• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.263-267
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• 2009

Cylindrical monopole antenna is one of most promising candidates for multi-band applications such as PCS, WLAN, DMB, and UWB wireless services. In this research, we demonstrate that there exist two types of current distributions according to the exciting frequency in a double band cylindrical monopole antenna, in which double resonance is achieved by adjusting the coupling structure of the antenna base. The operating modes of current distributions are identified from CST software simulations, the standing wave mode in a lower band and the traveling wave mode in a higher band. Also it is noticed that the mode behavior is quite similar to a helical antenna, a standing-wave (resonance) mode and a traveling-wave (non-resonance) mode according to the electrical dimensions of antenna. The effective ranges for operating modes and design formulas of the double band antenna are derived from simulation and measured results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.135-138
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• 2009

Cylindrical monopole antenna is one of most promising candidates for multi-band applications such as PCS, WLAN, DMB, and UWB wireless services. In this research, we analyze the current distributions of operating modes for a cylindrical double-resonant monopole antenna. Two modes, the standing wave mode in a lower band and the traveling wave mode in a higher band, are identified from CST software simulations. Finally, design formulas are derived form the simulation results.

• Journal of electromagnetic engineering and science
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• v.7 no.3
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• pp.138-146
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• 2007

In this paper, a monopole antenna of conical-cylindrical compound shape is presented. The conventional circular conical monopole antenna is modified by placing a cylinder at the top of the inverted cone. The cylindrical portion is useful in the wide band impedance matching, in adjusting the antenna gain in the horizontal direction, and in reducing the cone diameter. The dependence of the antenna performance on various geometric parameters is investigated using a commercial electromagnetic simulation software, from which an optimum design of the antenna is derived. The diameter of the circular ground plane is minimized to 115 wavelength at the lowest operating frequency. The antenna proposed in this study shows a reflection coefficient less than -10 dB and a 1${\sim}$6 dBi gain over 3${\sim}$20 GHz frequencies. The antenna shows a circular-symmetric radiation pattern in the horizontal plane and a null-free pattern in the vertical direction over the whole operating frequency range.

• Journal of electromagnetic engineering and science
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• v.7 no.2
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• pp.69-73
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• 2007

A new wideband cylindrical monopole antenna is presented for multiple band applications. Multiple band property of the proposed antenna is achieved by adjusting the coupling structure with steps between the antenna base and the ground plane. The measured -10 dB impedance bandwidths are $1.74{\sim}3.06GHz\;and\;5.59{\sim}10.62GHz$, which can cover various kinds of wireless services, such as $PCS(1.75{\sim}1.87GHz),\;IMT-2000(1.92{\sim}2.17GHz),\;WiBro(2.3{\sim}2.39GHz),\;WLAN(2.412{\sim}2.483GHz,\;5.725{\sim}5.825GHz),\;DMB(2.63{\sim}2.655GHz)$, High-band $UWB(7.2{\sim}1.02GHz)$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1024-1029
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• 2003

This paper presents the complex antenna factor of a top-hat EMI monopole antenna for measuring time domain electromagnetic fields. The approach is facilitated by adding a artificial parallel ground plane above the monopole antenna. This allows use of cylindrical harmonic field expansions in each of three subregions enclosed by the two ground plane. The results show that the complex antenna factor of the top-hat monopole antenna does not diverge at low frequencies. When compared with a monopole antenna, the top-hat monopole antenna has broadband characteristics. In order to verify the availability of the mode-matching method, the input impedance of the antenna were compared with experiments.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.6 no.4
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• pp.267-271
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• 2013

A new structure of double-resonant cylindrical monopole is proposed for multiple band applications. Multiple band property for the proposed antenna is achieved by adjusting the coupling structure of the antenna base for a double resonance. Measured results of the proposed antenna are compared with those of wire and thick cylinder monopoles.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.22-29
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• 2013

The combined structure of both an annular dielectric resonator and a quarter-wave monopole is proposed to generate an omnidirectional radiation pattern over the wideband frequency range. The monopole works at the lower frequency band and excites the cylindrical dielectric resonator along its center point by electrical coupling mechanism. The rectangular shape of the DR is cut to generate the wideband operation of 4.7-18.2 GHz. The geometrical parameter of cylindrical dielectric resonator is 5.8 mm, 11.6 mm and 6.0 mm in inner diameter, outer diameter and height, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.584-587
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• 2007

PCS를 비롯하여 WLAN, DMB, W-CDMA, UWB 등의 무선통신 서비스가 증가함에 따라 안테나 동작 대역폭의 광대역화가 더욱 요구된다. 1/4 파장 선형 모노폴 안테나는 구조가 간단하고 전방향성을 갖는 복사특성으로 인하여 가장 널리 사용되는 안테나 중의 하나이다. 모노폴 안테나의 광대역화를 위해서 일반적으로 원통의 직경을 증가시키는 방법을 사용하지만, 평면 모노폴에 적용된 스텝 기법을 적용하여 광대역 특성을 얻을 수 있다. 그러나 스텝 모노폴 자체는 광대역 특성을 나타내지 않으며, 접지면에서도 일정 형태의 스텝 돌출부위가 필요하게 된다. 본 논문에서는 그라운드면의 볼록 계단 구조가 모노폴 안테나의 대역 특성에 미치는 영향을 분석하여 최적의 안테나 급전구조를 도출하고자 한다. 결과의 검증을 위해서 소프트웨어 시물레이션 및 측정결과를 제시한다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.473-477
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• 2003

In this paper, a integrated structure of a two-element microstrip patch antenna with two feeds for GPS/PCS dual-band operation is proposed. The radiating element for PCS operation is a novel broad band low-profile cylindrical monopole top-loaded with a shorted meander patch, which gives linearly polarized conical radiation pattern and size reduction of patch due to meander line. The radiating element for GPS operation is a novel square-ring microstrip patch with truncated corners and slits. which provide circularly polarized broadside radiation patterns and size reduction due to slots. using dielectric substrate in GPS antenna of proposed antenna provide to improve isolation between two feeds and reduce size of patch. The proposed antenna achieves the bandwidth and polarization requirements of GPS and PCS systems.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.1
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• pp.70-74
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• 2015

In this paper, we have illuminated the radiation modes of rectangular planar antennas to interpret the nature of the wideband characteristic upon which formulas for bandwidth prediction are presented. Rectangular planar antennas are being investigated by many researchers in virtue of relatively simple design and fabrication procedures to replace the cylindrical monopoles. But the design principle for rectangular planar antennas is still based on that of cylindrical monopoles, and the nature of the wideband characteristic and the formula to estimate the upper band frequency are not analyzed yet. In this research, we have shown the patterns of the radiation modes explaining the wideband characteristic and also proposed the upper band frequency with minor modification for the lower band frequency formula based on mode formation principles. Finally we have confirmed the validity of our results, within 10 % accuracy, by the application to some published results.