• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.5 s.96
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• pp.501-510
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• 2005

In this paper, the miniaturized linear and circular polarization microstrip antennas are designed and fabricated at the resonant frequency of 1.575 GHz. To miniaturize the microstrip patch antenna(MPA), the 'L' type plates are attached under the rectangular microstrip patch. In case of the linear polarization, the size of the microstrip antenna attached the 14 plates is reduced to $67.9\%(47mm{\times}47mm)$ compared with general $MPA(83mm{\times}83mm)$. The return loss and -10 dB bandwidth are -34.4 dB and 49 $MHz(3.1\%)$. And the radiation pattern is broad through the size reduction of the patch. Also in case of the circular polarization, the size of the microstrip antenna with 13 plates is reduced to $54.6\%(53mm{\times}54mm)$ compared with the general $MPA(76mm{\times}83mm)$. The axial ratio is 1.37dB at 1.575 GHz, the 2 dB axial ratio bandwidth is 14 $MHz(0.8\%)$. As that result, we could confirm that 3-dimensional structure with attached 'L' shaped plate is proper form for the miniaturization of linear and circular polarization microstrip antenna.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2268-2272
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• 2010

This letter presents that a rectenna can utilize more stable wireless power by using a new design dual band/dual polarization microstrip patch antenna and 2 stage voltage multiplier at 2.4 GHz band and 3.1 GHz band. The proposed antenna is a new microstrip patch antenna design to make impedance matching possible by using slotted capacitive coupling between the patch and $50\Omega$ feed line on a ground plane. Its advantage is that the size of the rectenna can be reduced by using $50\Omega$ feed line on the ground plane, which can be used efficiently. The dual band/dual polarization microstrip patch antenna shows circular polarization at 2.4 GHz band and linear polarization at 3.1 GHz band. Under -10 dB return loss, The dual band/dual polarization microstrip patch antenna obtains 340 MHz bandwidth as 2.23~2.57 GHz and 375 MHz bandwidth as 2.95~3.325 GHz. Also, 2 Stage Voltage multiplier is possible to operate at 2.4 GHz band and 3.1 GHz band. The designed retenna can usually obtain wireless power at both 3.1 GHz band, and 2.4 GHz band applications such as Wi-Fi, Bluetooth, Wireless LAN, etc. So more stable wireless power can be utilized at the same time.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.9
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• pp.679-684
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• 2017

This paper presents an UHF(Ultra High Frequency) band small cavity structured RFID(Radio Frequency Identification) tag antenna with a long reading range, designed to apply on metal cart or pallet for auto-parts logistics. The size of tag antennas is $140{\times}60{\times}10mm^3$, attached on a exporting metal cart, and it can give the information of inventory and logistics of carts. By collecting the exported carts and increasing the recovery rate of missing carts or pallets, the paid import tax can be refunded when the carts are returned back to the manufacture. The tag antenna was equipped with a cover to prevent damage, and the dielectric constant of the cover is considered for the simulation. The reading range of the tag antenna is 12 m using LP(Linear Polarization), 10 m with CP(Circular Polarization) reader antennas. This 920 MHz UHF RFID cavity tag ensures the long reading distance of the antenna regardless of the material of the object where it is attached.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.823-830
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• 2010

This paper deals with a coaxial-to-waveguide transition generating circularly polarized wave to be connected with horn antennas. By combining vertical coaxial fed structure, back-short and the polarization twisting structure, the circular polarization is successfully generated in the waveguide. The designed and implemented transition shows that the present structure can significantly reduce the size of the antenna part at X-band.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2001.02a
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• pp.142-144
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• 2001

We designed superconducting four-element patch array antenna which has single-feed circularly polarization and a resonance frequency of 11.85 GHz for DBS receiving system. Antennas have been fabricated from both gold conductor and $YBa_{2}$$Cu_{3}$$O_{7-x}$(YBCO) superconductor (thin films) for comparison. Simulated and measured results, and analysis on resonant frequency(fr), return loss, and bandwidth are presented.

• Journal of electromagnetic engineering and science
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• v.13 no.3
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• pp.165-172
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• 2013

This paper describes a design for a spiral antenna with a conical wall to obtain the high gain. The gain and the axial ratio of the spiral antenna were improved by a new design that included a conical wall and an optimized Archimedean slit on the ground plane in a conventional antenna with a circular cavity wall and a 4.5-turn slit. A gain improvement of 9.5 dBi higher and a good axial ratio of 1.9 dB lower were measured by the added conical wall and the newly designed slit from the current distribution control on the ground plane, respectively. The measured return loss, gain and axial ratio of the proposed antenna showed a good agreement with the simulated results. The proposed antenna will be applied to a non-linear junction detector system.

• Journal of electromagnetic engineering and science
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• v.5 no.1
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• pp.31-35
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• 2005

This paper presents low form factor dual polarized antenna incorporating low profile annular ring patch antenna having 90$^{\circ}$ phase delay element for circular polarization(CP) and a reactive-loaded monopole linear polarized(LP) antenna. Both types of receiving antennas operate in the same frequency region from 2.320 GHz to 2.345 GHz, while different polarizations are used to take advantage of polarization diversity. The proposed CP antenna has good broadside radiation patterns, while the LP antenna reveals monopole-like radiation patterns. The gains of the antennas are measured to be 1.93 dBi and 2.24 dBi for CP and LP, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.1-9
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• 2014

In this paper, a reconfigurable polarization patch antenna that uses a Y-shaped feed is proposed. The proposed antenna consists of a square patch, a Y-shaped feeding structure, a PIN diode, and a bias circuit for diode operation. The structural symmetry/asymmetry of the feeding structure is determined by the on/off operation of the PIN diode that inserted into the side of one of the lines of the Y-shaped feeding structure. For the proposed reconfigurable antenna, the two microstrip lines of the feeding structure have the same length when the PIN diode operates in the on state, and the antenna exhibits linear polarization(LP). On the other hand, when the PIN diode operates in the off state, the length of one side line of the feeding structure is relatively shorter than that of the other line. Therefore, the antenna exhibits circular polarization(CP). From the measurement results, it is found that the proposed antenna exhibits good impedance matching and axial ratio. In addition, polarization switching can be easily achieved in the same operating band.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.463-468
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• 2023

In this paper, we proposed reconfigurable dual polarization patch array antenna that can select two polarizations(Vertical, RHCP) using defected ground structure and Pin diode. The proposed antenna was designed arranging a circular polarization patch antenna implemented with a square microstrip patch and two slots 3x3 at 25.8mm placed, a half-wavelength of 5.8 GHz. Conect the pin diode and the capacitor to the slot diagonally placed on the ground of each antennas, and select polarization using the open/short operating according to the application of DC voltage to the pin diode. As a result of the design, the gain of the antenna is 11.7 dBi at vertical polarization and 11.6 dBic at RHCP. The axial ratio is 20.3 dB at 1.8 dB vertical polarization at RHCP. Mutual Coupling is Maximum to -20.8 dB for vertical polarization and Maximum to -30.1 dB for RHCP.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.367-370
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• 2005

In this paper, we made a Singly Fed patch which is the fittest at the feeding part. And we found out return loss and radiation pattern about dielectric rod array antenna which has six's passive element to shape FTEP(Flat-topped element pattern) after we analyzed the characters of singly dielectric rod antenna. We show the conclusion that has the optimum return loss and more flat radiation pattern.