• Journal of Institute of Control, Robotics and Systems
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• v.13 no.9
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• pp.856-860
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• 2007

This paper presents a robust tracking controller design method for the track-following system of an optical recording device. A tracking loop gain adjustment algorithm is introduced to accurately estimate the tracking vibration quantity in spite of the uncertainties of the tracking actuator. A minimum tracking open-loop gain is calculated by the estimated tracking vibration quantity and a tolerable limit of tracking error. A robust tracking controller is designed by considering a robust $H_\infty$ control problem with the weighting function of a slightly larger gain than the minimum tracking open-loop gain. The proposed controller design method is applied to the track-following system of an optical recording device and is evaluated through the experimental result.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.5 s.98
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• pp.578-585
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• 2005

In this paper, we present a schematic method estimating the tracking vibration quantity occurring in the track-following system of an optical recording device. A tracking loop gain adjustment algorithm is introduced to estimate accurately the tracking vibration quantity in spite of the uncertainties of the tracking actuator, Accordingly, the tracking vibration quantity can be estimated from the tracking error, the controller output, the nominal actuator model, and a compensated gain. An optimal tracking controller can be designed from a minimum tracking open-loop gain calculated by the estimated tracking vibration quantity The proposed vibration quantity estimation and controller design method are applied to the track-following system of an optical recording device and are evaluated through the experimental result.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.9
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• pp.805-812
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• 2007

This paper present a robust controller design method based on the estimation of velocity disturbance to construct a robust fine seek control system. A loop gain adjustment algorithm is introduced to accurately estimate the velocity disturbance in spite of the uncertainties of fine actuator. A weighting function is optimally selected from a minimum fine seek open-loop gain, calculated by estimating the velocity disturbance. A robust fine seek controller is designed by considering a robust $H_{\infty}$ control problem using the weighting function. The proposed controller design method is applied to the fine seek control system of a DVD rewritable drive and is evaluated through the experimental results.

• International Journal of Control, Automation, and Systems
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• v.5 no.3
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• pp.243-250
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• 2007

This paper presents a systematic method of estimating a velocity disturbance occurring in the fine seek control system of an optical disk drive. A fine seek loop gain adjustment algorithm is introduced to accurately estimate the velocity disturbance in spite of the uncertainties of the fine actuator. The velocity disturbance can be estimated from a measurable velocity, a fine seek controller output, and a compensated fine actuator model. A robust fine seek controller can be designed by considering a minimum fine seek open-loop gain, calculated by the estimated velocity disturbance. The proposed controller design method is applied to the fine seek control system of a DVD rewritable drive and is evaluated through the experimental results.

• 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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.3
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• pp.279-286
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• 2010

In this paper, we provide a robust track-following controller design method for the stable coarse seek control. Due to the inaccurate velocity control during a coarse seek, the shake of fine actuator is generated and thus a gain-up track-following control is required to complete stably the coarse seek. To this end, a loop gain adjustment algorithm is introduced to estimate accurately the shake of fine actuator. A weighting function can be properly selected from a minimum tracking gain-up open-loop gain, calculated from the estimated shake quantity of fine actuator. A robust tracking gain-up controller is designed by considering a robust $H_{\infty}$ control problem using the weighting function. The proposed design method is applied to the coarse seek control system of an optical rewritable drive and is evaluated through the experimental results.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.10
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• pp.988-993
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• 2009

In this paper, we deal with a tracking gain-up controller design problem to control effectively the shake of tracking actuator after a track seek. A minimum tracking gain-up open-loop gain can be calculated by estimating the shake of tracking actuator and a desired transient specification is considered to diminish effectively the shake of actuator. A tracking gain-up controller is designed by considering a robust $H_{\infty}$ control problem with a regional stability constraint. The proposed tracking gain-up controller design method is applied to the track-following system of a DVD recording device and is evaluated through the experimental results.

• Journal of Korea Society of Digital Industry and Information Management
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• v.20 no.2
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• pp.63-74
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• 2024

This Paper presents a resistive wideband fully differential low-noise amplifier (LNA) designed using a noise-cancellation technique for TV tuner applications. The front-end of the LNA employs a cascode common-gate (CG) configuration, and cross-coupled local feedback is employed between the CG and common-source (CS) stages. The moderate gain at the source of the cascode transistor in the CS stage is utilized to boost the transconductance of the cascode CG stage. This produces higher gain and lower noise figure (NF) than a conventional LNA with inductor. The NF can be further optimized by adjusting the local open-loop gain, thereby distributing the power consumption among the transistors and resistors. Finally, an optimized DC gain is obtained by designing the output resistive network. The proposed LNA, designed in SK Hynix 180 nm CMOS, exhibits improved linearity with a voltage gain of 10.7 dB, and minimum NF of 1.6-1.9 dB over a signal bandwidth of 40 MHz to 1 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.475-485
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• 2010

This paper proposes a novel concept for a microstrip resonator that can function as a filter and as an antenna at the same time. The proposed structure consists of an outer ring, an open loop-type inner ring, a circular patch, and three ports. The frequencies where the proposed structure works as a filter and as an antenna, respectively, are determined primarily by the radius of the inner ring and the circular patch. The measured results show that, when the microstrip resonator operates as a filtering device, this filter has about 15.1 % bandwidth at the center frequency of 0.63 GHz and a minimum insertion loss of 1.5 dB within passband. There are three transmission zeros at 0.52 GHz, 1.14 GHz, and 2.22 GHz. In the upper stopband, cross coupling - taking place at the stub of the outer ring - and the open loop-type inner ring produce one transmission zero each. The circular patch generates the dual-mode property of the filter and another transmission zero, whose location can be easily adjusted by altering the size of the circular patch. The proposed structure works as an antenna at 2.7 GHz, showing a gain of 3.8 dBi. Compared to a conventional patch antenna, the proposed structure has a similar antenna gain. At the resonant frequencies of the filter and the antenna, high isolation(less than -25 dB) between the filter port and the antenna port can be obtained.

• 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.55-64
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• 2006

This work proposes a calibration-free 14b 70MS/s 0.13um CMOS ADC for high-performance integrated systems such as WLAN and high-definition video systems simultaneously requiring high resolution, low power, and small size at high speed. The proposed ADC employs signal insensitive 3-D fully symmetric layout techniques in two MDACs for high matching accuracy without any calibration. A three-stage pipeline architecture minimizes power consumption and chip area at the target resolution and sampling rate. The input SHA with a controlled trans-conductance ratio of two amplifier stages simultaneously achieves high gain and high phase margin with gate-bootstrapped sampling switches for 14b input accuracy at the Nyquist frequency. A back-end sub-ranging flash ADC with open-loop offset cancellation and interpolation achieves 6b accuracy at 70MS/s. Low-noise current and voltage references are employed on chip with optional off-chip reference voltages. The prototype ADC implemented in a 0.13um CMOS is based on a 0.35um minimum channel length for 2.5V applications. The measured DNL and INL are within 0.65LSB and l.80LSB, respectively. The prototype ADC shows maximum SNDR and SFDR of 66dB and 81dB and a power consumption of 235mW at 70MS/s. The active die area is $3.3mm^2$.