• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.1084-1085
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• 2005

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.2127-2130
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• 2008

In this paper, a tunable bandpass filter with mutual inductive coupling circuits is newly designed and demonstrated for UHF TV tuner ranged from Ch.14(473MHz) to Ch.69(803MHz) applications. Conventional HF tuning circuit with an electromagnetic bandpass filter has several problems such as large size, high volume and high cost, since the electromagnetic filter is comprised of several passive components and air core inductors to be assembled and controlled manually. To address these obstacles, peaking chip inductor was newly applied for constructing the mutual inductive coupling circuit. The proposed circuit was newly and optimally designed, since the chip inductor showed lower components Q-value than the air core inductor. A varactor diode has been also used to fabricate the proposed tunable bandpass filter for RF tuning circuit. The fabricated tunable filter exhibited low insertion loss of approximately -3dB, high return loss of below -10dB, and large tuning bandwidth of 330MHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.2
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• pp.403-410
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• 1999

A conventional PID controller has poor performance when it applied to systems with unknown deadzones. To solve this problem, this paper proposes PID controller using two layered-fuzzy logic. The structure of controller is reconstructed with fuzzy compensator and fuzzy tuner on the conventional PID controller. Our proposed control scheme shows superior transient and steady-state performance compared to conventional PID controller. The scheme is robust to variations in deadzone nonlinearities as well as the steady-state gain of the plant. The performance of the developed controller is verified through simulation.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1221-1224
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• 1987

In this paper, we had designed and fabricated the integrated circuit of AM tuner system for car. The very important characteristics of this system need very good sensitivity, selectivity and very strong automatic gain control function. In this system we had designed, maximum sensitivity is about 21dBu, selectivity above 40dB, AGC range above 80dB, etc. We had fabricated this IC using SST standard linear process.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.2
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• pp.16-21
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• 1993

A newly advanced method of characterizing large signal S-parameters of TR using the overall gain of normally operating TR is proposed based on the load pull method which gives the matching network only. Large signal S-parameters of TR are characterized from the circuit which consists of TR and 3dB Coupler Tuners at the input and output ports, and which is B class biased with 0dBminput signal. Amplifier can be designed to have 8.5dB gain at 770MHz using the calculated large signal S-parameters with the resulting gain of 8.786dB.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.121-126
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• 1996

In this paper an MMIC VCO which can be used in a double conversion TV tuner is designed, fabricated and measured. The VCO is designed using the small signal method and fabricated using ETRI GaAs MMIC foundry. The 3x200$\mu$m gate width MESFET with 1$\mu$m gate length is used for an active device and MIM capacitors, spiral inductors, thin film resitors are used as passive elements. The VCO has output power of 10.95dBm at 1955 MHz with 5V bias voltage and 4V tuning voltage. The oscillation frequency change form 1947 MHz to 1964 MHz is obtaine dby an external varactor diode connected to the gate with a tuning voltage from 0 V to 6V.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.621-623
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• 1999

In this paper, Model following PID control system, which is combined PID controller with Model Reference Adaptive Controller, is proposed. To decrease complex and much calculation which is produced in tuning process, the tuning method of parameter with fuzzy algorithm is introduced. Fuzzy algorithm isn't used in the form of controller generally much used, but tuner. Experimental results show that proposed controller has the PID parameter be tuned by fuzzy algorithm. Therefore, We expect model following PID to be operated in the real-time control.

• The Journal of Engineering Research
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• v.3 no.1
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• pp.171-180
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• 1998

The low cost fiber ring laser can be tuned by controlling polarization states within the loop. In this paper, we investigate its operating principle and verify the performance through an experiment. This ring laser consists of a polarization controller and an intracavity polarizer for the wavelength tuner and semiconductor optical amplifier for the gain medium. It is seen that the lasing wavelength may be tuned through the range of 1540~1560 nm as a polarization controller and a polarizer are adjusted.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.185-185
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• 2008

This paper describes the broadband SDC (Single-ended to Differential Converter) for Digital Video Broadcasting-Satellite $2^{nd}$ edition (DVB-S2) receiver tuner IC. It is fabricated by using $0.18{\mu}m$ CMOS process. In order to obtain high linearity and low phase mismatch, the broadband SDC (Single-ended to Differential Converter) is designed with current mirror structure and cross-coupled capacitor and current source binding differential structure at VDD. The simulation result of SDC shows IIP3 of 11.9 dBm and IIP2 of 38 dBm. It consumes 5mA current with 2.7V supply voltage.

• ETRI Journal
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• v.33 no.6
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• pp.969-972
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• 2011

This letter presents a CMOS RF front-end operating in a subthreshold region for low-power Band-III mobile TV applications. The performance and feasibility of the RF front-end are verified by integrating with a low-IF RF tuner fabricated in a 0.13-${\mu}m$ CMOS technology. The RF front-end achieves the measured noise figure of 4.4 dB and a wide gain control range of 68.7 dB with a maximum gain of 54.7 dB. The power consumption of the RF front-end is 13.8 mW from a 1.2 V supply.