• ETRI Journal
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• v.28 no.5
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• pp.656-659
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• 2006

This letter presents a new polarizer which has a simple comb structure inside a circular waveguide. The electrical performance of the proposed comb polarizer is optimized by a circular waveguide radius and by the physical parameters of the comb plates. This polarizer is suitable for providing good performance in millimeter-band application because of its simple structure and low fabrication cost. In our experiments the dual-band comb polarizer designed in band 1(K) and band 2(Ka) showed good electrical performance without any tuning elements.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.4
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• pp.251-256
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• 1976

Langmuir adsorption maximum was used as a basis for the estimation of phosphate requirement as related to the application method to a newly reclaimed hilly land. The application rates of phosphate fertilizer were 4 levels corresponding to 5, 10, 20, and 30 percent of the Langmuir adsorption maximum which was determined by the laboratory experiment. The phosphate fertilizer was applied in two different methods of broadcast and band application. Yield of soybean on a newly reclaimed hilly land was greatly affected by the amount of phosphate fertilizer and application method. With the same amount of phosphate fertilizer, the soybean yield in the broadcast was always lower than that in the band application even though the yield in the broadcast increased with the application rate up to the highest level of this experiment. However, the yield in the band application showed steep increase up to 20 percent level and then the yield decreased at the highest level. The yield at the rate of 5 percent with the band application was equal to the yield at the rate of 20 percent with broadcast, and the yield at the rate of 10 percent with band application was higher by 17 percent than that in the highest broadcast rate. When manure was applied at the rate of 1000 kg/10a to the plot of the 10 percent band application, the yield was 14.6 percent higher than the yield of the plot of the 10 percent band application without the manure and was equivalent to the yield of the plot of the 20 percent band application.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1141-1154
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• 1996

The para-unitary (PU) M band filter bank, which can beused for M band decomposition, has many useful properties. In this ppaer, attempts have been made to design and and analyze the linear phase para-unitary (LPPU) M band filter bank, which is appropriate to the image coding application. First, we derive a unified coding gain in terms of the correlation in the band, as well as the energy compaction. And M band filter bank has been designed, maximizing the new coding gain. Then, we analyze the image coding performance of the LPPU M band filter bank, such as the energy compaction, the correlation in the band and the entropy. From the analysis, it is shown that the coding gain for LPPU M band filter bank improves, and the coding gain for the LPPU 4 band filter bank approaches very closely to that for LPPU 8 band filter bank, as the length of the filter increases. This fact is also verified by the coding results on the real images.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.68-76
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• 1996

To elucidate the optimum fertilizer level and application method for band application under puddled-soil drill seeding in Jeonbuk series of fluvio-marine alluvial soil at National Honam Agricultural Experiment Station in 1995, using Dongjinbyeo, slow releasing compound fertilizer of 100％ and 80％ to conventional application level was applied totally as basal fertilizer simultaneously with seeding under 3cm and 5cm depth from soil surface in a distance of 4cm from the seeded row. Plant height was taller and tiller number was higher in band application than conventional application but ratio of effective tiller was vice versa. Panicle number was more but ratio of effective tiller ratio was lower in 100％ than 80％ level of band application and they were higher in 3cm than 5cm depth from soil surface. Leaf area index and dry weight was higher in conventional application at early growth stage but was vice versa after maximum tillering stage, and they were higher in 3cm depth at early growth stage but 5cm depth after maximum tillering stage. NH$_4$-N in soil was higher in conventional application at 25 days after seeding but, thereafter was lower than band application and it was higher in 3cm than 5cm depth till 40 days after seeding but was versa, thereafter. Lodging degree was slightly higher in band application, 100％ level and 5cm depth than in their counterparts. Panicle number and grain number per $m^2$ was lower in conventional application than 80％ or 100％ level of band application without significant difference between band application levels or application methods. Yield was higher at 80％ level of band application under 3cm depth than conventional application, but no significantly different among other application methods. Therefore, 80％ level of band application under 3cm depth of soil surface was more effective for puddled-soil drill seeding on the basis of the reduction of application efforts, better plant growth and higher yield in rice.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.208-211
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• 2008

Band-limited filtering will be applied to remove interference resulted from two neighbored channels in the transmission of KOMPSAT-5 X-Band image data. In that case, receiver in ground station should prepare righteous matched filter to avoid huge BER degradation depending on the matched filter of COTS receiver. As an effort to simulate the bandlimited filtering, test filter was designed and manufactured on the basis of main specification for output filter of KOMPSAT-5 satellite. Consequently, 1.8dB of BER degradation was measured at the output of test band-pass filter, but the degradation was downsized up to 0.4dB thanks to the adaptive matched filter of COTS receiver.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.309-315
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• 2010

A dual-band dual-polarized microstrip antenna array for an advanced multi-function radio function concept (AMRFC) radar application operating at S and X-bands is proposed. Two stacked planar arrays with three different thin substrates (RT/Duroid 5880 substrates with $\varepsilon_r$=2.2 and three different thicknesses of 0.253 mm, 0.508 mm and 0.762 mm) are integrated to provide simultaneous operation at S band (3~3.3 GHz) and X band (9~11 GHz). To allow similar scan ranges for both bands, the S-band elements are selected as perforated patches to enable the placement of the X-band elements within them. Square patches are used as the radiating elements for the X-band. Good agreement exists between the simulated and the measured results. The measured impedance bandwidth (VSWR$\leq$2) of the prototype array reaches 9.5 % and 25 % for the S- and X-bands, respectively. The measured isolation between the two orthogonal polarizations for both bands is better than 15 dB. The measured cross-polarization level is ${\leq}-21$ dB for the S-band and ${\leq}-20$ dB for the X-band.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.460-463
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• 2004

There is a trend to replace TWTA of SSPA in S-Band uplink application for satellite operation. KARI developed l20W full S-Band SSPA system in early 2004. This paper covers SSPA system design and its test results. Through tests, nominal gain of 57dB, gain stability of +/-1dB over frequency, and gain stability of +/-0.5dB over temperature were shown. IMD value of -16.5dBc, -19dBc were revealed in PI and P3 output operations. With meeting specifications, l20W SSPA is expected to be used in operational S-Band uplink application.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.250-253
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• 2007

Korean Multi-Purpose SATellite 5 (KOMPSAT-5) will be the first high resolution X-band SAR satellite of Korea. A critical parameter necessary for interpreting SAR images over the ocean is surface wind field. SAR is the only system that can provide a synoptic view of wind fields over the ocean covering large areas. However, there has been no X-band wind retrieval model. In this study, we evaluate the development of an X-band wind retrieval model and show the possibility of KOMPSAT-5 SAR on wind estimations using a combination of theoretical models.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.432-435
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• 2007

In this paper, a dual band microstrip patch Antenna is designed for RFID Application. The antenna shows a good performance at the frequencies, 900MHz and 2.45GHz for the radiation characteristics and input impedance matching, as well. The reflection factor is lower than -25dB and a good directivity higher than 5dB is achieved for both frequency.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.1
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• pp.24-28
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• 2010

This paper is presented on the antenna design for notepc platform. We present the antenna with combination of electric-magnetic radiator for dual-band Wireless Local Area Network (WLAN) service and a High Speed Downlink Packet Access (HSDPA) service. Due to the limited antenna space in notepc platform, the antennas for various wireless communication service should be located at a very small area. In this paper, the magnetic-type radiator works for high frequency band (1.7 - 2.1 GHz) application and the electric-type radiator works for low frequency band (820 - 960 MHz) application. This combination produces wide-band characteristics in the high frequency band. Simulation and experimental results of input impedance and gain characteristics of the proposed antenna are presented. There are good agreements between the simulated and measured S11 and gain values.