• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.5
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• pp.773-781
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• 2000

We proposed an eccentric annular ring microstrip slot antenna for improving a narrow bandwidth of the conventional annular ring microstip slot antenna. The proposed antenna has an asymmetric slot and a normal microstrip feedline. This antenna is analyzed and optimized by using the finite difference time domain (FDTD) method. The impedance bandwidth of the optimized antenna is more than 1 octave that is much broader than the conventional annular ring microstrip slot antenna for the same size.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.4
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• pp.351-356
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• 2009

A dual-mode annular ring antenna for both global positioning system(GPS) and satellite digital multimedia broad-casting(DMB) is designed. The proposed antenna consists of a coupling feed line and four slots on the annular ring patch. The gap between the feed line and the annular ring patch is used for an input impedance matching, and the slot length is used for adjusting the resonant frequency of the $TM_{21}$ mode at the DMB frequency. The antenna was fabricated and measured. The experimental results show that the antenna resonants at the GPS and DMB frequencies with suitable bandwidths, and had a broadside radiation pattern at the GPS band and a conical beam radiation pattern at the DMB band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.1
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• pp.75-80
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• 2003

This paper presents novel compact circularly polarized(CP) operation of a annular ring slot antenna with a 45$^{\circ}$truncated in the patch and a cross-slot of unequal slot lengths. A simple configuration based on a cross-slot of unequal slot lengths on the annular ring patch is adopted to realize a small-size element antenna and used a proximity coupled feed method. Experimental results show that much wider impedance bandwidth of 7.74 % and axial ratio bandwidth of 1.9 % in GPS band(1.5 GHz).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.1940-1945
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• 2006

The small and wideband annular ring slot antenna with eccentric radiating structure and low impedance feedline is presented. This antenna is analyzed by using substrate with permittivity 4.3 and thickness 1mm. As the measured impedance bandwidth of proposed antenna is $118%(S_{11}{\leq}-10dB)$, its bandwidth is much broader than that of conventional annular ring slot antenna.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.9
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• pp.384-391
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• 2003

The wideband annular ring slot antenna with concentric radiating structure and low impedance feedline has been presented. This antenna has been analyzed in compensation for FR-4 substrate with relative permittivity 4.3 and thickness 1 mm. As the measured 10 dB impedance bandwidth of the proposed antenna is 127.2%(2.17∼9.76 GHz), its bandwidth is much broader than maximum 82% bandwidth of a conventional annular ring slot antenna. Experimental results from 2 to 10 GHz are shown to be in good agreement with the simulation. And this antenna has a high gain above 4 dBi from 2 GHz to 10 GHz as well as a 24% size reduction and 42% area reduction than a circular slot antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.3
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• pp.370-377
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• 2001

This paper proposed an eccentric annular ring microstrip antenna which has an asymmetric slot and a tuning stub for improving bandwidth and size of the circular microstrip patch antenna. The field characteristics of the eccentric annular ring microstrip antenna have been calculated by using the method of FDTD (finite difference time domain). The calculated results showed good agreement with the measured results. As a result of measurement, the antenna size and the bandwidth has been improved to that of 12.2 % and 4.8 % respectively, comparing to circular microstrip patch antenna.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.1
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• pp.78-84
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• 2008

In this paper, the reconfigurable annular ring slot antenna with circular polarization diversity is proposed for SDMB(Satellite Digital Multimedia Broadcasting) system. The proposed antenna consists of a ring slot with four tuning stubs. Four PIN diodes are attached to switch circular polarization diversity. By switching the diodes ON or OFF, the proposed antenna can be operated either RHCP mode or LHCP mode. The experimental result shows that the proposed antenna has an impedance bandwidth(VSWR${\leq}$2) of 570MHz(2.47-3.04GHz) at LHCP mode, an impedance bandwidth (VSWR${\leq}$2) of 560MHz(2.45-3.01GHz) at RHCP mode, a maximum gai of 3.1dBi at RHCP mode, 4.76dBi at LHCP mode. The 3dB CP bandwidth of about 100MHz at both RHCP and LHCP mode is achieved at the center frequency 2.63GHz. The proposed antenna is suitable for application such as mobile satellite communications, WLAN(Wireless Local Area Networks), and broadband wireless communication systems.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.302-305
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• 2002

본 논문에서는 기존의 원형 링 마이크로스트립 슬롯 안테나에 십자슬롯과 truncated를 통하여 원형편파를 구현할 수 있는 새로운 안테나 구조를 제안하였다. 금전구조는 입력단 설계가 간단하고 정함이 쉬운 전자파 결합방식을 사용하였고, Ansoft HFSS V8.0으로 최적화 한 후 제작 및 측정하였다. 제안된 안테나는 GPS(1.55MHz)대역에서 원형편파(RHCP, LHCP)특성을 만족하고, 각각의 안테나 구조에서 7.74%의 임피던스 대역폭(VSWR$\leq$2)을 갖고 안테나의 방사소자를 소형화하였다. 이는 기존의 월평 링 마이크로스트립 슬롯 안테나의 임피던스 대역폭 및 편파특성을 획기적으로 개선한 것이다.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.121-126
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• 2015

This paper proposes a novel reconfigurable microstrip antenna based on alternating a perturbation structure to achieve circular polarization diversity. The proposed antenna consists of an annular ring microstrip radiator for simultaneously loading stub and slot perturbations which support right- and left-handed circular polarization senses and two PIN diodes for choosing the operating polarization sense. By controlling the states of two PIN diodes between perturbing slot and stub at one diagonal corner of the radiator, reconfigurable circular polarization senses of the proposed antenna are successfully obtained and alternated. The proposed antenna has been theoretically analyzed and experimentally demonstrated at 2.4 GHz of S-band for satellite communication system. The simulation and measurement results of the proposed antenna show in good agreement with the reflection coefficients, axial-ratios, realized antenna gains, and radiation patterns.