• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.106
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• pp.287-294
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• 2006

In the paper, characterization and analysis of UWB(Ultra Wide Band) antennas in time domain are described. The impulse propagation channel including UWB antennas is proposed for the analysis in time domain. Using the proposed propagation channel, the technique of obtaining impulse response of UWB antenna is proposed. Also, ringing, peak value of the impulse response, and the width of the impulse response are introduced as parameters for characterizing a UWB antenna in time domain. A modified UWB conical monopole antenna, a UWB TEM horn antenna, and a UWB stepped fat monopole antenna were fabricated. From the measurement of reflection coefficients, three antennas had bandwidth more than 3 GHz. The impulse responses of the antennas were measured in an anechoic chamber. The results showed that the TEM horn with highest gain has the highest peak amplitude and the stepped fat monopole antenna with narrowest bandwidth for reflection coeffcient had the widest width of the impulse response. Also, ringing in the stepped fat monopole antennas and the UWB conical monopole antenna were observed.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.55-59
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• 2021

Generating electromagnetic waves with Orbital Angular Momentum (OAM) properties is a fast-growing research subject in both radio and optics. This paper describes the generation of OAM carrying waves using a circular array of rectangular planar monopole antennas. The proposed design combines simplicity, compactness, and most importantly very wideband of operating frequencies (about 20-160 GHz, bandwidth ratio about 1:8) which makes it suitable for future applications.

• Journal of Advanced Navigation Technology
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• v.16 no.5
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• pp.766-772
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• 2012

In the present study, wideband microstrip monopole slot antennas which can be applied to the RF4CE Zigbee remote controller are designed. First I-shaped monopole slot antenna which has ${\lambda}g/4$ length at 2.45GHz is designed. In particular, a conducting via is used to connect the microstrip feed line and the ground plane surrounded with the etched slot for the bandwidth improvement. In order to reduce the antenna size, it is changed into L-shaped and T-shaped monopole slot antennas for which improve results of antenna performance are observed. In case of T-shaped monopole slot antenna, impedance bandwidth(VSWR<2) is about 3.32GHz, and also its radiation efficiency and gain is more than 90% and 2.1dBi respectively at whole operating frequency range. In particular, all of proposed monopole slot antennas have the end-fire radiations which has a maximum radiation power toward direction of open ends of monopole slots.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.11
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• pp.1121-1127
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• 2014

In this paper, a planar frequency reconfigurable antenna is proposed with variable capacitors. The proposed one is designed with a planar monopole, and varies resonant frequencies by variable capacitive loading of a varactor diode. The equivalent circuit and electromagnetic(EM) simulation are utilized for the analysis at the variable characteristic design of the antenna, and the same radiation performance. The implemented frequency variable monopole antenna has been verified by comparing prototypes with designed capacitors and ones with biased varactor diodes. The proposed antenna has presented the resonant frequency variations from 2.25 GHz to 2.42 GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.797-804
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• 2014

The experimental design method based-on the measured data in the several LF monopole antenna was used in MF monopole antenna design. The design technique is also utilized in MF DGPS antenna design. It is not possible to predict the antenna performance of the MF short-monopole antenna because of simple experimental antenna design. Furthermore, it is difficult to design and analyze the various wired short-monopole antenna. The antenna models for performance analysis of the DGPS antenna with the various wired short-monopole structure are proposed in this paper. Based on the proposed antenna models, also, the antenna performance and design data of the wired short-monopole antennas are presented. To evaluate the validity of the analyzed antenna models, the wired short-monopole antenna for 100 kHz are modeled and analyzed. The antenna performance of the wired short-monopole antenna are compared with those of the previously presented LF antenna performance. Based on the evaluation for proposed antenna analyzing models, the DGPS wired short-monopole antennas are modeled and analyzed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.9
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• pp.727-731
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• 2012

This paper dealt with the measurement and analysis of electromagnetic waves radiated from a partial discharge (PD) source in insulation oil to apply condition monitoring of oil-immersed transformers. Two types of narrow-band monopole antennas with the resonant frequency of a 500 MHz and a 1 GHz were designed and fabricated. Also, a needle-plane electrode system was manufactured to simulate PDs and the curvature radius of the needle is 10 ${\mu}m$ and the diameter of the plane is 60 mm. Electromagnetic wave was measured by the PD measurement system with the monopole antennas. Detection sensitivity of the fabricated antenna was compared for the same PD magnitude; 620 $mV_{peak}$ for the 500 MHz antenna and 960 $mV_{peak}$ for the 1 GHz antenna to the PD magnitude of 74 pC. Consequently, the 1 GHz monopole antenna is more effective to detect PDs in oil-immersed transformers.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.9
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• pp.60-66
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• 2008

In this paper, the CPW-fed Ultra-wideband antenna is designed and fabricated for UWB communications. To achieve ultra-wide bandwidth of the antenna, we propose the mutual coupling of two planar monopole antennas. The mutual coupling of monopole pair of the proposed antenna is optimized by adjusting the parameters, the widths of the planar monopoles and the space between two monopoles. Two UWB antennas with different horizontal sections of the CPW-fed monopole antenna are fabricated and measured to examine the mutual coupling effects on the monopole pair antenna. The measured result show that two antennas are satisfied with UWB communication band(3.1$\sim$10.6Ghz).

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.550-554
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• 2003

In order to detect very short electromagnetic pulses (EMP) with picosecond width, a receiving antenna with a wide bandwidth and good sensitivity over several GHz is needed. In this paper, the receiving characteristics of various thin wire monopole (or dipole) antennas with nonreflecting resistive loading are analyzed for determining the optimum configurations. This study also indicates that it is possible to choose an ideal load impedance for achieving the required fidelity and sensitivity. The analysis is facilitated by introducing the frequency transfer function.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.307-312
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• 2005

In this paper, the broadband FCMA(Folded Cross Monopole Antenna), which is the cross monopole antenna with the folded element, is presented. To investigate the broadband characteristics of FCMA the VSWR, the gain, and the radiation pattern are calculated in frequency between 1.75 GHz and 2.655 GHz. From the calculated result, it is shown that the presented folded cross monopole antenna has a excellent band characteristics than the existing cross monopole antenna. The presented antenna is conformed as a broadband antenna which can be used for the indoor antenna of PCS, WCDMA, Wibro, and satellite DMB band.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6839-6845
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• 2015

The optimization design method for the broadband operation of the sleeve monopole was proposed to unify the multiple antennas essential to the multi-functional broadband wireless communication systems into one antenna. The structure of the sleeve part was optimized to enhance the impedance matching characteristics based on the theoretical analysis that sleeve part can works as the open stub. The thick monopole was used for the broadband operation. The radius of the sleeve and the permittivity of the dielectric inside the sleeve was optimized to enhance the impedance matching characteristics for the broadband operation. The optimized sleeve monopole having thick monopole shows broadband characteristics over 3:1 bandwidth, from 0.8 to 2.43 GHz, which is suitable for the commercial wireless communication system. The proposed broadband sleeve monopole can reduce multiple antennas essential to the multi-functional broadband systems to one antenna.