• Title/Summary/Keyword: High frequency band

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Study Of Millimeter-Wave Passive Imaging Sensor Using the Horn Array Antenna (혼 배열 안테나를 이용한 밀리미터파 수동 이미징 센서 연구)

  • Lim, Hyun-Jun;Chae, Yeon-Sik;Kim, Mi-Ra;Rhee, Jin-Koo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.2
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    • pp.74-79
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    • 2010
  • We have designed a millimeter-wave passive imaging sensor with multi-horn antenna array. Six horn array antenna is suggested that it is integrated into one housing, and this antenna is effectively configurated m space to assemble with LNA of WR-10 structure. Antenna is designed to have the peak gain of 17.5dBi at the center frequency of 94GHz, and the return loss of less than -25dB in W-band, and the small aperture size of $6mm{\times}9mm$ for antenna configuration with high resolution. LNA is designed to have total gain of more than 55dB and noise figure of less than 5dB for good sensitivity. We made a detector for DC output translation of millimeter-wave signal with zero bias Schottky diode. It is shown that good sensitivity of more than 500mV/mW.

A SiGe HBT of Current Gain Modulation By using Passivation Ledge (Passivation Ledge를 이용한 SiGe HBT의 Current Gain Modulation)

  • You, Byoung-Sung;Cho, Hee-Yup;Ku, Youn-Seo;Ahn, Chul
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.771-774
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    • 2003
  • Passivation Ledge's device is taken possession on one-side to the Emitter in this Paper. contact used in this paper Pt as Passivation Ledge of device to use Schottky Diode which has leitmotif, It is accomplished Current Modulation that we wish to do purpose using this device. Space Charge acts as single device which is becoming Passivation to know this phenomenon. This device becomes floating as well as Punched-through. V$_{L}$ (Voltage for Ledge) = - 0.5V ~ 0.5V variable values , PD(Partially Depleted ; Λ>0), as seeing FD(Fully Depleted ; A = 0) maximum electric current gains and Gummel Plot of I-V characteristics (V$_{L}$ = 0.1/ V$_{L}$ = -0.1 ). Becomming Degradation under more than V$_{L}$ = 0.1 , less than V$_{L}$ =-0.05 and Maximum Gain(=98.617076 A/A) value in the condition V$_{L}$ = 0.1. A Change of Modulation is electric current gains by using Schottky Diode and Extrinsic Base PN Diode of Passivation Ledge to Emitter Depletion Layer in HBT of Gummel-Poon I-V characteristics and the RF wide-band electric current gains change the Modulation of CE(Common-Emitter) amplifier description, and it had accomplished Current Gain Modulation by Ledge Bias that change in high frequency and wide bands. wide bands.s.

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A Slotted Square-Patch Type Balun-BPF (슬롯을 가진 사각 패치형의 발룬-대역 통과 여파기)

  • Oh, Song-Yi;Hwang, Hee-Yong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.11
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    • pp.1208-1213
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    • 2010
  • In this paper, a microstrip balun-BPF of slotted-square-patch type is proposed. The conventional balun-BPF has some drawbacks of narrow bandwidth and high insertion loss. In order to improve these weak points, we used a square patch in designing balun-BPF on which two slots intersecting perpendicularly and one corner-edge perturbation are adopted. This structure allows one of the most effective use of the patch space so that the insertion loss can be decreased. Changing the slot lengths is use to control the operating frequency and the bandwidth of the balun-BPF. A fabricated balun-BPF shows wide bandwidth of 300 MHz(12.7 %), small insertion loss of 0.56 dB, phase difference of $184^{\circ}{\pm}15^{\circ}$ and amplitude imbalances of within 1 dB between two output ports at 2.4 GHz band.

A Study on Traditional Brand Market for Fashion Merchandise in Korea (국내 의류상품의 트래디셔널 브랜드 마켓에 대한 연구)

  • 박송애;이선재
    • Journal of the Korean Society of Costume
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    • v.52 no.2
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    • pp.1-17
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    • 2002
  • The Traditional Look, a class of fashion, represents image based on British aristocratic authenticity and cultural heritage as unchangeable and lasting classic fashion style. And recently, it keeps up with the trend of modern and young consumers' desire by putting various images. The purpose of the study is to investigate the concept, image and present market condition and to analyze degree of consumers' brand awareness of Traditional brand in pursuit of developing new market and ensuring power between competitive brands. From above work, surveyed on degree of brand awareness and interest, preference, associable image and purchase factors coming from consumers. 606 data were analyzed with SPSS package. Frequency, Factor analysis, one-way ANOVA, Multiple response, and correlation were applied. The results of this study were as follows. 1. Traditional brand has a high degree at consumers' brand awareness but comparatively lower at interest in it. In band name, while the Burberry has the highest brand awareness, the Polo and the Hunt take first and second position in a purchasing rate. Brand preference has tendency to be concentrated on certain brands showing the outstanding highest degree like the Polo in the 20s, and the Burberry in the 50s in aspect of age structure. 2. In associable image of Traditional brand, it is associate with noble image as dignified, classical and intellectual with itself strongly among practical, individuality, confidential and noble image. 3. As the purchase factors of traditional brand products, it depends on mainly the reliability and esthetic factors like design and quality rather than ostentatious and practical factors. 4. Associable image except individuality image is correlated with the purchase factors of traditional brand.

Promoter Methylation Status of DNA Repair Gene (hMLH1) in Gastric Carcinoma Patients of the Kashmir Valley

  • Wani, Majid;Afroze, Dil;Makhdoomi, Muzamil;Hamid, Iqra;Wani, Bilal;Bhat, Gulzar;Wani, Rauf;Wani, Khursheed
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.8
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    • pp.4177-4181
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    • 2012
  • Cancer is a multi-factorial disease and variation in genetic susceptibility, due to inherited differences in the capacity to repair mismatches in the genome, is an important factor in the development of gastric cancer (GC), for example. Epigenetic changes, including aberrant methylation of 5/CpG islands in the promoter regions of mismatch repair (MMR) genes like hMLH1, have been implicated in the development of various types of GC. In the present study we evaluated the role of hMLH1 promoter hypermethylation in Kashmiri GC patients and controls, and assessed correlations with various dietary and lifestyle factors. The study included 70 GC patients (56 males and 14 females; age ($mean{\pm}S.D$) $50{\pm}11.4$ years). Distinction between methylated and unmethylated was achieved with MS-PCR and DNA band patterns. The Chi-square test was applied to assess the risk due to promoter hypermethylation. We found a strikingly high frequency of promoter hypermethylation in GC cases than in normal samples (72.9% (51/70) in GC cases vs 20% (14/70) in normal samples (p=0.0001).We also observed a statistically significant association between methylated hMLH1 gene promoter and smoking, consumption of sundried vegetables and hot salted tea with the risk of GC. This study revealed that hMLH1 hypermethylation is strongly associated with GC and suggested roles for epigenetic changes in stomach cancer causation in the Kashmir valley.

MAC Scheduling Algorithm in IEEE 802.15.3 HR-WPAN (고속 무선 개인화 네트워크를 위한 MAC 스케줄링 알고리즘)

  • Joo Sung-Don;Lee Chae-Woo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.6 s.336
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    • pp.41-52
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    • 2005
  • In wireless networks there are various errors, caused by multi-path fading and interference between devices which lower the network Performance. Especially, performance of IEEE 802.IS.3 High-Rate WPAN (Wireless Personal Area Network) which is operated in ISM unlicensed frequency band is easily affected by channel errors. In this paper, we propose a scheduling algorithm which takes channel errors into consideration in scheduling asynchronous data traffic. The proposed scheduling algorithm can allocate CTA(Channel Time Allocation) proportionally in accordance with the requested channel time of each device. It also prevents waste of channel time by allocating CTA of the channel-error devices to other channel-error free devices. After recovering from the channel error, the devices are compensated as much as they conceded during channel error status. Simulation results show that the proposed scheduling algorithm is superior to the existing SRPT(Shortest Remain Processing Time) and RR(Round Robin) in throughput and fairness aspects.

THE DEVELOPMENT OF CIRCULARLY POLARIZED SYNTHETIC APERTURE RADAR SENSOR MOUNTED ON UNMANNED AERIAL VEHICLE

  • Baharuddin, Merna;Akbar, Prilando Rizki;Sumantyo, Josaphat Tetuko Sri;Kuze, Hiroaki
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.441-444
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    • 2008
  • This paper describes the development of a circularly polarized microstrip antenna, as a part of the Circularly Polarized Synthetic Aperture Radar (CP-SAR) sensor which is currently under developed at the Microwave Remote Sensing Laboratory (MRSL) in Chiba University. CP-SAR is a new type of sensor developed for the purpose of remote sensing. With this sensor, lower-noise data/image will be obtained due to the absence of depolarization problems from propagation encounter in linearly polarized synthetic aperture radar. As well the data/images obtained will be investigated as the Axial Ratio Image (ARI), which is a new data that hopefully will reveal unique various backscattering characteristics. The sensor will be mounted on an Unmanned Aerial Vehicle (UAV) which will be aimed for fundamental research and applications. The microstrip antenna works in the frequency of 1.27 GHz (L-Band). The microstrip antenna utilized the proximity-coupled method of feeding. Initially, the optimization process of the single patch antenna design involving modifying the microstrip line feed to yield a high gain (above 5 dBi) and low return loss (below -10 dB). A minimum of 10 MHz bandwidth is targeted at below 3 dB of Axial Ratio for the circularly polarized antenna. A planar array from the single patch is formed next. Consideration for the array design is the beam radiation pattern in the azimuth and elevation plane which is specified based on the electrical and mechanical constraints of the UAV CP-SAR system. This research will contribute in the field of radar for remote sensing technology. The potential application is for landcover, disaster monitoring, snow cover, and oceanography mapping.

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A Study on the Feeding Structure of the High-Temperature Superconducting Hairpin-comb Filter (고온초전도 헤어핀 콤 여파기의 급전 구조에 관한 연구)

  • Yun, Seok-Sun;Park, Ik-Mo;Min, Byoung-Chul;Choi, Young-Hwan;Moon, Seung-Hyun;Lee, Seung-Min;Oh, Byung-Du
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.12
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    • pp.11-20
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    • 1999
  • We have designed and fabricated direct-and gap-coupled microstrip hairpin-comb filters by patterning double-sided YBCO films on a single 50-mm-diameter, 0.5-mm-thick $LaAlO_3$ wafer. Both filters have a center frequency at 1.773 GHz, 12 MHz bandwidth, 0.5 dB minimum insertion loss in the passband, and very strong out-of- band rejection. Due to two attenuation poles below and above the passband, the direct-coupled hairpin-comb filter showed a better skirt characteristic than the gapcoupled hairpin-comb filter which had only one attenuation pole below the passband.

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Broadband 90° Schiffman Phase Shifter Using Slot-Coupled Lines (슬롯-결합 선로를 이용한 광대역 90° 쉬프만 위상천이기)

  • Rhee, Seung-Yeop
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.10
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    • pp.1145-1150
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    • 2012
  • In this paper, an improved Schiffman phase shifter is proposed using slot-coupled lines. It consists of the typical coupled lines and a simple rectangular slot which is placed in the ground plane underneath the coupled lines. Phase responses of the slot-coupled Schiffman phase shifter are analyzed in consideration of the phase velocity of two independent transmission modes and the characteristic impedance of slot-coupled line. The $905^{\circ}$ Schiffman phase shifters with high impedance ratio is realized at 2.4 GHz, which cannot be implemented with the conventional coupled lines. The measured results show that the bandwidth is around 74.2 % within the phase errors ${\pm}5^{\circ}$. The measured return loss is found to be better than 15.0 dB and insertion loss is less than 1.5 dB over the operating frequency band.

Broadband 90° Schiffman Phase Shifter with Vertically Installed Coupled Lines (수직 장착된 결합선로를 이용한 광대역 90° 쉬프만 위상천이기)

  • Rhee, Seung-Yeop
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.7
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    • pp.721-727
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    • 2014
  • In this paper, an broadband Schiffman phase shifter is proposed using vertically installed coupled lines. It consists of the typical coupled lines and a extra coupled lines which is installed vertically on the original coupled lines plane. Phase responses of Schiffman phase shifter with vetically installed coupled lines are analyzed in consideration of the phase velocity of two independent transmission modes and the characteristic impedances. The $90^{\circ}$ Schiffman phase shifters with high impedance ratio is realized at 2.4 GHz, which cannot be implemented with the conventional coupled lines. The measured results show that the bandwidth is 1.5~3.2 GHz(70.8 %) within the phase errors ${\pm}5^{\circ}$. The measured return loss is found to be better than 12.4 dB and insertion loss is less than 1.2 dB over the operating frequency band.