• Proceedings of the KIEE Conference
• /
• 2003.11b
• /
• pp.75-78
• /
• 2003

In this paper, a second-order 3-bit DSM using DWA(Data Weighted Averaging) algorithm is designed for bluetooth Zero-IF Receiver. The designed circuit has two integrators using a designed OTA, nonoverlapping two-phase clerk generator, 3-bit A/D converter, DWA algorithm and 3-bit D/A converter An ideal model of second-order lowpass DSM with a 3-bit quantizer was configured by using MATLAB, and each coefficients and design specification of each blocks were determined to have 10-bit resolution in 1MHz channel bandwidth. The designed second-order 3-blt lowpass DSM has maximum SNR of 74dB and power consumption is 50mW at 3.3V.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.54-56
• /
• 2009

We propose an image change detection algorithm implemented on sensor nodes of the ubiquitous sensor network(USN). The proposed algorithm was designed for the robust detection of image changes regardless of the continuously changing ambient illumination environment. Morphological lowpass filter was used for estimating the illumination component in order to reduce computational burden instead of the existing Gaussian lowpass filter. The decision of the change detection is based on the result of threshold of difference image between two consecutive images. We also propose a new thresholding method using precalculated histogram information. The proposed algorithm was implemented on the MSP430 16bit microprocessor.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2003.11a
• /
• pp.352-356
• /
• 2003

본 논문에서는 매우 넓은 저지대역과 우수한 cutoff 특성을 갖는 저역통과 여파기를 제안하였다. 접지면 슬롯과 급전면 개방 스터브의 특성을 결합한 기존의 광대역 여파기에서 전송선의 길이를 ${\lambda}_g/4$로 변형함으로써 기존의 여파기보다 더 작은 크기로 넓은 저지대역과 급격한 cutoff 특성을 얻을 수 있었다. 또한 설계한 단위 여파기를 특정 간격로 배열하여 더 깊은 저지대역과 향상된 cutoff 특성을 얻을 수 있었다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2003.11a
• /
• pp.338-342
• /
• 2003

본 논문에서는 개방 스터브(open stub)와 전송선로가 커플된(coupled) 구조를 Chebyshev prototype을 이용하여 저역통과 여파기를 설계하였다. 같은 길이의 스터브를 연속적으로 배열함으로써 깊은 저지대역을 갖고, 커플링에 의해 우수한 스컷 (skirt) 특성을 갖는 여파기를 설계할 수 있었다. 또한, 감쇄극이 다른 스터브를 추가로 연결하여 저지대역을 확장하였다.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.7
• /
• pp.1254-1259
• /
• 2008

A new CMOS current-mode integrator for low-voltage analog integrated circuit design is presented. The proposed current-mode integrator is based on cross-coupled gain-boosting topology. When it is compared with that of the typical current-mirror type current-mode integrator, the proposed current-mode integrator achieves high current gain and unity gain frequency with the same transistor size. As a application circuit of the proposed integrator, we designed the 1.8V 200MHz band current-mode lowpass filter. These are verified by Hspice simulation using $0.18{\mu}m$ CMOS technology.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.543-543
• /
• 2000

A new method for HRV(heart rate variability) detection from the R-wave signal, based on the IPFM(integral pulse frequency modulation) model and its similarity to pulse position modulation, is presented. The proposed method exert lowpass filtering with a Kaiser window. In this paper, The proposed method presents a powerful, but simple, tool for investigation of HRV. It also guarantees real-time behavior. simplicity in design, and phase linearity. Even without the basic assumption of IPFM model. the new algorithm can still be used on-line and with higher performance. It is thoroughly proved that lowpass filtering is an ideal method for PSD(Power Spectrum Density) analysis of HRV.

• Proceedings of the IEEK Conference
• /
• summer
• /
• pp.19-22
• /
• 2004

The goal of this study is to realize the PBG lowpass filter using novel PBG structure modification both upper layer and ground layer. It has been designed three aperture slots of ground layer for PBG structure which the center slot shape of ground is two type, rectangular and dumbbell. This PBG LPF has the character of the broader stopband and smaller size than typical LPF. The measurement results have matched the simulated ones. It has the cutoff frequency of each 4.465GHz and 3.52GHz and at least -20dB of the signal suppression at the stopband

• Journal of electromagnetic engineering and science
• /
• v.11 no.4
• /
• pp.257-261
• /
• 2011

A highly efficient 2.4 GHz rectenna is designed using a harmonic rejection bandpass filter. The rectenna is printed on Rogers Duroid 5880 substrate with ${\varepsilon}_r$=2.2 and a thickness of 1.6 mm. The rectenna consists of a microstrip antenna and high order harmonic rejection bandpass filter, microstrip lowpass filter, and Schottky barrier diode (HSMS2820). The use of a $2^{nd}$ and $3^{rd}$ harmonic rejection microstrip bandpass filter in the rectenna results in high conversion efficiency. The proposed rectenna achieves a RF to DC conversion efficiency of 72.17 % when the received RF power is 63.09 mW.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.46-49
• /
• 2000

An iterative deblocking algorithm for DCT-compressed images using two-dimensional FIR filters adapted for local directionality of each block, is proposed. First, we introduce a set of simple lowpass filters, which are adapted for edges of different angles. In conventional deblocking methods based on lowpass-filtering and convex projections, a single filter is applied to a whole image. In the proposed method, on the other hand, a suitable filter is chosen out of the directional filters designed previously in every subimage (typically $8{\times}8$ block). Experimental results indicate that adaptive filtering improves PSNR at each iteration.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.53 no.8
• /
• pp.611-614
• /
• 2004

In this paper, we propose an adaptive blocking artifact reduction algorithm using characteristics of the block boundaries. Blocking artifacts contain the high frequency components near the block boundaries, so the lowpass filtering can remove them. But a simple lowpass filtering results into blurring by remove important features such as edges. To overcome this problem, we determine the modes depending on the characteristics around boundaries then proper filter is applied to each area. Simulation results show that the proposed method improves deblocking performance compared to that of MPEG-4.