• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.341-342
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• 2007

The IRFPA (InfraRed Focal Plane Array) ROIC (ReadOut Integrated Circuit) was designed in folded-cascode Op-Amp using $0.35{\mu}m$ CMOS technology. As the folded-cascode has high open-loop voltage gain and fast settling time, that used in many analog circuit designs. In this paper, folded-cascode Op-Amp for ROIC of the $32{\times}32$ IRFPA has been designed. HSPICE simulation results are unit gain bandwidth of 13.0MHz, 90.6 dB open loop gain, 8 V/${\mu}m$ slew rate, 600 ns settling time and $66^{\circ}$ phase margin.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.2
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• pp.152-159
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• 2007

This paper describes the design, fabrication, and measurement of ROIC(ReadOut Integrated Circuit) for $320{\times}256$ IRFPA(InfraRed Focal Plane Array). A ROIC plays an important role that transfer photocurrent generated in a detector device to thermal image system. Recently, the high performance and low power ROIC adding various functions is being required. According to this requirement, the design of ROIC focuses on 7MHz or more pixel rate, low power dissipation, anti-blooming, multi-channel output mode, image reversal, various windowing, and frame CDS(Correlated Double Sampling). The designed ROIC was fabricated using $0.6{\mu}m$ double-poly triple-metal Si CMOS process. ROIC function factors work normally, and the power dissipation of ROIC is 33mW and 90.5mW at 7.5MHz pixel rate in the 1-channel and 4-channel operation, respectively.

• Aerospace Engineering and Technology
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• v.11 no.1
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• pp.98-102
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• 2012

These days, Uncooled IR Systems are more popular in the area of defense and aerospace than before. Uncooled IR Systems are widely used as core technology for making unmanned systems and detecting enemy objects during the day and night in the distance. Recently, researches on TEC-less IRFPA have been increased to minimize the power consumption and to make a smaller system than before. For this, it needs to find adequate NUC(Non-Uniformity Correction) coefficients as FPA(Focal Plane Array) temperature changes. In this paper, we propose a new NUC coefficient estimating technique, DCCE-LI(Dynamic Calibration Coefficients Estimation with Linear Interpolation), for TEC-less IRFPA. It is based on a linear interpolation method and it can estimate NUC coefficients in real-time. So, by testing and evaluating it with some IR images, we conclude that the quality of IR images using proposed method is better than applying static coefficients.

• Journal of the Optical Society of Korea
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• v.17 no.2
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• pp.213-218
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• 2013

Although infrared focal plane array (IRFPA) detectors have been commonly used, non-uniformity correction (NUC) remains an important problem in the infrared imaging realm. Non-uniformity severely degrades image quality and affects radiometric accuracy in infrared imaging applications. Residual non-uniformity (RNU) significantly affects the detection range of infrared surveillance and reconnaissance systems. More effort should be exerted to improve IRFPA uniformity. A novel NUC method that considers the surrounding temperature variation compensation is proposed based on the binary nonlinear non-uniformity theory model. The implementing procedure is described in detail. This approach simultaneously corrects response nonlinearity and compensates for the influence of surrounding temperature shift. Both qualitative evaluation and quantitative test comparison are performed among several correction technologies. The experimental result shows that the residual non-uniformity, which is corrected by the proposed method, is steady at approximately 0.02 percentage points within the target temperature range of 283 K to 373 K. Real-time imaging shows that the proposed method improves image quality better than traditional techniques.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.5
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• pp.27-37
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• 1999

A CMOS ReadOut Integrated Circuit (ROlC) for InfraRed Focal Plane Array (IRFPA) detector is presented, which is a key component in uncooled thermal imaging systems. The ROIC reads out signals from $64\times64$ Barium Strontium Titanate (BST) infrared detector array, then outputs pixel signals sequentially after amplifying and noise filtering. Various design requirements and constraints have been considered including impedance matching, low noise, low power dissipation and small detector pitch. For impedance matching between detector and pre~amplifier, a new circuit based on MOS diode structure is devised, which can be easily implemented using standard CMOS process. Also, tunable low pass filter with single~pole is used to suppress high frequency noise. In additions, a clamping circuit is adopted to enhance the signal~to-noise ratio of the readout output signals. The $64\times64$ IRFPA ROIC is designed using $0.65-\mu\textrm{m}$ 2P3M (double poly, tripple metal) N~Well CMOS process. The core part of the chip contains 62,000 devices including transistors, capacitors and resistors on an area of about $6.3-mm\times6.7-mm$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.11
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• pp.7-13
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• 2002

BSCT 320${\times}$240 IRFPA detector module is implemented, which is a key component in uncooled thermal imaging systems. The detector module consists of two parts, infrared sensitive pixel array and read-out integrated circuit(ROIC). The BSCT 320${\times}$240 pixels are made by laser scribe process and 10-${\mu}m$ micro-bump to satisfy 50-${\mu}m$ pitch and 95-% fill-factor. The ROIC has been designed to electrically address the pixels sequentailly and to improve signal-to-noise ratio with single transistor amplifier, HPF, tunable LPF and clamp circuit. The fabricated hybrid chip of detector and ROIC has been mounted on the TEC built-in ceramic package for more stable operation and tested for lots of electrical and optical properties. The IRFA sample has shown successful properties and met with good results of fill-factor, detectivity and responsivity.

• Journal of the Korean Physical Society
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• v.73 no.12
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• pp.1821-1826
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• 2018

Uniformity is a key feature of state-of-the-art infrared focal planed array (IRFPA) and infrared imaging system. Unlike traditional infrared telescope facility, a ground-based infrared radiant characteristics measurement system with an IRFPA not only provides a series of high signal-to-noise ratio (SNR) infrared image but also ensures the validity of radiant measurement data. Normally, a long integration time tends to produce a high SNR infrared image for infrared radiant characteristics radiometry system. In view of the variability of and uncertainty in the measured target's energy, the operation of switching the integration time and attenuators usually guarantees the guality of the infrared radiation measurement data obtainted during the infrared radiant characteristics radiometry process. Non-uniformity correction (NUC) coefficients in a given integration time are often applied to a specified integration time. If the integration time is switched, the SNR for the infrared imaging will degenerate rapidly. Considering the effect of the SNR for the infrared image and the infrared radiant characteristics radiometry above, we propose a-wide-dynamic-range NUC algorithm. In addition, this essasy derives and establishes the mathematical modal of the algorithm in detail. Then, we conduct verification experiments by using a ground-based MWIR(Mid-wave Infared) radiant characteristics radiometry system with an Ø400 mm aperture. The experimental results obtained using the proposed algorithm and the traditional algorithm for different integration time are compared. The statistical data shows that the average non-uniformity for the proposed algorithm decreased from 0.77% to 0.21% at 2.5 ms and from 1.33% to 0.26% at 5.5 ms. The testing results demonstrate that the usage of suggested algorithm can improve infrared imaging quality and radiation measurement accuracy.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.4
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• pp.94-101
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• 2009

In this paper, we propose design of hardware based on a high speed digital signal processor (DSP) and a field programmable gate array (FPGA) for real-time suppression of fixed pattern noise (FPN) using hardware neural networks (HNN) in cooled infrared focal plane array (IRFPA) imaging system FPN appears a limited operation by temperature in observable images which applies to non-uniformity correction for infrared detector. These have very important problems because it happen serious problem for other applications as well as degradation for image quality in our system Signal processing architecture for our system operates reference gain and offset values using three tables for low, normal, and high temperatures. Proposed method creates virtual tables to separate for overlapping region in three offset tables. We also choose an optimum tenn of temperature which controls weighted values of HNN using mean values of pixels in three regions. This operates gain and offset tables for low, normal, and high temperatures from mean values of pixels and it recursively don't have to do an offset compensation in operation of our system Based on experimental results, proposed method showed improved quality of image which suppressed FPN by change of temperature distribution from an observational image in real-time system.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2600-2602
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• 2004

열상장비는 물체가 방출하는 적외선 영역의 미약한 에너지를 검출하여 눈에 보이는 영상으로 변환하는 장비이다. 주간과 동일한 영상을 야간에도 획득할 수 있기 때문에 야간 감시등 군사용 장비로 활용되지만 최근에는 송전선로의 이상 유무 판단, 저장 탱크의 저장량 확인, 사스 환자의 체열 검색 등 산업계와 의료계의 이용도 증가하고 있다. 본 논문에서는 최신 기술인 주사방식 초점면 배열 열상장비의 아날로그 및 디지털신호처리기 설계와 제작 기술을 다룬다. $480{\times}6$ 배열의 고밀도 검출 소자를 이용하여 고속, 저잡음 신호처리를 함으로써 안정된 열 영상을 실시간으로 획득하였다.

• Journal of Sensor Science and Technology
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• v.18 no.4
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• pp.301-306
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• 2009

This paper describes the design and fabrication of 16$\times$16 microbolometer infrared focal plane arrays based on iMEMS technology. Amorphous silicon was used for infrared-sensitive material, and it showed the resistance of 18 Mohm and the temperature coefficient of resistivity of -2.4 %. The fabricated sensors exhibited responsivity of 78 kV/W and thermal time constant of 8.0 msec at a bias voltage of 0.5 V. The array performances had satisfactory uniformity less than 5 % within one-sigma. Also, 1/f noise of pixel was measured and the noise factor of $6\times10^{-11}$ was extracted. Finally, we obtained detectivity of $1.27\times10^9cmHz^{0.5}/W$ and noise equivalent temperature difference of 200 mK at a frame rate of 30 Hz.