• JSTS:Journal of Semiconductor Technology and Science
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• 제9권4호
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• pp.257-265
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• 2009

Recent progress in development of CMOS power amplifiers for mobile terminals is reviewed, focusing first on switching mode power amplifiers, which are used for transmitters with constant envelope modulation and polar transmitters. Then, various transmission line transformers are evaluated. Finally, linear power amplifiers, and linearization techniques, are discussed. Although CMOS devices are less linear than other devices, additional functions can be easily integrated with CMOS power amplifiersin the same IC. Therefore, CMOS power amplifiers are expected to have potential applications after various linearity and efficiency enhancement techniques are used.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.53-54
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• 2011

본 연구에서는 스마트그리드를 위한 양방향 지능형 반도체 변압기의 새로운 회로구성을 제안하고 그 동작과 성능을 분석한 내용에 대해 기술하고 있다. 먼저 PSIM 소프트웨어를 이용한 시뮬레이션을 통해 제안하는 반도체변압기의 회로적인 특성을 다양하게 분석하였고 이를 기반으로 단상, 1900V, 2kVA 반도체변압기를 제작하고 실험을 통해 그 성능을 검증하였다.

• 조명전기설비학회논문지
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• 제18권4호
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• pp.97-103
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• 2004

단상 유도전동기의 기동전류는 정격전류의 3-6배로 전등의 명멸, TV 화면의 산란, 전동기의 절연 열화, 옥내배선의 순간적인 열화 등을 발생시켜 전력손실, 가전제품의 효율저하 및 수명을 단축시키고 있다. 이러한 문제점을 개선하기 위해 본 논문에서는 트라이액과 교류변류기를 사용하여 기동전류를 3.7(%) 감소시키는 방법을 제안하였으며, 또한 반도체 소자를 사용함으로써 수명은 반영구적임을 확인하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 춘계종합학술대회
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• pp.335-339
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• 1999

본 논문에서는 고속의 전력용 반도체를 이용하여 직류-교류 전력변환을 행하는 전압형 PWM 인버터에서 발생하는 영상전압을 억제할 수 있는 회로시스템을 제안한다. 제안된 시스템은 영상전압과 크기가 같고 역위상의 전압을 발생하여 이를 영상전압 억제용 변압기를 거쳐 인버터 출력에 중첩함으로써 부하에 인가되는 영상전압을 억제하였다. 이로 인해 영상전압분에 의해 접지선으로 흐르는 고조파 누설전류의 감소효과를 가져왔고, 이에 대한 타당성을 시뮬레이션을 통하여 확인하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권4호
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• pp.437-444
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• 2015

A high output power voltage controlled oscillator (VCO) in the U-band was implemented using a 65 nm CMOS process. The proposed VCO used a transmission line to increase output voltage swing and overcome the limitations of CMOS technologies. Two varactor banks were used for fine tuning with a 5% frequency tuning range. The proposed VCO showed small variation in output voltage and operated at 51.55-54.18 GHz. The measured phase noises were -51.53 dBc/Hz, -91.84 dBc/Hz, and -101.07 dBc/Hz at offset frequencies of 10 kHz, 1 MHz, and 10 MHz, respectively, with stable output power. The chip area, including the output buffer, is $0.16{\times}0.16mm^2$ and the maximum output power was -0.11 dBm. The power consumption was 33.4 mW with a supply voltage of 1.2-V. The measured $FOM_P$ was -190.8 dBc/Hz.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권1호
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• pp.42-47
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• 2017

This paper proposes a new series-coupled voltage-controlled oscillator (VCO). The proposed VCO consists of four current-reuse Armstrong VCOs (CRA-VCOs) coupled by four transformers. The series-coupling, current-reuse, and Armstrong topologies improve the phase noise performance by increasing the negative-Gm of the VCO core with half the current consumption of a conventional differential VCO. The proposed VCO consumes 6.54 mW at 9.78 GHz from a 1-V supply voltage. The measured phase noise is -115.1 dBc/Hz at an offset frequency of 1 MHz, and the FoM is -186.5 dBc/Hz. The frequency tuning range is from 9.38-10.52 GHz. The core area is $0.49mm^2$ in a $0.13-{\mu}m$ CMOS process.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.611-615
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• 2003

In this paper, a operation characteristics and analysis of the HB(half bridge) inverter for remote plasma system are studied. the remote plasma system is cleaning system for the chemical vapor deposition (CVD) chamber in semiconductor processing. The remote plasma system is powered by the RF generator The main power stage of the RF generator is used for the HB PWM inverter with an low pass filter in the secondary circuit of the transformer. The detailed mode analysis of HB invertor was described. The operation characteristics of Remote Plasma Source are verified by simulation and experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.636-641
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• 1998

In this paper, operation characteristics of the Zero-voltage-Switching(ZVS) mode and Non-Zero-Voltage-Switching (NZVS) mode of the active clamp (ACL) forward converter are compared through the loss analysis. The losses of semiconductor devices, transformer and passive elements of the converter are analyzed and compared for each type of operation mode. In order to verify the validity of the analysis, we have built a 50W ACL forward converter and measured the losses of the converter. From the experiment it is known that the ACL forward converter shows nearly same loss distribution for both of operation modes

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.2039-2041
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• 1998

In this paper, Operation characteristics of the active clamp(ACL) zero-voltage-switching(ZVS) forward converter(FC) and active clamp hard- switching(HS) forward converter are compared with respect to loss analysis. The losses of semiconductor (including conduction losses and switching losses), transformer(containing the core loss and copper loss) and parasitic element of passive element (capacitor, inductor) are measured and compared for each type. For an experiment we have built 50W ACL ZVS-FC and ACL HS-FC, in which the switching frequency is 200kHz, and test it. The experimental results show that both types of operation have nearly same characteristics.

• 대한디지털의료영상학회논문지
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• 제13권1호
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• pp.27-32
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• 2011

The conventional types of X-ray generators were bulky in physical size and heavy in weight, and the control accuracies of the output voltages were not always satisfactory. The high frequency switching inverter and converter technology on power conversion and control systems have been greatly closed up introducing power semiconductor devices. To decreasing the volume and the weight of high voltage transformer, and to stabilize ripple. In this paper, the newly developed x-ray generator in a low cost using duty modulation PWM inverter. This system verify improved performance by stabilize ripple of X-ray tube voltage and compared the reproducibility, linearity and dose in single phase, three phase and PSU.