• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.790-794
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• 2012

A output strength is limited according to the frequency used in order to protect other wireless stations from interference caused by radio waves emitted from the low power wireless installations. For receivers, unwanted spurious emission is regulated, and regulations in Korea define that additional spurious emission for receivers in the low power wireless installations under 1GHz should be -54dBm, but no regulations have been established yet for low power wireless installations over 1GHz. It is presently required to set domestic standards for devices over 1GHz on account of the expansion of the communication market and its service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.963-965
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• 2009

For the low power wireless installations, limited frequency resources are divided by use for their effective use and are assigned. Moreover, output strength is limited according to the frequency used in order to protect other wireless stations from interference caused by radio waves emitted from the low power wireless installations. For receivers, unwanted spurious emission is regulated, and regulations in Korea define that additional spurious emission for receivers in the low power wireless installations under 1GHz should be -54dBm, but no regulations have been established yet for low power wireless installations over 1GHz. It is presently required to set domestic standards for devices over 1GHz on account of the expansion of the communication market and its service.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.1
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• pp.176-179
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• 2006

As spurious emission strength is normally measured at the antenna feeder, It is required that the measurement method on passive Intermodulation occurred on the latter part of antenna feeder be made. through the tests and the analyses of passive Intermodulation between radiostations of adjacent frequency bands, the possibility of occurrence of passive Intermodulation was testified in this study. The purpose of this study is to propose the measurement method of spurious emission strength in order to prevent the bad effect by passive Intermodulation.

• Journal of IKEEE
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• v.17 no.1
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• pp.10-15
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• 2013

This paper, we analyzed that the measured data of the radiated power spectrum of electromagnetic waves of the normal spark ignition system and the spark ignition system with feed through type ceramic condenser. The results show that the strength of power spectrum radiated from the system with feed through type ceramic condenser is weaker than the normal system, and the density of power spectrum radiated from the system with feed through type ceramic condenser is smaller than the normal system. From these results, the feed through type ceramic condenser can reduce the electromagnetic waves radiating from the spark ignition system which is the spurious emission, and it can be concluded that the ignition coil of the spark ignition system generating high voltage pulse is equivalent to the radio frequency oscillator which is oscillating high frequency from a electronic point of view.

• Journal of Convergence for Information Technology
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• v.10 no.8
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• pp.47-52
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• 2020

In this study, a simulation investigation was conducted on the method of reducing switching noise and spurious emission among design methods for step-down DC-DC converter modules for automotive. A typical 4-layer converter circuit using a PMIC(Power Management Integrated Circuit) chip was presented, and the simulation results of conductive emissions at two input terminals (+, -) and the point between the input filter and the PMIC was performed in the 1.0~5.0MHz band and the 100MHz band. The results for the conducted and radiated emissions in the HF(3~30MHz) and VHF(30-300MHz) bands were presented. It showed an improvement of about 10dB over the bands by routing the output terminal placed on the 3 or 4-layer in the opposite direction to the input terminal. The result of this study is expected to be useful in the design of the DC-DC converter modules in the future because it gives a better improvement compared to the existing methods.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.600-613
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• 1997

The implementation of a BTS(Base station Transceiver) for WLL system using W-CDMA(Wideband-Code Division Multiple Access) method is presented in this paper. It consists of three boards; receiver, transmitter and RF controller. Some RF parameters are considered and simulated by the RF simulation S/W using commercial and customized components specifications. The implemented transceiver of 5 MHz RF channel bandwidth satisfies the system requirements of a transceiver such as dynamic range, sensitivity in the receiver and spurious emission suppression in the transmitter. At the receiver, the experimental measurement showed 2.86 dB of NF and 60 dB above of dynamic range in AGC(Automatic Gain Control) locking. At the transmitter, the -49.46 dBc of spurious emission suppression is attained when the output power of the transmitter is 34.3 dBm. These results are good enough to meet to standard performance specifications.

• Journal of Sensor Science and Technology
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• v.25 no.1
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• pp.8-12
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• 2016

A planar, light-weight, and low-cost notch filter structure is required for the KSTAR ECEI (Electron Cyclotron Emission Imaging) system to protect the mixer arrays from spurious plasma heating power. Without protection, this heating power can significantly degrade or damage the performance of the mixer array. To protect mixer arrays, a frequency selective surface (FSS) structure is the suitable choice as a notch filter to reject the spurious heating power. The FSS notch filter should be located between the lenses of the ECEI system. This paper presents a 170 GHz FSS notch filter for the KSTAR ECEI sensor application. The design of such an FSS notch filter is based on the single-sided square loop geometry, because that makes it relatively insensitive to the incident angle of incoming wave. The FSS notch filter exhibits high notch rejection with low pass-band insertion loss over a wide range of incident angles. This paper also reviews the simulated and measured results. The proposed FSS notch filter might be implemented in other millimeter-wave plasma devices.

• Smart Structures and Systems
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• v.8 no.4
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• pp.385-398
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• 2011

This paper discusses the applicability of Acoustic Emission (AE) to assess the damage in reinforced concrete (RC) structures subjected to complex dynamic loadings such as those induced by earthquakes. The AE signals recorded during this type of event can be complicated due to the arbitrary and random nature of seismicity and the fact that the signals are highly contaminated by many spurious sources of noise. This paper demonstrates that by properly filtering the AE signals, a very good correlation can be found between AE and damage on the RC structure. The basic experimental data used for this research are the results of fourteen seismic simulations conducted with a shake table on an RC slab supported on four steel columns. The AE signals were recorded by several low-frequency piezoelectric sensors located on the bottom surface of the slab. The evolution of damage under increasing values of peak acceleration applied to the shake table was monitored in terms of AE and dissipated plastic strain energy. A strong correlation was found between the energy dissipated by the concrete through plastic deformations and the AE energy calculated after properly filtering the signals. For this reason, a procedure is proposed to analyze the AE measured in a RC structure during a seismic event so that it can be used for damage assessment.

• Journal of electromagnetic engineering and science
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• v.3 no.1
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• pp.7-11
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• 2003

CDMA(code division multiple access) has very large peak to average power ratio(PAR) and behave as noise-like wide band digital signals with 1.2288 Mbps transmission rate. For signals with high PAR like CDMA, it is reasonable to prescribe occupied bandwidth(OBW) as average occupied bandwidth. Bandwidth measurements of CDMA signals at remote site are affected by co-channel and adjacent channel interference from adjacent CDMA base station, distortion of signal by fading effect, spurious emission and environment noises. In this study, we have compared OBW measurements in an on-air environment with those measured in a base station using adjacent channel leakage ratio(ACLR) as a reference measurement factor. As results of analysis, the OBW at ACLR$\geq$35 ㏈ shows nearly same statistical characteristics regardless of the measurement locations and environments.

• Environmental and Resource Economics Review
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• v.10 no.4
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• pp.619-632
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• 2001

The purpose of this study is to test the Kuznets Hypothesis on the relationship between environmental pollution and economic growth by using the panel data. The major results of the study can be summarized threefold as follows. First, previous studies can pose the risk of spurious regression because of the nature of non-stationery of the data used. Second, the result of the co-integration test indicates that the emission of $CO_2$ and per capita income are co-integrated. Finally, according to the results of OLS and DOLS estimation, the turning point in this study is set in far higher level of per capita income compared with those in previous studies.