• Journal of the Microelectronics and Packaging Society
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• v.15 no.1
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• pp.19-25
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• 2008

In this paper, the front end module (FEM) was proposed for 2.4GHz WLAN band by LTCC multilayer application. The FEM was composed of power amplifier IC, switch IC, and LTCC module. LTCC module consists of output matching circuit and lowpass filter as Tx part, bandpass filter as Rx part. Design of output matching circuit for LTCC was used matching parameter from output matching circuit based on lumped circuit on the PCB board. The dielectric constant of LTCC substrate is 9. The substrate was composed of total 26 layers with each 30um thickness. Ag paste was used for the internal pattern as the conductor material. The size of the module is $4.5mm{\times}3.2mm{\times}1.4mm$. The fabricated FEM showed the gain of 21dB, ACPR of less than -31dBc first side lobe and Less than -59dBc second side lobe and the output power of 23Bm at P1dB.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.1
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• pp.60-68
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• 2010

In case of sensorineural hearing loss, auditory perception can be activated by electrical stimulation of the nervous system via electrode implanted into the cochlea or auditory nerve. Since the tonotopic map of the human auditory nerve has not been definitively identified, the recording of auditory nerve signal with microelectrode is desirable for determining the tonotopic map. This paper proposes the multi-channel analog front-end for auditory nerve signal detection. A channel of the proposed analog front-end consists of an AC coupling circuit, a low-power 4th-order Gm-C LPF, and a single-slope ADC. The AC coupling circuit transfers only AC signal while it blocks DC signal level. Considering the bandwidth of the auditory signal, the Gm-C LPF is designed with OTAs adopting floating-gate technique. For the channel-parallel ADC structure, the single-slope ADC is used because it occupies the small silicon area. Experimental results shows that the AC coupling circuit and LPF have the bandwidth of 100 Hz - 6.95 kHz and the ADC has the effective resolution of 7.7 bits. The power consumption per a channel is $12\;{\mu}W$, the power supply is 3.0 V, and the core area is $2.6\;mm\;{\times}\;3.7\;mm$. The proposed analog front-end was fabricated in a 1-poly 4-metal $0.35-{\mu}m$ CMOS process.

• Journal of IKEEE
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• v.14 no.1
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• pp.8-16
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• 2010

This paper presents a design of the successive approximation ADC(SA-ADC) applicable to a midium-low speed analog-front end(AFE) for the maximum 15MS/s CCD image processing. SA-ADC is effective in applications ranging widely between low and mid data rates due to the large power scaling effect on the operating frequency variations in some other way of pipelined ADCs. The proposed design exhibits some distinctive features. The "differential capacitor-coupling scheme" segregates the input sampling behavior from the sub-DAC incorporating the differential input and the sub-DAC output, which prominently reduces the loading throughout the signal path. Determining the MSB(sign bit) from the held input data in advance of the data conversion period, a kind of the signed successive approximation, leads to the reduction of the sub-DAC hardware overhead by 1 bit and the conversion period by 1 cycle. Characterizing the proposed design in a 3.3 V $0.35-{\mu}m$ CMOS process by Spectre simulations verified its validity of the application to CCD analog front-ends.

• Proceedings of the Korea Database Society Conference
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• 2001.06a
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• pp.213-234
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• 2001

1. Brokat Server Technologies (Channel 통합 Messging Server) 복잡한 메시지 교환을 유연하게 제어함으로써 Front-End/Back-End각각에 존재하는 다양한 채널을 RealTime으로, 유연하게 통합관리하여 채널간의 Messaging을 Smart하게 컨트롤 2. Brokat Advisor (Rulebase Management System) 복잡한 비즈니스 룰의 적용과 Non-Programming/다이나믹한 관리를 동시에 가능하게 하는 Large E Business Engine (중략)

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.136.2-136.2
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• 2008

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.189-196
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• 2003

In this study, the vertical opening of the non-float midwater pair trawl net was maintained by controlling the length of upper warp. This was because the head rope was able to be kept linearly and the working depth was not nearly as changed with the variation of flow speed as former experiments in this series of studies have demonstrated. We confirmed that the opening efficiency of the non-float midwater pair trawl net was able to be developed according to the increase in front weight and wing-end weight. In this study, we described the opening efficiency of the non-float midwater pair trawl net according to the variation of front weight and wing-end weight obtained by model experiment in circulation water channel. We compared the opening efficiency of the proto type with that of the non-float type. The results obtained can be summarized as follows：1. The hydrodynamic resistance was almost increased linearly in proportion to the flow speed and was increased in accordance with the increase in front weight and wing-end weight. The increasing rate of hydrodynamic resistance was displayed as an increasing tendency in accordance with the increase in flow speed. 2. The net height of the non-float type was almost decreased linearly in accordance with the increase in flow speed. As the reduced rate of the net height of the non-float type was smaller than that of the net height of the proto type against increase of flow speed, the net height of the non-float type was bigger than that of the proto type over 4.0 knot. The net width of the non-float type was about 10 m bigger than that of the proto type and the change rate of net width varied by no more than 2 m according to the variation of the front weight and wing-end weight. 3. The mouth area of the non-float type was maximized at 1.75 ton of the front weight and 1.11 ton of the wing-end weight, and was smaller than that of the proto type at 2.0∼3.0 knot, but was bigger than that of the proto type at 4.0∼5.0 knot. 4. The filtering volume was maximized at 3.0 knot in the proto type and at 4.0 knot in the non-float type. The optimal front weight was 1.40 ton.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.6
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• pp.190-194
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• 2006

This research investigates vehicle structure acceleration and vehicle deformation with RCAR crash test. To investigate vehicle damage characteristics in an individual case, it is possible to RCAR low speed crash test. In this study, two tests were conducted to evaluate difference between RCAR new condition and RCAR old condition. A two large vehicles were subjected to a frontal crash test at a speed of 15km/h with an offset of 40% $10^{\circ}$ angle barrier and flat barrier. The results of the 15km/h with an offset of 40% $10^{\circ}$ angle barrier revealed high acceleration value on the vehicle structure and high repair cost compared to the RCAR 15km/h with an offset of 40% flat barrier. So in order to improve damage characteristics in low speed crash of vehicle structure and body component of the monocoque type passenger vehicles, the end of front side member and front back beam should be designed with optimum level and to supply the end of front side member as a partial condition approx 300mm.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.13-19
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• 2012

The fatalities rate for passenger vehicles, vans, and commercial vehicles is 1.23, 1.90 and 2.46 deaths per 10,000 registered vehicles, respectively. This shows that vans and commercial vehicles are vulnerable compare to passenger vehicles. To evaluate the crashworthiness of van and Light Truck Vehicle(LTV), we carried out frontal offset crash test at 64km/h, 40% overlap as per IIHS(Insurance Institute for Highway Safety). The test result show that LTV is very poor to protect occupant at frontal crash cause there is no safety system such as airbag and pretensioner and front end length(distance from front bumper to steering wheel) is short. One of the van rated as the lowest rating even it is equipped with airbag, cause its safety cage was collapsed during the test. This result shows that the structural integrity is very important in terms of occupant protection.

• ETRI Journal
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• v.26 no.6
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• pp.555-559
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• 2004

We propose an efficient digital IF down converter architecture for dual-mode WCDMA/cdma2000 based on the concept of software defined radio. Multi-rate digital filters and fractional frequency conversion techniques are adopted to implement the front end of a dual-mode receiver for WCDMA and cdma2000. A sub-sampled digital IF stage was proposed to support both WCDMA and cdma2000 while lowering the sampling frequency. Use of a CIC filter and ISOP filter combined with proper arrangement of multi-rate filters and common filter blocks resulted in optimized hardware implementation of the front end block in 292k logic gates.

• ETRI Journal
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• v.27 no.5
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• pp.484-490
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• 2005

We fabricated 40 Gb/s front-end optical receivers using spot-size converter integrated waveguide photodiodes (SSC-WGPDs). The fabricated SSC-WGPD chips showed a high responsivity of approximately 0.8 A/W and a 3 dB bandwidth of approximately 40 GHz. A selective wet-etching method was first adopted to realize the required width and depth of a tapered waveguide. Two types of electrical pre-amplifier chips were used in our study. One has higher gain and the other has a broader bandwidth. The 3 dB bandwidths of the higher gain and broader bandwidth modules were about 32 and 42 GHz, respectively. Clear 40 Gb/s non-return-to-zero (NRZ) eye diagrams showed good system applicability of these modules.