• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.215-218
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• 2002

In this paper, a dual-frequency printed slot antenna loaded with an open-ring conducting strip and capacitively fed by a coplanar waveguide(CPW) is designed. The designed antenna has a bandwidth of 240㎒(1690㎒-1930㎒) at PCS frequency band and of 160㎒(2380㎒-2540㎒) at WLAN frequency band. In both frequency ranges, pattern and gain requirements are satisfied. The commercial software, IE3D, was used to design slot antenna. The predicted characteristics along with measured data are presented for verification purpose.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1338-1343
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• 2018

MIMO(Multiple Input Multiple Output) slot antenna that operates on the dual WiFi band(2.401~2.495GHz, 5.18~5.825GHz), in this paper, was studied. The basic theory for the slot design is based on the coupling between adjacent slot, and slots are fed by the each microstrip lines. Two slot antennas for the MIMO operation are located on the left and the right side of top of the metal notebook, and grounds between a notebook and two microstrip feeding lines are connected. Measurement of return loss showed under -6dB on entire design band, and isolation was below than -30dB. Radiation efficiency, average gain and peak gain for the left and the right slot were measured in the anechoic chamber, and showed good performances as 57.25%, -2.42dBi, 5.64dBi and 55.35%, -2.61dBi, 6.42dBi for the 2.4GHz band and 55.89%, -2.58dBi, 7.3dBi and 53.79%, -2.8dBi, 7.54dBi for the 5GHz band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.9
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• pp.1070-1076
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• 2007

In this paper, we study the characteristics of dual band microstrip antenna with the wedge-shaped radiation patch added the slot using air substrate. Wedge-shaped patch antenna with air substrate is avoided the large probe reactance associated with a thick substrate owing to the use of short probe and good impedance matching over a wide frequency range can be obtained. Slot on the antenna radiator varies the reactance component according to the employed frequency and affect the resonance freaqency of the antenna, therefore the antenna can resonate at the dual band(cellular and PCS band). The slot length and position have an effect on the bandwidth and input impedance of the antenna are optimized by simulation. From the experiment results for the fabricated antenna, -10 dB of $S_{11}$ is content with the allocated bandwidth of Cellular and PCS system and - 15 dB of cross polarization level. From the results of this paper, it has been confirmed that the proposed antenna can be used as the base station antenna fur Cellular and PCS band.

• Journal of IKEEE
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• v.27 no.1
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• pp.109-115
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• 2023

In this paper, we design and implement an Ultra-Wide Band (UWB, 3.1~10.6 GHz) antenna with 5G mobile communication (3.42~3.70 GHz) and Wireless Local Area Network (WLAN, 5.15~5.825 GHz) bands rejection characteristics. The proposed antenna consists of a planar radiation patch with two slots. The upper slot contributes to reject 5G mobile communication band and the lower slot contributes to reject WLAN band. The Voltage Standing Wave Ratio (VSWR) values of the proposed antenna show good performances in whole UWB band except for rejection bands based on VSWR 2.0. The proposed UWB antenna was simulated using High Frequency Struture Simulator (HFSS) by Ansoft. The simulated antenna showed dual rejection bands of 3.31~3.92 GHz and 5.04~5.90 GHz in UWB band, and measured antenna showed dual rejection bands of 3.35~3.97 GHz and 5.06~5.97 GHz. The largest VSWR values measured at each rejection band are 13.60 at 3.64 GHz and 10.25 at 5.52 GHz. The measured maximum gain is 5.31 dBi at 10.00 GHz. The lowest gains for the measured antenna at rejection bands are -8.73 dBi at 3.70 GHz and -4.36 dBi at 5.56 GHz.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.27-34
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• 2012

In this paper, Coplanar waveguide(CPW)-fed slot loop antenna, which is applicable to the dual band(2.4GHz~2.4835GHz, 5.15GHz~5.825GHz) for the wireless LAN, is proposed. In order to miniaturize the proposed antenna, slot loop is bent by meandering. The resonant frequencies in the required dual band are adjusted by variation of the resonant length of slot loop as well as slot width. In particular, use of capacitive coupling CPW feed provides impedance matching without a seperate matching circuit, because the amount of electromagnetic coupling can be controlled by the offset between feed and radiator. As a result, it has been observed that the proposed antenna satisfies not only the required return loss(${\leq}10dB$) but also has high efficiency(${\geq}80%$) over the whole frequency band. In order to check the validity of the proposed antenna, some simulated results for return loss and radiation pattern are presented in comparison with the measured results.

• Journal of electromagnetic engineering and science
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• v.17 no.1
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• pp.44-49
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• 2017

A compact planar microstrip-fed ultra-wideband (UWB) antenna with a dual band-notched for UWB application is presented and analyzed. By inserting a U-shaped slot and inverted U-shaped slot into the pot-shaped radiator, two notched bands are achieved. By optimizing the width and length of the U-shaped slots and inverted U-shaped slot, a desired bandwidth of voltage standing wave ratio (VSWR) less than 2.0 can be achieved, ranging from UWB bands with notched dual bands. The proposed antenna is fabricated on an inexpensive FR-4 substrate with overall dimensions of $28.0mm{\times}39.5mm$. The measured results confirm that the proposed antenna covers from 1.775 to over 13.075 GHz with two rejection bands of around 3.325-3.925 GHz and 5.3125-6.025 GHz. In addition, the proposed antenna showed good radiation characteristics and gains in the UWB bands.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.37-44
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• 2020

In this paper, we proposed a compact printed monopole antenna with an inverted L-shaped slot for dual-band operations. Two operating frequency bands are achieved with the use of an inverted L-shaped slot etched on the radiating strip for bandwidth enhancement and a defected ground structure for return loss improvement in the higher frequency band. The measured results showthat the proposed antenna has impedance bandwidths (S₁₁< -10 dB) of 270 MHz (1.81-2.08 GHz) and 340 MHz (2.36-2.70 GHz), covering the required bandwidths for PCS (1850.5-1989.5 MHz), CDMA 2000 (1850-1990 MHz), TD-SCDMA (1880-2025 MHz) and 2.4 GHz WLAN (2400-2484 MHz). The measured return loss of the proposed antenna has a good value of approximately 27.2 dB at 2.4 GHz WLAN. The antenna's peak gains also have a high value of 1.92 dBi at 2 GHz and 2.12 dBi at 2.45 GHz. The proposed antenna shows omnidirectional radiation patterns over the entire frequency range of interest.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2265-2272
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• 2013

In this paper, a dual-band circular ring monopole antenna with stub and ground slot for is proposed WLAN(Wireless Local Area Networks) applications. The proposed antenna is based on a planar monopole design, and composed of one circular ring of radiating patches, and modified feed line, and rectangular slot in the ground plane for dual-band operation. To obtain the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and found the parameters that effect antenna characteristics. Using the obtained parameters, the antenna is fabricated, and the return loss coefficient, gain, and radiation patterns are determined for WLAN application.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.75-80
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• 2021

In this paper, a dual-band Koch Snowflake antenna is proposed for wireless communication systems. Fractal geometry, CPW-feed and stepped ground planes are used to improve the impedance bandwidth. By properly introducing a hexagonal split-ring slot to radiating element, a lower frequency band is generated. The proposed structure is fabricated and tested. Experiment results exhibit dual-band of 0.73-0.98 GHZ and 1.6-3.1 GHz which makes this antenna suitable candidate for GSM900, GSM1800, UTMS2100, Wi-Fi 2400 and LTE2600 bands. In addition, a good radiation pattern, a satisfactory peak gain and a radiation efficiency, which reaches 95%, are achieved.

• 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.