• Journal of electromagnetic engineering and science
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• v.13 no.2
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• pp.63-72
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• 2013

The ultra-wideband (UWB) spectrum available for commercial applications has offered us an opportunity to achieve high-speed wireless communications and high-accuracy location applications. As one of key research areas in UWB technology, a lot of innovative broadband and miniaturization techniques for UWB antennas have been greatly invented and developed for years. This paper reviews the development of UWB antenna design in the past decade. Starting with a brief introduction of the specific requirements and promising applications of UWB systems, the unique design challenges of UWB antennas are highlighted. Next, the important milestones of UWB antenna designs are briefed. After that, a variety of planar UWB antennas invented for broadband operation, miniaturization, and multiple functions are introduced. Last, the comments on the development of UWB antennas in future are shared.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.552-559
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• 2011

In this paper, the frequency reconfigurable antenna is proposed and designed. The proposed antenna is designed using the vertically stacked dipole structures and have the operating band for Cellular, PCS/WCDMA/Wibro/WiFi and WiMAX. The operating frequency band is selected by three pair of PIN diodes using the voltage difference between each dipole antenna and feeding transmission lines. The proposed antenna meets the required operating bandwidth and the maximum gain for each frequency band are measured as 6.3 dBi, 5.4 dBi and 5.8 dBi, respectively. The proposed antenna in this paper can be applied for the future mobile small base station or repeater antenna because this antenna can provide the small size and high gain features.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1659-1665
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• 2019

In this paper, a novel design of a compact printed monopole antenna for wireless local area network (WLAN) applications is investigated. The radiator with a patch of different line width and step-shaped ground planes is used to reduce the antenna size. The size of the antenna is 16 × 17 × 1 ㎣ and is fabricated with a photolithography technique. The simulated and measured results agree well. The resonant frequency of the investigated antenna is about 5.2 GHz and can cover an impedance bandwidth of 1 GHz for the measurement result. In addition, we presented the measured radiation pattern, presented the gain and efficiency measured in the required WLAN 5 GHz frequency band (5.15-5.825 GHz), and confirmed that it can be used as a 5 GHz band WLAN antenna. The investigated antenna has a small size, light weight, low cost, omni-directional radiation pattern, high gain, and high efficiency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.983-993
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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 faces 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 limited radiation of the small-sized antenna.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.6 s.324
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• pp.93-99
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• 2004

According to rapid increment of demand for wireless Local Area Network (LAN), the HyperLAN of 5.1-533GHz and 5.725-5.825GHz is newly allocated for wireless LAM in many regions over the world. Also, because most of mobile communication equipments are small, the size of antenna is important factor of effective design. In this paper, the compacted and wide bandwidth antenna is designed for wireless LAN at 5GHz band. Although the structure of U-shaped slot antenna is simple, It has large bandwidth of $10-40\%$. Also, the U-slot antenna has good radiation pattern. However, in general, the size of U-slot antenna is large. Therefore, it is difficult to apply to wireless equipment such as PDA and Notebook. This proposed antenna has a wide bandwidth by U-shaped slot in rectangular patch and is compacted by using two layered dielectric substrates and foam. For the design of U-slot antenna, the Finite Difference Time Domain method is applied. Also, the method of MPI parallel program is used for the enhancement of the analyzing speed of the FDTD method.

• Journal of the Korea Convergence Society
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• v.6 no.1
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• pp.109-114
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• 2015

A circularly polarized small UHF RFID reader antenna is presented. The antenna is composed of four elements and printed on the plastic substrate(${\varepsilon}_r=2.2$, t=5mm). Each element is fed by a probe which is sequentially connected to the feed line. The feed line is manufactured on the FR-4 substrate(t=1.0mm, ${\varepsilon}_r=4.7$). The simulation results shows that the antenna can be achieved a return loss of 12dB, gain of 3.46dBic over the UHF band of 902-928MHz. According to our simulation results, two prototype antennas are manufactured and measured. The obtained antennas operate in UHF RFID bands and can be adapted for various portable applications. In addition, a parametric study is conducted to facilitate the design and optimization processes.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1239-1245
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• 2009

Currently, so many approaching methods are being developed to optimize the antenna size. In this paper, We fabricated Inverted-F type antenna attaching lumped components to solve the limitation of antenna size. Through experiments, a basic Inverted-F type antenna was fabricated and satisfied the adequate radiation pattern. After this, we researched the effect of antenna varied by matching circuit consist of chip type resistor, inductor, and capacitor. Using that elements, the antenna was matched at aim frequency. The proposed antenna's size is $7\;{\times}\;24\;mm$ that is very small size against the resonance frequence. Measuring the developed antenna, Its return loss was -18dB. Thus, this antenna can be used for Z-wave systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11A
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• pp.912-920
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• 2003

This paper is about the design of a small wide-band slot loop antenna, which consists of dual offset-fed and rectangular loop within the slot on a substrate. The proposed antenna is a novel structure generating a multi-resonances due to three geometrical resonance structures. The impedance matching of this antenna can be accomplished by changing the offset position of dual-fed at resonance frequencies. In this experiment, the slot of a fabricated antenna has a center frequency of 6.755㎓, 12.5mm${\times}$50mm in size and the rectangular loop has 10.5mm${\times}$27.5mm in size. The measured result is fractional bandwidth 63.21% with VSWR 2:1, which is agreed with the simulated result within 5% of error, and the maximum antenna gain is 7.42㏈i.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.288-297
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• 2007

The novel internal monopole chip antenna of penta-band operation for GSM850/GSM900/DCS/USPCS/WCDMA bands for mobile phones is proposed. This antenna occupies a small volume $8\times3.2\times20mm^3$ and is suitable to be embedded in a mobile phone as an internal antenna. The minimization of the proposed antenna was realized by using spiral line structure and meander line structure on FR-4 of dielectric$(\varepsilon_r=4.4)$. The designed antenna has the wide-band operation in the upper band by overlapping high order resonances. The measured bandwidth of this antenna (VSWR>3) is 150MHz$(1,030\sim1,180\;MHz)$ in the lower band operation and 650 MHz$(1,760\sim2,410\;MHz)$ in higher band operation. The measured radiation efficiency within bandwidth(VSWR 3:1) is over 50 %. The antenna has been designed by a commercial software HFSS.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.2
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• pp.42-49
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• 2014

A broadband antenna using a main and a sub antenna for the mobile communication terminal such as mobile phone and ITS terminal is designed. Two antennas are based on the hybrid antenna that is operating both a monopole and a IFA(Inverted F Antenna). It's applied the transmission line to connect both antennas. Sub antenna located in small space of the terminal allows space usability for the terminal design. Antenna for the hexa-frequency band of LTE700, CDMA, GSM, DCS, PCS and WCDMA is designed and implemented on the bare PC board that is same size of the mobile phone. This antenna was measured 3 : 1 VSWR over the whole design band. And average gains and efficiencies were-3.78 ~ -2.62dBi and 41.9 ~ 54.73% for LTE700/CDMA/GSM frequency band, -3.75 ~ -1.84dBi and 42.19 ~ 65.46% for DCS/PCS/WCDMA frequency band.