• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.473-482
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• 1998

In this paper, characteristics of the wide band microstrip antennas with parasistic element are analyzed by the Finite Difference Time Domain(FDTD) method, and antenna parameters are optimized to get maximum bandwidth, retern loss, input impedance, and radiation pattern are calculated by Founier transforming the time domain results. The characteristics of the antenna are varied and the bandwidth of the antenna is broaded as a length and a width of the driven element, a gap of the driven element and the parasitic element, a width and a length of parasitic element. So the different patchs are resonating at different frequencies and this multipule resonance increase the bandwidth. The Results of the calculation and measurement, the size of the antenna with parasitic element is about a twice larger than a microstrip antenna, but bandwidth is four times better than a microstrip antenna. And these results were in relatively good accordance with the measured values.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.630-632
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• 2016

In this paper, we propose a modified rhombus slot UWB(Ultra Wide Band) antenna with fork-shaped feeding structure. The proposed modified rhombus slot structure is eliminated upper and lower part of the basic rhombus slot shape to get ultra-wideband characteristics for UWB communication. Also, feeding structure is used to fork-shaped structure to get ultra-wideband characteristics. The antenna is designed on an FR-4 substrate of which the dielectric constant is 4.4, and its overall size is $34mm(W1){\times}34mm(L1){\times}1mm(t)$, and its slot antenna size is $30mm(W2){\times}16.75mm(L3+L4)$. After the optimized process, the proposed antenna is fabricated and measured. Measured result. fabricated antenna satisfied -10 dB impedance bandwidth in UWB frequency band (3.1 ~ 10.6 GHz ). And measured results of gain and radiation patterns characteristics displayed determined for operating bands.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.6
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• pp.52-58
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• 2008

In this paper, electrically small square loop antenna with SRR (Split Ring Resonator) cover structure is built and tested. The proposed antenna has very small size, ka = 0.34 by Chu limit. The experimental result shows that the resonant frequency and impedance bandwidth($VSWR{\leq}2$) are 906MHz and 5.8MHz (901.7 - 907.5MHz), respectively. The proposed antenna is matched and designed by equivalent circuit model. The proposed antenna is fabricated simple structure without additional matching network and printed on a Teflon substrate without ground plane. Therefore, it has advantages of low cost, small size, and light weight and will be applied to wireless communication systems where small antennas are required.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.143-152
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• 2001

A method for miniaturization of microstrip patch antenna without degrading its radiation characteristics is investigated in this paper. It involves perforating the patch to form a microstrip square-ring antenna, and it's BW enhancement is investigated numerically and experimentally. A ring geometry introduces additional parameters to the antenna, and those are used to control impedances, resonance frequencies, and bandwidths. For a single square ring antenna, an increase of the size of perforation increases its input impedance, decreases the resonance frequency, and bandwidths. But it affects little on directivity of the antenna. To match the antenna to a transmission line and also enhance its bandwidth, the ring is stacked by a square patch or another square ring. Also numerically simulated results by the IE3D, and experimental data are compared for proof.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.1 s.116
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• pp.24-30
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• 2007

A windmill-shaped loop antenna is designed for polarization diversity. Its circumference is almost 10 times that of a conventional small loop antenna whose circumference is less than ${\lambda}/10$ but its the radiation pattern is omni-directional. An identical parasitic element is placed over the radiator to match the antenna input impedance. An equivalent transmission line and RLC circuit models are shown to fully describe for the windmill-shaped loop antenna. The proposed antenna has a bandwidth of 6 % with input VSWR less than 2:1 and a polarization purity of 15 dB at 2.6 GHz, and the gain of 1.5 dBi. The simulated and measured results show fairly good agreement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.5 s.120
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• pp.563-568
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• 2007

In this paper, the proposed package antenna, which is meander line structure with short pin, is miniaturized to realize RF-SoP at 900 MHz RFID band. The RFID BGA(Ball Grid Array) chip is put in a cavity of LTCC Layers. The coupling and cross talk, which are happen between BGA chip and proposed package antenna, are reduced by faraday cage, which consists of ground and via fences, is realized to enhance the isolation between BGA chip and antenna. The proposed antenna structure is focused on the package level antenna realization at low frequency band. The novel proposed package antenna size is $13mm{\times}9mm{\times}3.51mm$. The measured resonance frequency is 0.893 GHz. The impedance bandwidth is 9 MHz. The maximum gain of radiation pattern is -2.36 dBi.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.268-275
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• 2014

In this paper, a dual-band circular ring monopole antenna with stub and ground slot for WLAN(Wireless Local Area Networks)/WiMAX(World interoperability for Microwave Access) applications. The proposed antenna is based on a planar monopole design, and composed of one circular ring of radiating patch, cross strip in circular ring, modified feed line, and two rectangular slot in the ground plane for triple-band operation. To obtain the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and found the parameters that greatly effect antenna characteristics. Using the obtained parameters, the antenna is fabricated. The numerical and experiment results demonstrated that the proposed antenna satisfied the -10 dB impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. And characteristics of gain and radiation patterns are determined for WLAN/WiMAX application.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.17-23
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• 2021

In the present study, a more compact dual-band slot antenna is newly proposed for Wi-Fi application. The proposed antenna is composed of rectangular two stepped slot with open end which can generate standing wave resonance at dual frequency bands and L-type microstrip feed line. The measured impedance bandwidths are 50 MHz(2.412 ~ 2.470 GHz) at low frequency band and 452 MHz(5.451 ~ 5.903 GHz) at high frequency band respectiviely. Furthermore its size of 14 × 21 mm² is reduced by 30% compared to the size of 20 × 21 mm² of a conventional similar compact slot antenna. It has the omni-directional radiation pattern characteristics of a typical dipole antenna on the H-Plane, so it is suitable for commercial wireless network applications such as Wi-Fi.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.33-40
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• 2019

In this paper, a microstrip-fed triple-band antenna for WLAN system with microstrip lines was designed, fabricated and measured. The proposed antenna is composed of two strip lines and slit in the ground plane and then designed in order to get triple band characteristics. We carried out simulation on $L_3$, $L_{10}$, and slit parameters, and adjusted the parameters of the proposed antenna to satisfy the required frequency band and bandwidth. The proposed antenna is made of $32.0{\times}44.0{\times}1.0mm$ and is fabricated on the permittivity 4.4 FR-4 substrate. The experiment results shows that the proposed antenna obtained the -10 dB impedance bandwidth 120 MHz (890 MHz~1.01 MHz), 440 MHz (2.35~2.79 GHz), and 1,280 MHz (5.07~6.35 GHz) covering the triple WLAN bands. Also, the measured gain and radiation patterns characteristics of the proposed antenna are presented at required frequency band, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.127-134
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• 2022

A modified folded monopole slot antenna for 3G WCDMA (1.91 ~ 2.17 GHz), 4G LTE (2.17 ~ 2.67 GHz), 3.5 GHz 5G (3.42 ~ 3.7 GHz) and Wi-Fi dual band (2.4 ~ 2.484 GHz / 5.15 ~ 5.825 GHz) was proposed for the first time. The proposed antenna is designed and fabricated on a FR-4 substrate with dielectric constant 4.3, thickness of 1.6 mm, and size of 35 × 60 mm². The measured impedance bandwidth of the proposed antenna is 2910 MHz(1.84 ~ 4.75 GHz) and 930 MHz(5.11 ~ 6.04 GHz), antenna gain in each frequency band is from 1.811 to 3.450 dBi. In particular, it was possible to obtain a commercially suitable omni-directional radiation pattern in all frequency bands of interest.