• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.3
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• pp.52-59
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• 1997

Design and performance of principal four ICs for the 10-Gb/s optical communication system are presented. AlGaAs/GaAs HBTs are basic devices to implement a laser diode driver, apre-amplifier, and a limiting amplifier, and GaInP/GaAs HBTs are used for an AGC amplifier. We fbricated 11.5-GHz LD driver, a pre-amplifier, and a limiting amplifier, an dGaInP/GaAs HBTs are used for an AGC amplifier. We fabricated LD deriver, 10.5 GHz pre amplifier, 7.2 GHz AGC amplifier, and 10.3 GHz limiting amplifier, optimized circuit design and the stabilized MMIC fabrication process.

• Journal of Electrical Engineering and information Science
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• v.2 no.6
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• pp.197-201
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• 1997

To realize 10-Gbit/s optical transmission systems, we designed and fabricated a limiting amplifier with extremely high operation frequencies over 10-GHz using AlGaAs/GaAs heterojunction bipolar transistors (HBTs), and investigated their performances. Circuit design and simulation were performed using SPICE and LABRA. A discrete AlGaAs/GaAs HBT with the emitter area of 1.5${\times}$10$\mu\textrm{m}$$^2$, used for the circuit fabrication, exhibited the cutoff frequency of 63GHz and maximum oscillation frequency of 50GHz. After fabrication of MMICs, we observed the very wide bandwidth of DC∼15GHz for a limiting amplifier from the on-wafer measurement. Ceramic-packaged limiting amplifier showed the excellent eye opening, the output voltage swing of 750mV\ulcorner, and the rise/fall time of 40ps, measured at the data rates of 10-Gbit/s.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.521-522
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• 2008

This paper presents fully integrated low power consumption limiting amplifier. The proposed limiting amplifier is employed folded cascode structure with source degeneration output stage. This proposed structure demands few transconductance than conventional structure. It can be dramatically decrease current consumption. The total power consumption is only $96.5\;{\mu}W$ under a 1.8 V supply voltage in 9.5 dB limited gain condition. It was designed in using $0.18\;{\mu}m$ CMOS technology.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.15-22
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• 1997

A 10Gbit/s limiting amplifier IC for optical transmission system was implemented with AlGaAs HBT (heterojunction bipolar transistor) technology. HBTs with 2x10.mu. $m^{2}$ and 6x20.mu. $m^{2}$ emitter size were used. The HBT structures are based on metal-organic chemical vapor deposition (MOCVD) epitxy and employ a mesa structure with self-aligned emitter/base and sidewall dielectric passivation. IC was designed to support differnetial input and output. Small signal performance of the packaged IC showed 26dB gain and $f_{3dB}$ of 8GHz. A single ouput has 800m $V_{p-p}$ swing with more than 26dB dynamic range. The performance of the limiting amplifier was verified through single mode fiber320km transmission link test.est.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3124-3126
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• 2000

The application of IR(Infrared) communication is very wide and IR receiver has become a standard of home entertainment. A preamplifier with single 5V supply was designed for IR receiver IC. To operate at long distance, receiver IC should have high gain and low noise characteristic. To provide constant output signal magnitude, independent of transciever distance, gain limiting stage is needed. And to cut-off DC noise component effectively, large resistance and capacitance are required. Transimpedance type preamplifier, and diode limiting amplifier, and current limiting amplifier were designed. It is another function of current limiting amplifier that transforms single input signal to differential output signal. Using AMS BiCMOS model, both BJT version and MOS version was designed. Total power consumption is O.lmW, and IC size is $0.3mm^2$

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.454-455
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• 2018

The impedance of an underwater acoustic transducers constituting a multi-channel array structure could be changed in real time by various transmission modes. A power amplifier for driving the transducers usually use a voltage control method, so the transducer and power amplifier may be damaged by over-power due to changeable load conditions. Therefore, the drive controller of the power amplifier should have the function of limiting the power. This paper propose the new voltage control method for limiting the driving power of transducers with variable impedance characteristics.

• Journal of IKEEE
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• v.14 no.4
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• pp.283-290
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• 2010

This study is on the design of 10Gbps CMOS receiver circuits for fiber-optic communication. The receiver is made up of a photodiode, a transimpedance amplifier, a limiting amplifier, an equalizer, a clock and data recovery loop circuit, and a demultiplexer or demux with some auxiliary circuits including I/O circuits. Various wideband or high-speed circuit techniques are harnessed to realize a feasible, effective, and reliable receiver for a SONET fiber-optic standard, OC-192.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.10
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• pp.9-15
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• 2009

In this paper, we invented a new structure of fast ATC(Automatic Threshold Control) circuit. Using the structure we made a new burst-mode limiting amplifier with fast ATC function using commercial $0.8{\mu}m$ BiCMOS technology. It's ATC function worked so fast that even the first bit of burst-data could be detected, which confirmed that the new structure was useful for fast ATC. However, in the beginning of a burst, distortions in duty-cycle occurred and increased up to 59% of duty-cycle as amplitude of input signal increased. But we confirmed that after 10 cycles passed, duty-cycles was staying below 52% of duty-cycle for any magnitude of input signal.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.982-988
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• 2002

This paper summarizes the design concepts and implementation of a Ku-band channel amplifier's engineering model for the communication and broadcasting satellite applications. The selected architecture uses the analog gain control for the FGM(Fixed Gain Mode) and the output level limiting using automatic loop control for the ALC (automatic level control) mode. The Ku-band channel amplifier incorporates several state-of-the-art components including voltage-controlled PIN diode attenuators, and various temperature-compensation circuits. The measured characteristics of the Ku-band channel amplifier are in good agreement with the expected performance. The results show a fixed gain control of 28 dB, and an automatic level control of 16 dB over operating temperature range. The designed engineering model could be used as a channel amplifier for Ku-band communication and broadcasting satellite payload system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.119-124
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• 2008

Transimpedance amplifier(TIA) is the most significant element to determine the performance of the optical receiver, and thus the TIA must satisfy tile design requirements of high gain and wide bandwidth. In f)is paper, we propose a novel single chip optical receiver that exploits an analog adaptive equalizer and a limiting amplifier to enhance the gain and bandwidth performance, respectively. The proposed optical receiver is designed by using a $0.13{\mu}m$ CMOS process and its post-layout simulations show $120dB{\Omgea}$ transimpedance gain and 5.88GHz bandwidth. The chip core occupies the area of $0.088mm^2$, due to utilizing the negative impedance converter circuit rather than using on-chip passive inductors.