• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1597_1598
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• 2009

In this paper, the techniques and design focus of flexible gain coltrol of LAN(Low Noise Amplifier) using the TSMC 0.18um CMOS process. The design frequency set up a standard on 2.4GHz that is used in Zigbee system. The design concepts a basic Cascode LNA techniques and a swiching circuit consisted of 4 NMOS of load resistance, which convert the output impedenceby tuning on or off. The result show the gain change by NMOS operated swich. The simulation result is that Gain is 10.23~12.96dB and NF(Noise Figure) is 1.41~1.47dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.900-905
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• 2009

A common drain feedback CMOS wideband LNA with current bleeding and input inductive series-peaking techniques is presented in this paper. DC coupling is adopted between cascode and feedback amplifiers, so that the gain and NF of the LNA can be dynamically controlled by adjusting the bleeding current. The fabricated LNA shows the bandwidth of 2.5 GHz. The high gain mode shows 17.5 dB gain with $1.7{\sim}2.8\;dB$ NF and consumes 27 mW power and the low gain mode has 14 dB gain with $2.7{\sim}4.0\;dB$ NF and dissipates 1.8 mW from 1.8 V supply.

• Journal of Korea Multimedia Society
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• v.6 no.1
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• pp.161-166
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• 2003

This paper presents a high gain LNA for a bluetooth application using 0.25$\mu\textrm{m}$ CMOS technology. The conventional one stage LNA has a low power gain. The presented one stage LNA using a cascode inverter LNA with a voltage reference and without a choke inductor has an improved Power gain. Simulation results of the 2.4GHz designed LNA shows a high power gain of 21dB, a noise figure of 2.2dB, and the power consumption of 255mW at 2.5V power supply.

• ETRI Journal
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• v.28 no.1
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• pp.1-8
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• 2006

A novel all-optical gain-controlled (AOGC) bidirectional amplifier is proposed and demonstrated in a compact structure. The AOGC function using fiber Bragg grating (FBG) pairs controls both directional signals independently, and combinations of optical interleavers and isolators suppress Rayleigh backscattering (RB) noise. The amplifier achieves high and constant gain with a wide dynamic input signal range and low noise figure. The performance does not depend on the input signal conditions, whether static-state or transient signals, or whether there is symmetric or asymmetric data traffic on bidirectional transmission. Transmission comparison experiments between invariable symmetrical and random variable asymmetric bidirectional data traffic verify that the all-optical gain control and bidirectional amplification functions are successfully combined into this proposed amplifier.

• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.444-449
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• 1998

A modal transducer in two-dimensional structure can be implemented by varying the distributed transducer's gain spatially. In this paper, a method based on finite element method is developed for optimizing spatial gain distribution of PVDF transducer to create the modal transducer for specific modes. Using this concept, one can design the modal transducer in two-dimensional structure having arbitrary geometry and boundary conditions. As a practical means for implementing this continuous gain distribution without repoling die PVDF film, the gain distribution is approximated by optimizing gain-weights of interface circuit. The whole spatial area of the PVDF film is divided into several electrode segments and the signals from each segment are properly weighted and summed by interface circuit. This corresponds to the approximation of a continuous function using discrete values. The electrode partition is optimized using the genetic algorithm. Gain-weights are optimized using the simplex search method. A modal sensor for first to fourth modes of aluminum plate is designed using PVDF film with gain-weighted interface circuit. Various lamination angles of PVDF film are taken into consideration to utilize the anisotropy of the PVDF film. Performance of the optimized' PVDF sensor is demonstrated by numerical simulations..

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.4
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• pp.299-303
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• 2011

In this paper, we propose an output feedback controller for a chain of integrators system compensating measurement noise of feedback sensor. Measurement noise makes feedback signals distorted, and results in performance degradation or even system failure. Therefore, we need to design a robust controller to accommodate the possible measurement noise in the feedback information. Our controller is equipped with a gain-scaling factor to reject or minimize the effect of measurement noise in output feedback information. We give a theoretical analysis of the controlled system and illustrate the improved control performance via an example.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.965-968
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• 2016

This paper describes a new speckle noise reduction methode on the sonar image using TVG Filtering and PDF wavelet transform. The speckle noise makes the degrading image to discriminate the various object on the ocean bed. The TVG filter removes the speckle noise by gain with observing the results timely and inductively. The experimental result is that speckle noise is reduced to 90 %. Thus the proposed technique leads the mage recognition to be enhanced in the submarine environment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.257-262
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• 2012

The Ministry of Information-Communication assigned 18~19GHz frequency band for communication of cabins and platform to link between subway/train and it's station. In this paper, we propose wireless transmission devices which are 2 stage hybrid low noise amplifier of 18GHz band and mixer for 18GHz as well to apply for RF receiver. We designed LNA to be noise matched its 1st stage and gain matched for 2nd stage and mixer using $180^{\circ}$ hybrid coupler to suppress the spurious signal. The transistors of 18 GHz LNA and mixer are NE3210S01 of NEC and KMB-N51-1, respectively. As the result of simulation, we get 19.92dB gain and 2.06dB noise figure with LNA and 8.61dB conversion loss with mixer.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1137-1140
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• 2002

A V-band low-noise amplifiers (LNA) based on the Millimeter-wave monolithic integrated circuit (MIMIC) technology were fabricated using high performance 0.1 $\mu\textrm{m}$ $\Gamma$-shaped pseudomorphic high electron mobility transistors (PHEMT＇s), coplanar waveguide (CPW) structures and the integrated process for passive and active devices. The low-noise designs resulted in a two-stage MIMIC LNA with a high S$\sub$21/ gain of 14.9 dB and a good matching at 60 ㎓. 20 dBm of IP3 and 3.9 dB of minimum noise figure were also obtained from the LNA. The 2-stage LNA was designed in a chip size of 2.3 ${\times}$1.4 mm$^2$by using 70 $\mu\textrm{m}$ ${\times}$2 PHEMT’s. These results demonstrate that a good low-noise performance and simultaneously with a high gain performance is achievable with GaAs PHEMT's in the 60 ㎓ band.