• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.7
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• pp.1167-1174
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• 2001

Antenna PIM(Passive Intermodulation) level measurement results are rarely credited due to the external signal receiving characteristics of antenna, and seriously affected by the external PIM sources such as anechoic chamber absorber and antenna tower. In this paper, antenna PIM model for the Reflect PIM measurement method is presented. Through the null point phenomena of the PIM level obtained by antenna PIM model simulations and experimental results, we concluded that antenna PIM level measurements are greatly affected by the PIM level generated on the anechoic chamber absorber and the path differences of PIM signal reflected to the antenna.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3A
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• pp.417-423
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• 2000

A broadband antenna available in the range of 30MHz for electromagnetic interference (EMI) test is proposed in this paper, This antenna is configurated in a disk-loaded cylindrical dipole (DLCD) connected to an 180。 hybrid balun consisting of two coaxial feeders. The performance of EMI antenna is characterized with its accurate antenna factor. The antenna factor for this antenna is obtained by using the method of moments and the calculated results are compared with the measured ones. Normalized site attenuation (NSA) is also measured by using this antenna. The results present that the propose antenna could be used for a reference antenna having measurement reproducibility and represented by a theoretically accurate analysing model in EMI measurement.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.525-528
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• 2005

The tracking antenna system must be always pointed to target moving vehicle. Especially, for an antenna mounted on a movable vehicle, it needs the stabilized antenna system. In this paper, two types of fuzzy controller were derived and applied to a data link antenna system and the altitude control of unmanned helicopter, respectively. A simplified Fuzzy-PID controller was designed for 2-axes antenna stabilization and tracking system and the performance was verified by simulations and experiments. Computer simulations were performed by Matlab and SIMULINK. A 2-Axes antenna (SeaTel 1898 model) was selected as test platform of this research. The antenna was modified by using two Blushless Direct Current motors and an embedded DSP controller. To verify the performance of designed antenna servo control system, the performance of the conventional PID controller and that of the Fuzzy-PID controller, designed by the same PID control gains, were compared.

• ETRI Journal
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• v.27 no.2
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• pp.227-230
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• 2005

A specific anthropomorphic mannequin (SAM) model was used to investigate the relation between local specific absorption rate (SAR) and head size. The model was scaled to 80 to 100% sized models at intervals of 5%. We assumed that the shell of the SAM model has the same properties as the head-equivalent tissue. Five handsets with a monopole antenna operating at 835 MHz were placed in the approximate cheek position against the scaled SAM models. The handsets had different antenna lengths, antenna positions, body sizes, and external materials. SAR distributions in the scaled SAM models were computed using the finite-difference time-domain method. We found that a larger head causes a distinct increase in the spatial peak 1-voxel SAR, while head size did not significantly change the peak 1-g averaged-SAR and 10-g averaged-SAR values for the same power level delivered to the antenna.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.111-120
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• 1996

In this paper, we proposed an inductance loaded small type open-loop travelling wave antenna model for the suitable VHF/UHF frequency bands moisture measurement systems and analyzed its operating characteristics by galerkin's solution method. This antenna model enables to change the oeprating rsonance frequency from the frequency range 150 Mhz to 1.0 Ghz without changing the antenna design dimensions by only varing the load inductance values and it showed the similar operating charcteristics and narrowband resonance characteristics at each resonance frequencies. Also this model showed the uniformly distriubte dpower radiation characteristics above the loop axis and it can effectively suppress the spurious radiations from its narrowband resonance characteristics.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1275-1276
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• 2015

Full wave electromagnetic simulation or fabricated models of an antenna are used to predict its radiation characteristics. In this work estimation of radiated power of an antenna based on its electrical model is presented. The computed radiated power using the electrical model have good agreement with the radiated power results obtained through the full wave electromagnetic simulation of the antenna model. The presented approach offers the advantage of saving of computation time of the full wave EM simulation.

• Journal of electromagnetic engineering and science
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• v.11 no.2
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• pp.122-127
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• 2011

A general analysis of an aperture-coupled vertically mounted strip antenna is presented to examine its circuit characteristics. Based on the present analysis, an equivalent circuit model is developed, and an analytic or semi-analytic evaluation of the related circuit element values is described. The effects of structure parameters on the antenna characteristics were studied with the developed equivalent circuit, and the design curves were obtained. To check the validity of the proposed analysis and design theory, two C-band antennas (5.0 GHz and 4.5 GHz) were designed and fabricated. Their computed characteristics, derived from the proposed network analysis, were compared with the measurement and simulation results. The error of the current model in predicting the operating center frequency was less than 0.50 %. In addition, the observed bandwidth was found to be comparable to the conventional microstrip antennas. All the results fully validated the efficiency and accuracy of the proposed analysis and network model.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.147-150
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• 1999

A T-shaped microstripline-fed printed slot array antenna having wide bandwidth, high gain, and narrow bandwidth is presented in this paper. The proposed antenna is analyzed by using the transmission line model method. We fabricated 4$\times$1 microstrip slot array antenna and measured its return loss and radiation pattern. The maximum bandwidth of this array antenna is from 1.43 ㎓ to 2.60 ㎓, which is 58.1% for the VSWR $\leq$ 2.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.77-81
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• 2001

This paper proposed a novel chip type ceramic dielectric antenna by using the advanced meander line technique that the radiational metals are formed on the face of ceramic dielectric(8 ${\times}$ 4 ${\times}$ 1.5 mm, alumina) and both facses of substrate(1.0 mm thickness, FR-4). The performance of the antenna model has a good agreements between measurements and computed results. Resultly, it has a 10 dB return-loss bandwidth(2.4～2.4835 GHz) and 1.7 dBi measured radiation gain for Bluetooth application. The proposed antenna model can overcome the problems of the radiation gain from the small antenna's size.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.112-115
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• 2016

This paper demonstrates a scalp-implantable miniaturized antenna at the medical implant communication service (MICS) (402-405MHz) band. The antenna size is only $27.63mm^3$($8.5mm{\times}6.5mm{\times}0.5mm$), which is the smallest antenna for the MICS band. Miniaturization is achieved by using a symmetrical serpentine shaped radiating patch and placing open-end slots in the ground plane. In addition, co-axial feeding is used for excitation with a shorting pin connected between the radiator and ground. The antenna was simulated in a homogeneous skin model and in the human scalp. An experimental prototype of the proposed antenna was fabricated and measured in a skin-mimicking gel. Good agreement was obtained between the measurement and simulation results, showing a broad bandwidth of 49 MHz (from 395 to 444 MHz) for |S11| less than -10 dB and a maximum gain of -42.87 dBi. This gain is higher than the previous MICS antenna with respect to antenna size.