• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.10 no.5
• /
• pp.757-765
• /
• 1999

In this paper, L-Type aperture coupled circular polarization patch antenna for mobile communication(IMT-2000, 1.9375 GHz), which is capable of being mounted in mobile unit, was designed and fabricated. This antenna is expanded to the $2\times2$ circular polarization array antenna for satellite mobile communications which are using the L-band frequency. The results are as followings : Returnloss 18.56 dB, beamwidth $60^{\circ}$, gain 7 dBd, axial ratio 0.9 dB in the case of single element and returnloss 28.43 dB, beamwidth $38^{\circ}$, gain 9.8dBd, axial ratio 1.5 dB in the case of $2\times2$ array, respectively.

• Journal of information and communication convergence engineering
• /
• v.19 no.3
• /
• pp.131-135
• /
• 2021

The interference between closely placed co-coverage satellites was analyzed. In general, a satellite network may use different orthogonal polarizations and frequencies to increase the throughput of a satellite. However, when orthogonal linear polarization (horizontal polarization and vertical polarization) or orthogonal circular polarization (left-handed circular polarization and right-handed circular polarization) is used, the signal from one polarization sense to another may be coupled, resulting in cross-polarization interference. This signal-coupling arises due to the finite value of the cross-polarization discrimination of the earth station. In this study, field equations were used to analyze the interference between adjacent satellites using co-frequency. The level of interference was compared to that when two adjacent satellites used the same polarization. The simulation results show that the interference mainly depends on the off-axis co-polar pattern and the cross-polar pattern of the earth station antenna.

• Journal of the Semiconductor & Display Technology
• /
• v.17 no.2
• /
• pp.20-25
• /
• 2018

In this paper, we have designed circularly polarized array antenna for 5.8GHz microwave wireless power transmission. To obtain high antenna gain, we studied a single patch antenna, a $2{\times}1$ array antenna, a $2{\times}2$ array antenna, a $2{\times}4$ array antenna, and a $4{\times}4$ array antenna. Commonly, characteristics of each antenna have a frequency of 5.8 GHz and Right Hand Circular Polarization(RHCP) of circular polarization. Also, the results were obtained with the design to each antenna that the return loss was less than -10dB and the axial ratio was less than 3dB. The gain of the antennas was 6.08dBi for a single patch antenna, 9.69dBi for a $2{\times}1$ array antenna, 12.99dBi for a $2{\times}2$ array antenna, 15.72dBi for a $2{\times}4$ array antenna and 18.39dBi for a $4{\times}4$ array antenna. When the elements of the array antenna were increased, it was confirmed that it increased by about 3dBi.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.25 no.2
• /
• pp.164-171
• /
• 2014

Transmit(Tx)/Receive(Rx) dual band operation microstrip array for X-band satellite communications are designed, fabricated, and measured in this paper. The microstrip array antenna has Right Handed Circular Polarization(RHCP) for Tx band and Left Hand Circular Polarization(LHCP) for Rx band. Two stacked patches are used for wideband characteristics and corner-truncated square patches are adopted for a circular polarization. To enhance bandwidth characteristics of a circular polarization, $2{\times}2$ sequential rotation array are applied. From the measured result, $8{\times}12$ microstrip array antennas have a good agreement with those of the simulation. Therefore the array antennas are applicable to military satellite communication antennas.

• Proceedings of the KIEE Conference
• /
• 2004.07c
• /
• pp.2052-2054
• /
• 2004

The TX/RX broadband L-type circular polarization antenna using LTCC at K/Ka band has been presented. This antenna has been analyzed in compensation for LTCC with relative permittivity 5.2 and could have been integrated with RF component. As the measured 10dB impedance circular polarization bandwidth of the proposed antenna is 7%(20.8GHz${\sim}$22.2GHz) at the K band and 2.3%(30.9GHz to 31.6GHz) at the Ka band. Also the gain of the antenna is -0.7${\sim}$3.05dBi at the K band and -2.8${\sim}$1dBi at the Ka band. The purpose of the research is to design an efficient antenna structure for satellite communication at K/Ka band. the antenna should be used for both TX and RX frequency bands. The antenna will be mounted on LTCC(Low Temperature Co-fired Ceramic) so that it can be integrated with other RF circuits. This research is important because of the following reasons. 1) The frequency ranges of satellite communication tends to move up to higher frequency such as Ka band or milimeter wave band. 2) Design of antenna for smaller size, lighter weight and less loss is preferred by most RF engineers. 3) Antennas on LTCC enables to integrate the antenna with other RF circuits, and thus, one can reduce the size and loss of the RF system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.12
• /
• pp.1316-1324
• /
• 2009

In this paper, cross-aperture coupled microstrip circular polarization antenna is proposed for 5.8 GHz WLAN(Wireless Local Area Network). A single antenna consists of square patch and slots are located in series feed line with $\lambda_g$/4 phase different which make current direction maximum and minimum repeatedly to generate RHCP(Right Handed Circularly Polarization). We are proposed new structure that removed the section which intersected at a right angle and were composed to four separated slots. The proposed cross slots reduce back lobe of radiation pattern and improve antenna gain. Impedance bandwidth of the manufactured $2\times2$ array antenna is from 5.67 to 5.95 GHz and the maximum radiation gain is 10.59 dBi.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.11
• /
• pp.3137-3143
• /
• 2009

In this paper, a single arm spiral antenna has been investigated about the characteristics of polarization and tilt beam. If a circumference length of spiral is bigger than a wavelength, it have a characteristic of varying maximum radiation beam direction. In addition, circular polarizations (RHCP, LHCP) can be variable by the feeding points (inner, outer). Also maximum beam directions tilt in different direction according to the circular polarizations, LHCP and RHCP. These characteristics of single arm spiral antenna are able to apply in the beam forming, diversity, MIMO application which has dual polarization using an antenna element.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.05a
• /
• pp.234-237
• /
• 2002

A microstrip patch antenna with circular polarization based on the Sierpinski fractal is composed of 3 equilaterial triangular Polarization by sequentially rotation techniques. The characteristics of a $1\times3$ antenna array from Sierpinski geometry an investigated, i.e. port isolation and AR(axial Ratio).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.5 s.96
• /
• pp.526-533
• /
• 2005

In this paper, the miniaturized the linear polarization and the circular polarization microstrip antennas, which are the two ends in the resonance length direction or all the four-ends were folded are designed and fabricated at the resonant frequency of 1.575 GHz(fur GPS system). For the linear polarization microstrip antenna, the antenna was bent. downward so that the visible length(=L) was reduced by $31.7\%(\varepsilon_r=1.06)$. The folded antenna was folded toward the center of the antenna once again. In this case, the visible length reduction rate, gain, -10 dB bandwidth, E-plane and H-plane HPBW were $73.9\%$, 5.12 dBd, $64MHz(4\%),\;151^{\circ}\;and\;79.2^{\circ}$, respectively. For the circular polarization microstrip antenna, the folded structure of the linear polarization antenna was applied to all the few directions. For the most efficiency the folded bottom surfaces were designed in a triangular shape. In this case, the visible area reduction rate, gain, -10 dB bandwidth, and HPBW in horizontal polarization of the z-x plane and the z-y plane were $71.5\%,\;3.96dBd,\;84MHz(5.3\%),\;80.6^{\circ}\;and\;82.1^{\circ}$, respectively. Therefore, we have confirmed that the folded structure is suitable fer the miniaturization of the microstrip antenna.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.6
• /
• pp.2734-2747
• /
• 2018

In this study, a novel fractal ring antenna with a compact size of $24{\times}9{\times}0.8mm^3$ was configured using three iterations. Low profile, circular polarization, and measured operating bands (4.5-6.5 GHz) meet specifications of the upper band used in Wi-Fi and WiMAX applications. The antenna featured, stable radiation properties, especially gain and efficiency, in the notched band (92%). In deep, the antenna impedance, reflection coefficients, surface current distribution and circular polarization for the three iterations had been studied to improve the process of antenna design and its radiation characteristics.