• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.247-252
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• 2000

In this paper, we discuss frequency allocation and sharing for high speed radio access network in domestic 5㎓ the band. In order to evaluate the possibility of frequency sharing between meterological radar and high speed radio access network we analyses radio interference of meterological radar by means of minimum coupling loss method and Monte Carlo simulation And simulations show that it is necessary to use DFS(Dynamic Frequency Selection) scheme for frequency sharing between meterological radar and high speed radio access network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.4
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• pp.751-758
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• 2000

In this paper, we discuss frequency allocation and sharing for high speed radio access network in domestic 5GHz the band. In order to evaluate the possibility of frequency sharing between meteorological radar and high speed radio access network, we analyses radio interference of meteorological radar by means of minimum coupling loss method and Monte Carlo simulation. And simulations show that it is necessary to use DFS(Dynamic Frequency Selection) scheme for frequency sharing between meteorological radar and high speed radio access network.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.11-18
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• 2021

The small radio frequency tracking radar is a tracking system with a radio frequency sensor that identifies a target through all-weather radio frequency signal processing for a target and searches, detects and tracks the target for the major target. In this paper, we describe the development of a board equipped with TMS320C6678 and XILINX FPGA (Field Programmable Gate Array), a high-speed multi-core DSP that acquires target information through all-weather radio frequency and identifies a target through real-time signal processing. We propose DSP-FPGA combination architecture for DSP and FPGA selection and signal processing, and also explain the design of SRIO for high-speed data transmission.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.68.2-68.2
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• 2014

High Frequency Peakers (HFPs) are radio-loud Active Galactic Nuclei (AGN), which are regarded as being in the earliest evolutionary phase (102-103 years) of radio galaxies. They are expected to be small in size (< ~1 kpc) compared to their host galaxies (~a few 10s kpc), and have convex spectra, which are peaking at high radio frequency (> 5 GHz). Their size and spectral shape are the most obvious supporting evidence of extremely young ages. HFPs are therefore ideal targets to probe the earliest stage of radio sources. To date however, the young radio source classification has been relying mainly on the spectral shape which usually does not cover high enough frequencies where the true peak flux is located. Hence HFPs are often confused with blazars which may show a similar spectral shape and apparent compactness but are a somewhat evolved form of AGNs. Therefore, we have been challenging to identify HFPs among the sample of 19 candidates using the Korean VLBI Network (KVN) which enables us to extend the radio spectrum baseline up to 22 and 43 GHz. These are higher than the frequencies used in most previous studies of HFPs, allowing us to select genuine HFPs. By long-term monitoring of 18 epochs, we have also inspected the variability of the sample to select out blazars which are highly variable yet with a similar radio spectrum. In this work, we present the light curves and spectral properties of the HFP candidates. We discuss the results of our re-identification of HFPs.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.49-54
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• 2012

There is a possibility that electrical sparks may occur at discontinuities in metallic structures from distance of close to high power radio/radar transmitters. Voltage may be induced on these metallic structures by the radio-frequency transmitter. In this case, a person who comes into contact with these structure may be undergone a severe electrical shock. In this paper, assessment of the electrical shock and ignition hazards was investigated through experimental which are consisted radio transmitter and metallic loop-type structure in shield room. We measured that the induced voltage was highest at 61 MHz of transmission frequency, and confirmed the possibility of electric shock and explosion induced by a voltage or spark. But it is needed additional research where is opened site.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.372-376
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• 2004

Digital memory circuits have been developed very fast according to the progress of semiconductor technology But It was very difficult to memorize a high frequency radio signal. Many years ago an analog loop was used for store of radio frequency signal, and the digital radio frequency memory was made to the development of wideband amplifier and high speed sampler. We present a design of wide-band DRFM using Johnson code and the simulation results with respect to the sampling speed. in this paper.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.401-406
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• 2005

Digital memory circuits have been developed very fast according to the progress of semiconductor technology. But it was very difficult to memorize a wideband radio frequency signals. Many years ago, an analog frequency memory loop(FML) was used for store of radio frequency signal and the digital radio frequency memory was made according to the development of wideband amplifier and high speed sampler. We present a design of wideband digital radio frequency reproduction device using ladder circuit and the simulation results with respect to the sampling speed in this paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8A
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• pp.846-851
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• 2008

With rapid development of communication industry, the kinds of communication service vary. According to the increasing use of radio waves, the intelligent and effective radio monitoring system needs to be developed, which is replaced for previous radio monitoring system. Next-generation intelligent radio monitoring system based on ITU-R, Rule of wireless facilities, and Radio Waves Act is used, and which can accurately and effectively function as effective radio monitoring system through spectrum analysis of channel power, frequency deviation, offset, and an occupied frequency bandwidth(99% or x-dB), about the analog and digital signal in On-Air of V/UHF bandwidth. Main function of the system has an radio quality measurement, unwanted electromagnetic signals (spurious, harmonic) measurement, high-speed spectrum measurement, frequency usage efficiency investigation, illegal radio exploration, working monitoring, In this paper, we proposes radio quality measurement, high-speed spectrum measurement of next-generation intelligent radio monitoring system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.348-351
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• 2000

In order to enact the technical standard of RF(Radio Frequency) in domestic, this paper analyzes the trends and the technical specifications of high performance radio local area network, for example HIPERLAN(Europe), U-Nll(U.S.A), broadband mobile access system(Japan). The contents of this paper are helpful to make a rule for the desirable national technical standard of high performance radio local area network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12A
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• pp.1014-1022
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• 2009

In this paper, interference analysis is carried out to obtain the operating criterion and coexistence condition between digital television devices and cognitive radio-based mobile wimax devices in the UHF (Ultra High Frequency) broadcasting frequency bands. To this end, an efficient interfering calculation tool known as SEAMCAT (Spectrum Engineering Advanced Monte-Carlo Analysis Tool) is employed to acquire the coexistence criterions between heterogeneous radio links operating in the same portion of spectrum. As a result, these criterions will be used to achieve interference temperature limit level applied to interference temperature model for analyzing the capacity of cognitive radio receivers accurately.