• Title/Summary/Keyword: Nonlinear Capacitance

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A Highly Efficient Broadband Class-E Power Amplifier with Nonlinear Shunt Capacitance

  • Dang-Duy, Ninh;Ha-Van, Nam;Jeong, Daesik;Kim, Dong Hwan;Seo, Chulhun
    • Journal of electromagnetic engineering and science
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    • v.17 no.4
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    • pp.221-227
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    • 2017
  • A new approach to designing a broadband and highly efficient class-E power amplifier based on nonlinear shunt capacitance analysis is proposed. The nonlinear shunt capacitance method accurately extracts optimum class-E power amplifier parameters, including an external shunt capacitance and an output impedance, at different frequencies. The dependence of the former parameter on the frequency is considered to select an optimal value of external shunt capacitor. Then, upon determining the latter parameter, an output matching network is optimized to obtain the highest efficiency across the bandwidth of interest. An analytical approach is presented to design the broadband class-E power amplifier of a MOSFET transistor. The proposed method is experimentally verified by a 140-170 MHz class-E power amplifier design with maximum added power efficiency of 82% and output power of 34 dBm.

Suppression of Leakage Current and Distortion in Variable Capacitance Devices and their Application to AC Power Regulators

  • Katsuki, Akihiko;Oki, Takuya
    • Journal of Power Electronics
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    • v.16 no.1
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    • pp.66-73
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    • 2016
  • The quantity of alternating current (AC) leakage and the value of distortion factor in capacitor currents are discussed with regard to a new power component called variable capacitance device (VCD). This component has terminals for controlling its capacitance. Nonlinear dielectric characteristics are utilized in this device to vary the capacitance. When VCD operates in an AC circuit, the AC leakage from this device through direct current (DC) control voltage source increases according to the conditions of DC control voltage and so on. To solve this problem, we propose techniques for suppressing AC leakage. Although VCD has strong nonlinear characteristics, the current through the capacitor is not distorted significantly. The relations between AC leakage and the distortion in current waveforms are investigated. An application example for an AC power regulator is also introduced to evaluate the distortion in waveforms.

Design of a Highly Efficient Broadband Class-E Power Amplifier with a Low Q Series Resonance

  • Ninh, Dang-Duy;Nam, Ha-Van;Kim, Hyoungjun;Seo, Chulhun
    • Journal of electromagnetic engineering and science
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    • v.16 no.3
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    • pp.143-149
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    • 2016
  • This work presents a method used for designing a broadband class-E power amplifier that combines the two techniques of a nonlinear shunt capacitance and a low quality factor of a series resonator. The nonlinear shunt capacitance theory accurately extracts the value of class-E components. In addition, the quality factor of the series resonator was considered to obtain a wide bandwidth for the power amplifiers. The purpose of using this method was to produce a simple topology and a high efficiency, which are two outstanding features of a class-E power amplifier. The experimental results show that a design was created using from a 130 to 180 MHz frequency with a bandwidth of 32% and a peak measured power added efficiency of 84.8%. This prototype uses an MRF282SR1 MOSFET transistor at a 3-W output power level. Furthermore, a summary of the experimental results compared with other high-efficiency articles is provided to validate the advantages of this method.

Instantaneous Voltage Control of PWM Converters Using Feedback Linearization (궤환선형화 기법을 이용한 PWM 컨버터의 순시전압 제어)

  • 이지명;이기도;이동춘
    • The Transactions of the Korean Institute of Power Electronics
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    • v.4 no.2
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    • pp.175-183
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    • 1999
  • For fast response of the dc output voltage in P\hi1'v1 converter, it is desirable that the relation of power balance of the i input and output terminals is introduced to the system modeling. In this case, controller desi밍1 is not easy since the m model is nonlinear. In this paper, a nonlinear control them${\gamma}$ using input-output feedback linearization is used to solve t the nonlinear problem of the system. By nonlinear control. the voltage transient response can be faster, and it is also p possible to control the output voltage to be constant with smaller output filter capacitance for load disturbance.

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Effect of firing temperature and degree of lamination on microstructure and electrical properties of ZnO-based multilayered ceramic chip varistors (소성온도와 적층수가 ZnO계 적층형 바리스터의 미세구조와 전기적 특성에 미치는 영향)

  • Kim, Chul-Hong;Kim, Jong-Hwa;Kim, Jin-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.08a
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    • pp.126-129
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    • 2003
  • The electrical properties of a ZnO-based multilayered chip varistor (abbreviated as MLV) were studied as functions of firing condition and the degree of lamination. The fundamental varistor characteristics such as nonlinear coefficient and breakdown voltage were independent of the degree of lamination. As the number of the laminated ceramic sheets increased, however, not only the energy handling capability but also the capacitance and the leakage current which are relevant to delayed response to the voltage surge and the pre-breakdown energy loss, respectively, increased. With the increase of firing temperature between $950^{\circ}C$ and $1150^{\circ}C$, both the capacitance and the leakage current of the MLV increased due mainly to the grain growth of ZnO and the volatilization of $BiO_2O_3$. High performance MLVs with clear electrode pattern were obtained at the firing temperature range of $l000{\sim}1050^{\circ}C$ in this experiment.

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A CMOS Stacked-FET Power Amplifier Using PMOS Linearizer with Improved AM-PM

  • Kim, Unha;Woo, Jung-Lin;Park, Sunghwan;Kwon, Youngwoo
    • Journal of electromagnetic engineering and science
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    • v.14 no.2
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    • pp.68-73
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    • 2014
  • A linear stacked field-effect transistor (FET) power amplifier (PA) is implemented using a $0.18-{\mu}m$ silicon-on-insulator CMOS process for W-CDMA handset applications. Phase distortion by the nonlinear gate-source capacitance ($C_{gs}$) of the common-source transistor, which is one of the major nonlinear sources for intermodulation distortion, is compensated by employing a PMOS linearizer with improved AM-PM. The linearizer is used at the gate of the driver-stage instead of main-stage transistor, thereby avoiding excessive capacitance loading while compensating the AM-PM distortions of both stages. The fabricated 836.5 MHz linear PA module shows an adjacent channel leakage ratio better than -40 dBc up to the rated linear output power of 27.1 dBm, and power-added efficiency of 45.6% at 27.1 dBm without digital pre-distortion.

New RF Empirical Nonlinear Modeling for Nano-Scale Bulk MOSFET (나노 스케일 벌크 MOSFET을 위한 새로운 RF 엠피리컬 비선형 모델링)

  • Lee, Seong-Hearn
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.12 s.354
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    • pp.33-39
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    • 2006
  • An empirical nonlinear model with intrinsic nonlinear elements has been newly developed to predict the RF nonlinear characteristics of nano-scale bulk MOSFET accurately over the wide bias range. Using an extraction method suitable for nano-scale MOSFET, the bias-dependent data of intrinsic model parameters have been accurately obtained from measured S-parameters. The intrinsic nonlinear capacitance and drain current equations have been empirically obtained through 3-dimensional curve-fitting to their bias-dependent curves. The modeled S-parameters of 60nm MOSFET have good agreements with measured ones up to 20GHz in the wide bias range, verifying the accuracy of the nano-scale MOSFET model.

Analysis and Performance of the Self Excited Eddy Current Brake

  • Cho, Sooyoung;Jeong, Teachul;Bae, Jaenam;Yoo, Changhee;Lee, Ju
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.459-465
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    • 2017
  • This paper describes a performance analysis of self-excited eddy current brake(SECB). Stator winding of SECB is connected by capacitor instead of voltage source, and SECB's braking force is generated by L-C resonance. SECB has wide range of driving and nonlinear inductance as well. Therefore, it is important to select capacitance based on the value of inductance. This paper discusses about the process of deciding capacitance and the change of resonance frequency based on the inductance change in each speed. Also the braking force was confirmed by the experimental model of SECB.

Frquency Characteristics of Electronic Mixing Optical Detection using APD for Radio over Fiber Network (무선 광파이버 네트웍(RoF)을 위한 APD 광전 믹싱검파의 주파수 특성)

  • Choi, Young-Kyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.7
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    • pp.1386-1392
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    • 2009
  • An analysis is presented for super-high-speed optical demodulation by an avalanche photodiode(APD) with electric mixing. A normalized gain is defined to evaluate the performance of the optical mixing detection. Unlike previous work, we include the effect of the nonlinear variation of the APD capacitance with bias voltage as well as the effect of parasitic and amplifier input capacitance. As a results, the normalized gain is dependent on the signal frequency and the frequency difference between the signal and the local oscillator frequency. However, the current through the equivalent resistance of the APD is almost independent of signal frequency. The mixing output is mainly attributed to the nonlinearity of the multiplication factor. We show also that there is an optimal local oscillator voltage at which the normalized gain is maximized for a given avalanche photodiode.

Inverter air-conditioner Power System using Nonlinear Capacitance

  • Park, Young-Jo;Mun, Sang-Pil;Kim, Young-Mun;Lee, Hyun-Woo;Suh, Ki-Young
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1223-1225
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    • 2003
  • By having the proposed circuit using a smaller one with a small reactor, the output voltage is boosted-up and improves the input of the current waveform. Therefore, we are able to follow the harmonics guidelines. Greater power and efficiency is obtained from the proposed circuit. This also reduces some switching loss and holds the overshooting by using the inverter of eliminated dead-time HPWM which is a non-linear impedance of the circuit to make up the diodes, the capacitance, and the reactor. We compared the conventional PWM inverter and proposed HPWM inverter.

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