• Journal of electromagnetic engineering and science
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• v.15 no.1
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• pp.6-13
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• 2015

In this paper, a novel monopole antenna for WLAN/WiMAX application is presented. The proposed antenna consists of two arc-shaped strips, a vertical strip, and a slot in the ground plane. In this study, a prototype of the proposed triple-band antenna was designed, fabricated, and tested. The quantitative and experimental results demonstrate that the proposed antenna satisfy the -10 dB impedance bandwidth requirement of 440 MHz for 2.4/2.5 GHz bands (from 2.26 to 2.70 GHz), 970 MHz for 3.5 GHz bands (from 3.27 to 4.24 GHz), and 870 MHz for the GHz bands (from 5.08 to 5.95 GHz), while simultaneously covering the WLAN and WiMAX bands. In addition, the presented triple-band antenna has an omnidirectional radiation pattern at all three frequency bands with an antenna gain of 4.45 dBi for the lowest band, 2.04 dBi for the middle band, and 3.98 dBi for the highest band.

• Journal of electromagnetic engineering and science
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• v.3 no.1
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• pp.23-28
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• 2003

In this paper, a triple-band planar antenna is proposed for the application to miniaturized automobile safety devices operating at X band(10.5 ㎓), K band(24.15 ㎓), and Ka band(34.3 ㎓). The frequency ratio between the resonant frequencies of this antenna can be adjusted from 1.99 to 2.23 for both X band and K band by varying its slit length. Parasitic elements are added on the modified slot loaded antenna to obtain the third resonance. From numerical as well as experimental results, it has been confirmed that this type of antenna is appropriate for planar multi-band antenna systems.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.385-386
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• 2008

In this paper, a simple dual band filter chip is designed with 0603 case size using IPD technology. The dual-band filter achieves high frequency band at 2.5 GHz and low frequency band at 1.8 GHz. The insertion losses in high frequency band and low frequency band are -0.195 dB and -0.146 dB, respectively. The return losses in these bands are -22.7 dB and -22.8 dB, respectively. The simple dual-band filter based on SI-GaAs substrate is designed within die size of about 1.3 $mm^2$.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.27 no.3
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• pp.17-24
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• 2021

Background: The study aimed to examine changes in muscle activity by measuring the Q-angle and lower extremity activity when going down the stairs, after the application of either Mulligan taping or flossing bands to patients with chronic ankle instability. Methods: A total of 19 men with chronic ankle instability in their 20s and 30s participated in the study. Participants were randomly divided into two groups: the Mulligan taping group (n = 9) and the flossing band group (n=10). The Mulligan taping group had three sets of Mulligan joint operations repeated 10 times, after which the Mulligan tape was applied. The flossing band group either performed functional activities or exercised for 2 minutes after flossing band application. After the application of either Mulligan taping or flossing bands, changes in the Q-angle and lower limb muscular activity while going down the stairs were measured and compared. Results: In the Mulligan taping group, the Q-angle significantly decreased from 13.63° to 12.7° during the step down. Similarly, the Q-angle of the flossing band group significantly decreased from 15.95° to 15.48° (p<.05). There was no difference in lower limb muscle activity between the two groups when going down the stairs. The muscle activity of the tibialis anterior significantly increased from 34.12% to 40.2%, and the difference between the two groups were statistically significant (p<.05). Conclusions: The study found that the application of Mulligan taping and flossing bands to patients with chronic ankle instability decreased the Q-angle and lower limb muscle activity when going down the stairs.

• Journal of Advanced Navigation Technology
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• v.15 no.2
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• pp.197-203
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• 2011

A triple-band antenna which can be used at GSM900, PCS1900 and Bluetooth(or Wi-Fi) frequency band is proposed. The proposed antenna is designed based upon switching between IFA(Inverted F Antenna) that has a resonant length of ${\lambda}/4$ and loop antenna that has a resonant length of ${\lambda}/2$. It can be applied to triple-band only by use of single printed pattern due to the switching characteristic. It is designed by use of the IFA for the application to the GSM900, while it is designed by use of the loop antenna for the application to the PCS1900 and by use of additional pattern of IFA for the application to the Bluetooth(or Wi-Fi) respectively. As a result, it has been observed that the proposed antenna satisfies the required return loss(${\leq}10dB$) and also has efficiency(${\geq}80%$) over the whole band. Moreover the proposed antenna has omni-directional radiation pattern which is suitable to apply to the mobile phone.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.192-195
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• 1997

The deformation of the rotating band is simulated to improve the original design of the rotating band. The improved designs are proposed by referring the result of the finite element analysis. A new experimental technique is proposed and its application has been carried out to show the validity of the result of the analysis and the performance of the improved design of the band.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.332-335
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• 2008

Newly developing SAR (Synthetic Aperture Radar) sensors commonly include high resolution X-band those data are expected to contribute various applications. Recent few studies are presenting potential of X-band SAR data in forest related application. This study tried to investigate the relationship between forest stand parameters and multi-band SAR normalized backscattering. Multi-band SAR data was radiometric corrected to compare signal from different forest stand condition. Then correlation coefficients were estimated between attribute of forest stand map and normalized backscattering coefficients. Although overall correlation coefficients are not high, only X-band shows strong relationship with DBH class than other bands. The signal of C- and L-band is composed of a large number of discrete tree components such as leaves, stems, even background soil. In forest, strength of radar backscattering is affected by complex parameters. Further study might be considered more various forest stand parameters such as canopy density, stand height, volume, and biomass.

• Journal of the Korean Ceramic Society
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• v.31 no.1
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• pp.11-16
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• 1994

The impedance matching solution map is not a sufficient method for designing the broad-band absorber because of its difficulty to get numerical data about practical band-width. Therefore, we develope a new method to design the broad-band absorber. The complex permeability limits, which is necessary for designing the broad-band absorber in C-X band (4 GHz~12.4 GHz) were investigated and application was also examined. The complex permeability limits represent the frequency dependence of the complex permeability at a practical frequency band. These complex permeability limits can be used effectively to design broad-band single-layered absorber because they offer numerical data about the band-width in the case of various dielectric loss tangent, practical frequency bands and permitted reflection losses of an absorber.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.533-534
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• 2008

This paper presents a multi-phase ring VCO for low-cost, low-power GPS receiver. In the RF band used in GPS, L1 band is now in commercial-use and L2,L5 are predicting to be commercial-use soon. Thus Wide band PLL and Cost-effective IC solutions are required for future multi-band GPS receiver that received three types band at once. A new PLL architecture for multi-band GPS application is proposed. Ring VCO is even smaller than LC-VCO and a good alternative for low-cost solution. Proposed multi-phase ring VCO offers wide frequency range covering L1, L2, and L5 band, 20% reduction of area, 23% reduction of PLL power and can generate I/Q without extra I/Q generator.

• Journal of electromagnetic engineering and science
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• v.16 no.2
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• pp.100-105
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• 2016

We have designed a three-channel output multiplexer (OMUX) using a band-pass filter and an ultra-wideband (UWB) antenna. The proposed band-pass filter is composed of an inner rectangular loop, an outer open stub, and a defected ground structure. The outer open stub can be used to control the pass band, and the inner rectangular loop can improve the insertion loss characteristics of the band-pass filter. The proposed band-pass filter, UWB antenna, and OMUX are fabricated and measured. The designed OMUX can cover the band group 1 (3,168-4,752 MHz) of WiX system. The measured radiation patterns are close to those of a conventional dipole antenna and the measured antenna gain varies from 1.8 dBi to 3 dBi over the operating frequency range.