• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.9
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• pp.964-970
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• 2002

In this paper, cruciform radiation pattern antenna was designed and fabricated. The fabricated antenna is applicable to intersections which is composed of four eight-lane roads each having 60 m of width and 200 m of length. The design theory was based on Woodward-Lawson method and the 6 monopole elements with the strip feeding network are made by linear array on the micro-strip board. In the results, - 13.5 dB of return loss and 120 MHz(6 %) of -10 dB bandwidth were obtained at the 2 GHz. Also, at 1.95 GHz, -6 dB of gain fall was seen at $\pm$45$^{\circ}$ and thus, it is possible to say that the presented antenna has well-shaped cruciform radiation pattern.

• Journal of Internet Computing and Services
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• v.3 no.3
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• pp.87-93
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• 2002

A complex network and a parallel computer are made up of interconnected switching units. The role of a switching unit is to set up a connection between an input port and an output port, according to the routing information. We proposed our switching network with a remodeled architecture is a newly modified Banyan network with eight input and output ports. We have analysed the maximum throughput of the revised switch. Our analyses have shown that under the uniform random traffic load, the FIFO discipline is limited to 70%, The switching system consists of an input control unit, a switch unit and an output control unit. Therefore the result of the analyses shows that the results of the networking simulation with the new switch are feasible and if we adopt the new architecture of the revised model of the Banyan switch, the hardware complexity can be reduced. The FIFO discipline has increased by about 11% when we compare the switching system with the input buffer system. We have designed and verified the switching system in VHDL using Max＋plusII. We also designed our test environment including micro computers, the base station, and the proposed architecture. We proposed a new architecture of the Banyan switch for BISDN networks and parallel computers.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.1
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• pp.77-83
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• 2011

In this thesis, 50W Doherty amplifier was designed and implemented for Beyond 3G's repeater and base-station. Auxiliary amplifier of doherty amplifier was implemented by Gate bias control circuit. Though gate bias control circuit solved auxiliary's bias problem, output characteristics of doherty amplifier was limited. To enhance the output characteristic relativize Drain control circuit And To improve power efficiency make 3-way Doherty power amplifier. therefore, 3-way GDCD (Gate and Drain bias Control Doherty) power amplifier is embodied to drain bias circuit for General Doherty power amplifier. The 3-way GDCD power amplifier composed of matching circuit with chip capacitor and micro strip line using FR4 dielectric substance of specific inductive capacity(${\varepsilon}r$) 4.6, dielectric substance height(H) 30 Mills, and 2.68 Mills(2 oz) of copper plate thickness(T). Experiment result satisfied specification of amplifier with gains are 57.03 dB in 2.11 ~ 2.17 GHz, 3GPP frequency band, PEP output is 50.30 dBm, W-CDMA average power is 47.01 dBm, and ACLR characteristics at 5MHz offset frequency band station is -40.45 dBc. Especially, 3-way DCHD power amplifier showed excellence efficiency performance improvement in same ACLR than general doherty power amplifier.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.275-282
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• 1986

A series of studies on the properties of clayey terrace soils distributed at the inland (Yeongcheon) and coastal (Yeongjil) regions in Yeongnam district was carried out. On the base of the facts found and already reported about the macro morphological features as well as on pedological characters in micro scale, physicochemical properties, mineralogical characteristics etc., the present study dealt with soil genesis and tried to classify the soils for reasonable use and managements. 1. Although the both regions belonged to "Mesic" soil temperature regime and "red and yellow earths" areas of "Thornthwaite" pedo-climatic diagram, climatic indices as a soil forming factor indicate that the coastal Yeongil had milder than the inland Yeongcheon. 2. All the terrace soils had developed soil profiles with an "Argrllic B". Upyeong soils in Yeongil region had "Argillans" even in the "II B horizons" that possibly be "Paleo-argillic". 3. The bisequum profiles of Bancheon in Yeongcheon and Upyeong in Yeongil revealed that they were developed on Late Mesozoic shale and on semiconsolidated Tertiary deposits respectively, therefore the overlying clayey terrace deposits were assumed to be originated from the Early Quaternary deposits, Diluvium. 4. To supplement the Soil Taxonomy of USDA, the terrace soils with different degrees of gleyzation were classified as follows; Deogpyeong and Hwadong soils which have less than 50cm of paddified gley horizons (redness less than 0.5) in the upper part of the profiles by artificial surface irrigation, tentatively classified into "Anthrepiaquic Hapludalfs" and the Geugrag soils that have more than 50cm of paddified gley horizons within 1.2m of the profiles, into "Anthr-aquic Ochraqualfs" while the Upyeong soils that had greyish mottles in subsoils by natural ground water remain as an "Aquic Hapludalfs" the same as present. The Bancheon soils with free mottles are into "Typic Hapludalfs" as used at present.