• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.807-811
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• 2001

In this paper we proposed a dual-frequency circular sector microstrip antenna with orthogonal polarized modes and high isolation between the two feeding ports. And then we designed a transceiver operating at 5.6 GHz for transmitting and at 5.5 GHz for receiving. The good isolation provided by the proposed antenna is used as the basis for the transmit-receive filtering of transceiver. The operating frequencies and polarization characteristics of the proposed antenna is calculated by using a cavity model. The 5-parameters and radiation patterns of the antenna are measured. A power amplifier and a low noise amplifier are designed and integrated with antenna to make a transceiver, which has about 13dB transmitting gain and about 8㏈ receiving gain.

• Smart Media Journal
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• v.4 no.4
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• pp.64-69
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• 2015

In this paper, we have proposed a tapered slot antenna for UWB communication system. The tapered slot antenna has directional radiation and broad bandwidth. Proposed tapered slot antenna is designed using Ansys Inc. HFSS and its VSWR, return los, and radiation pattern is analyzed. Operating band of the antenna were satisfied -10 dB S11 and $VSWR{\leq}2$ in 2.7 ~ 4.8 GHz band. The radiation pattern of the antenna is showed in E-plane (YZ plane) and the H-plane (XZ plane) and the highest gain of 7.3 dBi is seen at 4.5 GHz. Therefore, proposed tapered slot antenna has wide bandwidth characteristic and directional for location awareness.

• Journal of IKEEE
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• v.17 no.3
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• pp.385-392
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• 2013

In this paper, microstrip antenna to enhance the isolation between transmitting port and receiving port under the proximity objects is proposed, and applied to the Doppler radar sensor working at 5.8GHz ISM band which detects vital signals of a human body. Two 3dB quadrature hybrids are placed around radiation patch to form a balanced structure between transmitting port and receiving port, such that it consistently provides enhanced Tx/Rx isolation and excellent return loss over nearby objects. It is theoretically analyzed and simulated to verify the validity of the proposed application. The fabricated antenna that is 2mm away from the human body, has more than 16 dB return loss and at least 30dB isolation over ISM frequency band of 5.8GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.145-151
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• 2008

In this paper, a dual band microstrip antenna with similar radiation pattern for the satellite internet service is proposed. The proposed antenna has two Y-shaped slots on the microstrip patch that is fabricated on RO4003 substrate with a dielectric constant of 3.38 and a thickness of 0.508 mm, and operates in the 2 GHz and 5 GHz bands. The size of the antenna is $50\times47.5\times6.5\;mm^3$, and fed by coaxial cable. The measured bandwidths of the antenna are 2.398$\sim$2.507 GHz and 5.458$\sim$5.972 GHz for VSWR<2. The measured gains are 8.92 dBi and 7.74 dBi, respectively, for the lower and upper bands.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.2 s.344
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• pp.81-87
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• 2006

A small size broadband microstrip patch antenna with small ground plane has been fabricated using MEMS. Multiple layer substrates we used to realize small size and broadband characteristics. The microstrip patch is divided into 4 pieces and each patch is connected to each other using a metal microstrip line. The fabrication please process is simple and only one mask is needed. Two types of microtrip antennas are fabrication Type A is the microstrip antenna with metal lines and type B is the microstrip antenna without metal lines. The size of proposed microstip antenna is $8{\times}12{\times}2mm^3$ and the experimental results show that the antenna type A and type B have the bandwidth of 420MHz at 5.3 GHz and 480MHz at 5.66 GHz, respectively

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1633-1640
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• 2016

In this paper, we propose a open-ended rectangular microstirp patch antenna with fork-shaped feeding structure. This antenna extends the effective bandwidth by transforming single or multi resonant frequency and is designed planar monopole structure with microstrip line to satisfy the WLAN bands (2.4 - 2.484, 5.15 - 5.35, 5.25-5.825 GHz). The substrate is printed in 0.8 mm thickness on an FR-4 board. A commercial 3D simulation tool was used to analyze surface current and electromagnetic field distribution in order to analyze the operation mode and reconfiguration principle of antenna. According to the lengths of individual patches, simulated reflection loss was compared to obtain optimized values. When it was designed with the optimized values, it satisfied WLAN bands (2.380 - 2.710, 4.900 - 5.950 GHz), if the switch is off, and 2.4 WLAN band (2.380 - 2.710 GHz). From the fabricated and measured results, measured results of return loss, gain and radiation patterns characteristics displayed for operating bands.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.7
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• pp.987-994
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• 2013

In this paper, a dual-band open-ended circular ring moNopole antenna for WLAN(Wireless Local Area Networks) applications. The proposed antenna is based on a planar moNopole design, and composed of open-ended one circular ring of radiating patches 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 proposed antenna is fabricated. The fabricated antenna is measured at the operating frequencies(2.4-2.484 GHz, 5.15-5.825 GHz), and the return loss coefficient, gain, and radiation patterns are determined.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.739-745
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• 2009

This paper presents a design for trapezoidal planar UWB(Ultra Wide-band) antenna using symmetry meander line to realize broad bandwidth at low frequency region. The size of proposed design antenna is $15.5{\times}21{\times}1.6mm^3$ and dielectric substrate considered in design has 4.4 of relative permittivity. The calculated bandwidth is from 1.31 GHz to 10.83 GHz and the measured return loss is 1.5 GHz to 10.6 GHz at -10 dB below, and satisfies with the UWB antenna's bandwidth. The simulated and measured radiation patterns show fine agreement with each other at each frequency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3623-3627
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• 2012

The modern society has become full-fledged entry into the information age since spread of Internet. In the information age, internet was developed from the wired access to the wireless Internet access. When a surge in demand for wireless Internet access, efficiency and performance of 2.4GHz band which leads to saturation of the communication was significantly fall. Accordingly, the communication of the 5GHz band came to be interested. In this paper, we studied the design and fabrication of u-slot microstrip patch antenna to be used in wireless communication systems operating at around 5GHz band. To obtain antenna parameters such as patch size, inter patch space, antenna was simulated by HFSS(High Frequency Structure Simulator). From these parameters, u-slot microstrip patch antenna is fabricated using FR-4 substrate of dielectric constant 4.4. The characteristics of fabricated antenna were analyzed by network analyzer.

• Journal of IKEEE
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• v.26 no.1
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• pp.137-140
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• 2022

In this paper, we proposed a new W-band monopulse tracking system based on reflectarray antenna structure. The proposed reflectarray antenna monopulse tracking system consists of four feed horn antennas and a planar reflector using a microstrip reflectarray. The four feed horn antennas have a gain of 10 dBi and a half-power beam-width of 56 degrees symmetrically in the E/H plane. It was confirmed that the reflectarray antenna using one feed horn antenna has a size of 41.8 × 41.8 mm², a gain of 26.8 dBi, and a half-power beam-width of about 5.6 degrees. The reflectarray monopulse tracking system using 4 feeding horn antennas is well matched from 75 GHz to 90 GHz, and the isolation is secured by more than 10 dB. Finally, the proposed system shows the tracking range of 5.98 degrees and the tracking error range was 0.02 degrees.