권5호
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• pp.331-337
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• 2017

A readout circuit for a tactile sensor pad based on force sensing resistors was proposed, which was composed of an analog signal conditioning circuit and a digital circuit with a microcontroller. The conventional signal conditioning circuit has a dc offset voltage in the output signal, which results from the reference voltage applied to the FSR devices. The offset voltage reduces the dynamic range of the circuit and makes it difficult to operate the circuit under a low voltage power supply. In the proposed signal conditioning circuit, the dc offset voltage was removed completely. The microcontroller with A/D converter and D/A converter was used to enlarge the measurement range of pressure. For this, the microcontroller adjusts the FSR reference voltage according to the resistance magnitude of FSR under pressure. The operation of the proposed readout circuit which was connected to a tactile sensor pad with $5{\times}10$ FSR array was verified experimentally. The experimental results show the proposed readout circuit has the wider measurement range of pressure than the conventional circuit. The proposed circuit is suitable for low voltage and low power applications.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.215-220
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• 1990

A.C. impedance properties of $RuO_2$ based thick film resistors which having different resistivity value (DuPont 1721 : $100{\Omega}$/ sq., 1741 : $10K{\Omega}$/sq.) were investigated using by impedance analyzer. In case of lower resistivity 1721 system, the complex impedance was composed nearly R component for all speciman sintered at above $600^{\circ}C$, and the frequency dependancy on impedance was not affected very much up to 5MHz and again gradually increase with increasing the frequency. In case of higher resistivity 1741 resistor system, impedance properties were very depandant on sintering temperature. When sintering temperature was $600^{\circ}C$, the complex impedance plot shows a vertical line, which correspond to lone capacitance equivalant circuit, and the impedance linearly decreased with increasing frequency. In case of speciman sintered at $700-900^{\circ}C$, the complex impedance plot shows semi-circular are correspond to a lumped RC combination, and the impedance shows constant value to 5MHz, again decreased with increasing frequency. But the complex impedance behavior of speciman sintered at $1000^{\circ}C$ was shows the equivalent circuit correspont to parallel combined LCR component, and the impedance was not varied with frequency.