• Title/Summary/Keyword: broad-band

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Compact Broad Band-pass Filter with SIR-Parallel Coupled Structure (SIR 평행결합 선로를 갖는 소형 광대역 대역통과 필터)

  • Hong, Tae-Ui;Lee, Jeong-Hun;Yoon, Ki-Cheol
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.11
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    • pp.84-90
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    • 2010
  • In this paper, the reduced size of broad bandpass filter with parallel coupled line structure is presented. This proposed filter can control bandwidth of narrow to broadband by adjusting the coupling coefficient. The conventional filter is operated with a narrow band. If a higher bandwidth is desired than the conventional narrow bandwidth, it is hard to realize due to the coupling coefficient between feeding line and resonator. In this paper, to overcome this limitation, a proposed bandpass filter is designed with reduced size due to SIR(Stepped Impedance Resonator) and multi-grade type structures than conventional one, and it has characteristics of adjusting bandwidth freely as per quantity of coupling coefficient. The proposed bandpass filter that, experimental results of insertion and return losses are 0.42 dB and 20.9 dB with bandwidth of 60 % at the center frequency of 5.8 GHz, respectively.

A Broad-Band Metamaterial Absorber Using Flexible Substrate (유연성 기판을 사용한 광대역 메타 흡수체)

  • Lee, Hong-Min
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.3
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    • pp.339-347
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    • 2014
  • In this paper, the authors present a new design for a broad-band metamaterial(MTM) absorber that utilizes flexible substrate. The proposed MTM unit cell is constructed by a electric-inducive-capacitive(ELC) resonator and a cut-wire on the same side of the flexible polyimide substrate. To reduce the radar cross section at frequencies other than the targeted frequency bands, the metallic pattern layer of the proposed structure is placed facing toward the incident wave propagation direction. A prototype absorber was fabricated with a planar array of $33{\times}45$ unit cells. Our experiments showed that the proposed absorber exhibits a peak absorption rate of 92 % and 93 % at 9.06 GHz and 15.0 GHz, respectively, and 75 % of the full-width at half-maximum(FWHM) bandwidth is achieved. The proposed backplane-less MTM structure can be used for a broad-band microwave absorber and irregular surface applications.

High frequency P velocity and attenuation coefficient of the rocks under the broad-band seismic station (광대역 관측소 하부 암석의 고주파수 탄성파 속도 및 감쇠상수에 대한 연구)

  • Lee, Duk-Kee;Oh, Seok-Hoon;Youn, Yong-Hoon;Yang, Jun-Mo
    • Journal of the Korean Geophysical Society
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    • v.5 no.3
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    • pp.165-174
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    • 2002
  • Seismic velocity and attenuation coefficient of the rocks under the broad-band earthquake observatories of the Korea Meteorological Administration have been measured in the laboratory by using very high frequency seismic waves. Estimated P velocities of the rocks range from 3.2 km/s to 5.6 km/s, depending on the rock type, mineral, and weathering, while, the attenuation coefficients vary from 0.06 to 4.3 db/kHz-m. It seems that P velocities is inversely proportional to the attenuation coefficients of the rocks. Average travel-time delays of the broad-band stations seem to be related with the measured P velocities in the laboratory.

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Trans Korean Peninsula-Japanese Island Seismic Observation and Analysis; Seismic Observation of Broad Band and Wide Dynamic Range at Pohang STS Observatory, Korea (한반도-일본열도 사이의 광역지진관측 및 해석 ; 포항 STS지진관측소에서의 광대역, 고감도의 지진관측)

  • Kim, Sung Kyun;Chung, Seung Hwan;Jun, Myung Soon;Kyung, Jai Bok;Jeon, Jeong Soo;Ryoo, Yong Gyu;Oike, Kazuo;Fukao, Yoshio;Yamada, Isao;Ishihara, Keiko;Ishihara, Yasushi
    • Economic and Environmental Geology
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    • v.26 no.1
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    • pp.97-106
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    • 1993
  • In order to provide informations for the earth's deep interior and the earthquake mechanism, we have been operating the three components of Streckeisen Seismometers at Pohang Observatory, Korea, as a part of a long period seismic network (POSEIDON) in the northwestern Pacific now under construction. The recording system is specially designed to be able to obtain outputs of broad band and wide dynamic range; BRB (Broad Band), LP (Long Period), and VLP (Very Long Period) output. The triggered BRB and LP signals are digitized with the sampling intervals of 0.1 and 0.4 second, respectively. The lowpass filtered VLP output is digitized and recorded contineously with the sampling interval of 10 seconds. About 120 regional and teleseismic events have been successfully recorded for one and half year since late March, 1991. As a preliminary study, eight events of them are analyzed to determine Rayleigh wave dispersion curves in the period range of 20 to 300 seconds for the continental and oceanic paths. The curves are compared with the typical continental and oceanic ones to discuss the earth's deep interior.

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Compact Broad Band-pass Filter of Parallel Coupled Structure with SIR (SIR을 이용한 평행결합 선로의 소형 광대역 대역통과 필터)

  • Lee, Jeong-Hun;Hong, Tae-Ui;Yoon, Ki-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.4A
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    • pp.407-413
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    • 2011
  • In this paper, the reduced size of broad bandpass filter with parallel coupled line structure is presented. This proposed filter can control bandwidth of narrow to broadband by adjusting the coupling coefficient. The conventional filter is operated with a narrow band. If a higher bandwidth is desired than the conventional narrow bandwidth, it is hard to realize due to the coupling coefficient between feeding line and resonator. In this paper, to overcome this limitation, a proposed bandpass filter is designed with reduced size due to SIR (Stepped Impedance Resonator), U-shaped open stub with hair-pin and vertical-type structure than conventional one, and it has characteristics of adjusting bandwidth freely as per quantity of coupling coefficient. The proposed bandpass filter that, experimental results of insertion and return losses are 0.42 dB and 24.5 dB with bandwidth of 60 % at the center frequency of 5.8 GHz, respectively.

Derivation and Comparison of Narrow and Broadband Algorithms for the Retrieval of Ocean Color Information from Multi-Spectral Camera on Kompsat-2 Satellite

  • Ahn, Yu-Hwan;Shanmugam, Palanisamy;Ryu, Joo-Hyung;Moon, Jeong-Eom
    • Korean Journal of Remote Sensing
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    • v.21 no.3
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    • pp.173-188
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    • 2005
  • The present study aims to derive and compare narrow and broad bandwidths of ocean color sensor’s algorithms for the study of monitoring highly dynamic coastal oceanic environmental parameters using high-resolution imagery acquired from Multi-spectral Camera (MSC) on KOMPSAT-2. These algorithms are derived based on a large data set of remote sensing reflectances ($R_{rs}$) generated by using numerical model that relates $b_b/(a + b_b)$ to $R_{rs}$ as functions of inherent optical properties, such as absorption and backscattering coefficients of six water components including water, phytoplankton (chl), dissolved organic matter (DOM), suspended sediment (SS) concentration, heterotropic organism (he) and an unknown component, possibly represented by bubbles or other particulates unrelated to the first five components. The modeled $R_{rs}$ spectra appear to be consistent with in-situ spectra collected from Korean waters. As Kompsat-2 MSC has similar spectral characteristics with Landsat-5 Thematic Mapper (TM), the model generated $R_{rs}$ values at 2 ㎚ interval are converted to the equivalent remote sensing reflectances at MSC and TM bands. The empirical relationships between the spectral ratios of modeled $R_{rs}$ and chlorophyll concentrations are established in order to derive algorithms for both TM and MSC. Similarly, algorithms are obtained by relating a single band reflectance (band 2) to the suspended sediment concentrations. These algorithms derived by taking into account the narrow and broad spectral bandwidths are compared and assessed. Findings suggest that there was less difference between the broad and narrow band relationships, and the determination coefficient $(r^2)$ for log-transformed data [ N = 500] was interestingly found to be $(r^2)$ = 0.90 for both TM and MSC. Similarly, the determination coefficient for log-transformed data [ N = 500] was 0.93 and 0.92 for TM and MSC respectively. The algorithms presented here are expected to make significant contribution to the enhanced understanding of coastal oceanic environmental parameters using Multi-spectral Camera.

A Study on the Ray Based Broad Band Modeling for Shallow Water Acoustic Wave Propagations (천해 음파전달 모의에 적합한 음선기반 광대역 신호 모델링 기법에 관한 연구)

  • Park Cheol-Soo;Cho Yong-Jin;Ahn Jong-Woo;Seong Woo-Jae
    • The Journal of the Acoustical Society of Korea
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    • v.25 no.6
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    • pp.298-304
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    • 2006
  • This paper proposes a ray-based forward modeling scheme which is suitable for the shallow water acoustic wave propagation simulations. The proposed model comprises of ray tracings for the layered media of which sound speed profiles are interpolated linearly. considerations of plane and spherical wave reflection coefficients. and calculations of the phases and the amplitudes of eigen rays. The main characteristic of the scheme is fast simulation time due to direct calculation of the broad-band time signals in the time-domain, i.e. without transformation of the frequency-domain solutions to the time si 밍 131s. Finally, we applied the model to 4-types of test environments and compared the resulting signals with those of ORCA and Ram in order to validate the proposed model.

A Study on the Classification of Forest by Landsat TM Data (Landsat TM 자료를 이용한 임종구분에 관한 연구)

  • 최승필;홍성태;박재훈
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.11 no.1
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    • pp.55-60
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    • 1993
  • Forest occupied a part of natural ecosystem carries out a role of purifying air, preserving water resource, prevention of the breeding and extermination, recreation areas and etc that preserve and for me one's living environment. In this study, the classification for management of this forest is performed with Landsat TM Image. The classes are decided needle-leaf trees, broad-leaf trees, farming land and grass land, and water. When the TM digital images are classified on computer, water is represented in 7∼13 D.N. of 4th band. But the others is appeared similar mostly specific values so that must be done image processing. When the images compounded 2ed band and 3ed band are processed with ratio of enhancement. Needle-leaf treas is represented in l18∼136 D.N. of 1st band, broad-leaf trees in 72∼91 D.N. of 3ed band, farm land and glass land in 96∼120 of 3ed band. Forest Information is classified with M.L.C, an image classification method. The errors of needle-leaf trees, broad-leaf trees, farm land and grass land, and water are appeared each -7.43, +1.89,+7.58 and -2.04 as compared the digital image with investigation on the scene. Finally, these results are useful for classification of forest vegetation with Landsat TM Image.

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The Study of G- Banding Chromosome in Silkie (오골계의 염색체 분염법 (G-banding)에 따른 핵형분석에 관한 연구)

  • 강태석;오봉국;손시환
    • Korean Journal of Poultry Science
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    • v.12 no.2
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    • pp.83-87
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    • 1985
  • This experiment was carried out to identify the chromosomes of silkie. It was many difference from other breeds in morphology and characteristics. In this experiment, chromosomal analysis was used early embryos. In aspect of morphological chromosomes, chromosomal size and shape are similar to other breeds. The chromosomes of silkie were shown to morphlogy as follows. They were identified that chromosome #l and #2 were grouped as submentacentric, #3, #5 and #6 were telocentric #4 and #7 were acrocentric and #8 was metacentric chromosome. Zㆍsex chromosome was shown 5th, W-sex chromosome was 8th to 9th and they were metacentric chromosome, respectively. Each chromosome through the G-banding was shown the 3 dark bands in 1 p2, distinct light band in 1p1, dark band in 2p2, broad light band in 3pl, dark band from centromere and distal part in 4th chromosome and dark band in 5pl. Z-sex chromosome was shown dark at p-arm distal part.

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A Compact C-Band Semi-Lumped Lowpass Filter with Broad Stopband Using a Chip Inductor (칩 인덕터를 사용하여 광대역 저지 특성을 갖는 소형 C-밴드 Semi-Lumped 저역 통과 여파기)

  • Jang, Ki-Eon;Lee, Gi-Moon;Kim, Ha-Chul;Choi, Hyun-Chul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.12
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    • pp.1359-1364
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    • 2012
  • The C-band semi-lumped lowpass filter with broad stopband and compact size characteristic using chip inductor is proposed. To provide an additional attenuation pole in stopband by SRF, a separable inductor is added to proposed structure, and it has broad stopband characteristic. The third order elliptic function lowpass filter with chip inductor(L: 9.1 nH, SRF: 5.5 GHz, Q: 25) has insertion loss of 0.38 dB, cutoff frequency of 920 MHz, broad stopband(below 20 dB) of 1.43~7.8 GHz and the size is reduced 37.4 % compared to distributed inductor.