• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.5
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• pp.319-326
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• 2019

The use of high-voltage gain converters is essential for distributed power generation systems with renewable energy sources, such as fuel and solar cells, due to their low-voltage characteristics. In this study, a novel high-voltage gain non-isolated buck boost converter topology is proposed to cope with the need of a high-voltage conversion ratio without the transformer for the renewable energy sources. Given that the proposed topology utilizes the cascode structure, the voltage gain and the efficiency are higher than those of other conventional non-isolated converters. To demonstrate the feasibility of the proposed topology, the operation principle is presented, and the steady-state characteristics are analyzed in detail. The validity of the proposed converter is verified by experiments with a 400 W prototype converter.

• Journal of Power Electronics
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• v.19 no.3
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• pp.676-690
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• 2019

This paper presents a switched capacitor (SC) based bidirectional dc-dc converter topology for high voltage gain applications. The proposed converter is able to operate with multiple integral voltage conversion ratios based on user input. The architecture of a user-friendly, inductor-less multi-voltage-gain bidirectional dc-dc converter is proposed in this study. The inductor-less or magnetic-less design of the proposed converter makes it effective in higher temperature applications. Furthermore, the proposed converter has a reduced component count and lower voltage stress across its switches and capacitors when compared to existing SC converters. An output impedance analysis of the proposed converter is presented and compared with popular existing SC converters. The proposed converter is simulated in the OrCAD PSpice environment and the obtained results are presented. A 200 W hardware prototype of the proposed SC converter has been developed. Experimental results are presented to validate the efficacy of the proposed converter.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.231-238
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• 2019

The objective of this study is to understand the relationship between type of advertising and brand attachment. We divide advertising frame into loss and gain frame and examine the effect on brand attachment, The effect of unique advertising on brand attachment and the effects of interaction effects on brand attachment were examined. The results showed that the effect of the loss and gain frame on brand attachment was statistically significant. It also showed that unique advertising had positive effect on brand attachment. Moreover, the interaction effects of the advertising frame and the uniqueness of advertising have been shown to affect brand attachment. That is, the more emphasis on gain in advertising frame and the more unique advertising, the more effective on brand attachment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.6
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• pp.853-856
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• 2021

In this paper, a low noise amplifier having high gain and low noise by using input and inter stage matching circuits has been designed. A current-reused two-stage common-source topology is adopted, which can obtain high gain and low power consumption. Deterioration of noise characteristics according to the source inductive degeneration matching is compensated by adopting additional matching circuits. Moreover trade-offs among noise, gain, linearity, impedance matching, and power dissipation have been considered. In this design, 0.18-mm CMOS process is employed for the simulation. The simulated results show that the designed low noise amplifier can provide high power gain and low noise characteristics.

• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.307-314
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• 2021

Recently, positively asymmetric binary pulse amplitude modulation (2PAM) has been proposed to improve the bit error rate (BER) performance of the weak channel gain user, with a tolerable BER loss of the strong channel gain user, for non-orthogonal multiple access (NOMA). However, the BER loss of the stronger channel gain user is inevitable in such positively asymmetric 2PAM NOMA scheme. Thus, we propose the negatively asymmetric 2PAM NOMA scheme. First, we derive closed-form expressions for the BERs of the negatively asymmetric 2PAM NOMA. Then, simulations demonstrate that for the stronger channel gain user, the BER of the proposed negatively asymmetric 2PAM NOMA improves, compared to that of the conventional positively asymmetric 2PAM NOMA. Moreover, we also show that for the weaker channel gain user, the BER of the proposed negatively asymmetric 2PAM NOMA is comparable to that of the conventional positively asymmetric 2PAM NOMA, over the power allocation range less than about 10 %.

• Journal of Sensor Science and Technology
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• v.33 no.1
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• pp.12-17
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• 2024

Floating inverter amplifiers (FIAs) have recently garnered considerable attention owing to their high energy efficiency and inherent resilience to input common-mode voltages and process-voltage-temperature variations. Since the voltage gain of a simple FIA is low, it is typically cascaded or cascoded to achieve a higher voltage gain. However, cascading poses stability concerns in closed-loop applications, while cascoding limits the output swing. This study introduces a gain-enhanced FIA that features cross-coupled body biasing. Through simulations, it is demonstrated that the proposed FIA designed using a 28-nm complementary metal-oxide-semiconductor technology with a 1-V power supply can achieve a high voltage gain (> 90 dB) suitable for dynamic open-loop applications. The proposed FIA can also be used as a closed-loop amplifier by adjusting the amount of positive feedback due to the cross-coupled body biasing. The capability of achieving a high gain with minimum-length devices makes the proposed FIA a promising candidate for low-power, high-speed sensor interface systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.6
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• pp.835-840
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• 1993

In this paper a FET mixer is designed realized by small-signal S-parameter using microwave CAD, LINMIC + at Ku-band. The mixer has conversion gain 9.88dB at 14GHz RF, 1GHz IF, and + 1dBm LO imput. The maximum conversion gain is obtained 11.71dB at 1.1GHz. The result shows that the FET mixer does not need pre-and/or IF amplifier. The mixer maintains the desired conversion gain with low LO power level. The conversion gain of the mixer is higher than the available gain of a amplifier, which is experimentally verified.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.6
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• pp.607-614
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• 2013

In this study, effect of the sensor gain error is theoretically analyzed and simulated when mixed sequential two-prove method(MTPM) is applied for the precision measurement of straightness error of a linear motion table. According to the theoretical analysis, difference of the gain errors between two displacement sensors increases measurement error dramatically and alignment error of the straightedge is also amplified by the sensor gain difference. On the other hand, if the gain errors of the two sensors are identical, most of error terms are cancelled out and the alignment error doesn't give any influence on the measurement error. Also the measurement error of the straightness error is minimized compared with that of the straightedge's form error owing to close relationship between straightness error and angular motion error of the table in the error terms.

• Journal of Power Electronics
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• v.14 no.1
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• pp.82-91
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• 2014

This paper proposes a compensation algorithm for the analog rotor position errors caused by nonideal sinusoidal encoder output signals including offset and gain errors. In order to achieve a much higher resolution, position sensors such as resolvers or incremental encoders can be replaced by sinusoidal encoders. In practice, however, the periodic ripples related to the analog rotor position are generated by the offset and gain errors between the sine and cosine output signals of sinusoidal encoders. In this paper, the effects of offset and gain errors are easily analyzed by applying the concept of a rotating coordinate system based on the dq transformation method. The synchronous d-axis signal component is used directly to detect the amplitude of the offset and gain errors for the proposed compensator. As a result, the offset and gain errors can be well corrected by three integrators located on the synchronous d-axis component. In addition, the proposed algorithm does not require any additional hardware and can be easily implemented by a simple integral operation. The effectiveness of the proposed algorithm is verified through several experimental results.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1295-1298
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• 2003

The steam generator level in a PWR is very difficult to control particularly at low power. And the constant control gain and time value are not adaptive in steam generator level controller. In normal operation constant control gain and time value have no problem. But there is problem at low power. So variable control gains based on the temperature are required. The best control gain is decided by the experienced knowledge. A fuzzy gain tuner is used for the gain tuning. In the design of fuzzy gain-tuner processing, the experienced knowledge is employed for making fuzzy rules.