• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.7A
• /
• pp.511-519
• /
• 2003

In this paper, to achieve a broad-band and high-gain antenna, we thus designed and analyzed the CRLPDA(Corner Reflector Antenna feeding by Log-Periodic Dipole Antenna) made up of 90$^{\circ}$corner reflector, which is trough-reflector type installed a planar reflector at the folded line. CRLPDA for operating frequency band of 1,400 MHB ~ 2,400 MHz was designed and radiation characteristics of the designed antenna were analyzed by moment method. To verify the analysis results, CRLPDA was fabricated and the calculated results were compared with the measured results. The measured results showed good agreement with the calculated results. As the result of measurements, bandwidth(VSWR＞2) for 1,000 MHz was achieved and gain was 13 dBi.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.12 s.91
• /
• pp.1131-1140
• /
• 2004

In this paper, we proposed a flate-plate antenna employing semi-annular slots for satellite broadcast reception. The radiating element of the antenna is dual annular slots fed by a strip dipole, which have a wider bandwidth than the rectangular slot. A $16{\times}16$ array antenna is designed using stripline T-junction power dividers. Measurements of the fabricated antenna show a gain of 28.0$\~$29.5 dB in 11.7$\~$12.8 GHz frequency range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.9
• /
• pp.971-978
• /
• 2010

In this paper, we propose a compact multiple meander RFID tag antenna with broadband characteristic. The proposed tag antenna has been designed using the multiple meander form to effectively minimize the U-shaped half wavelength dipole antenna as the radiator part. The commercial tag chip is attached to the upper center of the rectangular shaped feed for impedance matching. The size of the antenna is $20{\times}19.7\;mm^2$ and VSWR<5.8 bandwidth is 855~964 MHz which covers the world UHF RFID bandwidth.

• Journal of Convergence for Information Technology
• /
• v.7 no.2
• /
• pp.37-42
• /
• 2017

In order to estimate chaff RCS, we suggest here a novel method using the probability distribution. Normally, a chaff is assumed that it is a thin dipole antenna and the RCS can be calculated by the scattering wave theory. Most of the theoretical methods presented were mainly focusing on a single chaff cloud. In this paper, the RCS calculation was done for two or more chaff clouds and the changes of RCS with azimuth angle were observed. Matlab was used for presenting the probability distribution of chaff clouds and RCS calculation. A more accurate RCS estimation method is suggested by estimating the number of chaffs except the blocked elements.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.11
• /
• pp.42-47
• /
• 2007

In this paper, influence of lossy ground and gap variation between lossy ground and UWB antenna on impulse propagation in time domain for impulse ground penetrating radar (GPR) is numerically and experimentally investigated. For this study, a novel planar UWB fat dipole antenna is developed. First, influence of lossy ground and gap variation between lossy ground and UWB antenna is simulated. For verification, a test field of sand and wet clay soil is built and using the developed dipole antenna, transmission behavior is investigated at the test field. With an aid of IDFT (inverse discrete Fourier transform), time domain impulse response for transmission coefficient measured and simulated in frequency domain is obtained. Measurement and simulation show that the frequency of maximum transmission coefficient and transmission coefficient are increased with higher dielectric constant and larger gap distance. In time domain, it is shown that for higher dielectric constant, the amplitude of the received signal in time domain is higher and reflected signals are seriously modified. Also, it is found that variation of gap between antenna and ground surface makes timing of peak value changed.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.5
• /
• pp.197-203
• /
• 2016

In this paper, the dipole antenna that can control a beam steering were designed for attaching on LEO(Low Earth Orbit) small satellite. The proposed antenna was based on Yagi-Uda antenna. The parasitic element was proposed as a T-shape. Depending on the state of open or short at the end of a vertical element, we can choose a characteristic of the parasitic element with fixing a vertical element length of the parasitic element. Using this characteristic, we designed the director element and reflector element. The proposed antenna was designed to receive UHF 436.5 MHz. Antenna gain was chosen by link budget between one satellite and the other satellite or between the satellite and the ground station. By changing a vertical element length which is the largest variable that chooses an antenna characteristic, we confirmed that ${\lambda}/2$ length transformer has a result that improve 0.5 dB in comparison ${\lambda}/4$ length transformer from maximum gain direction. In production, we made an on/off switch composed of a diode, capacitor, and inductor control an open and short at the end of the parasitic element. As a result, the gain of antenna used in a link between one satellite and the other satellite had average 5.92 dBi. And the gain of antenna used in a link between the satellite and the ground station had average 0.99 dBi.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.20 no.4
• /
• pp.83-94
• /
• 2021

In this paper, we proposed a microstrip antenna (center frequency 118 MHz) with an omnidirectional radiation pattern that can replace the antennae used in VDB systems in GBAS. First, to obtain an omnidirectional radiation pattern from a microstrip antenna, we constructed a folded antenna. We then designed a miniaturized triple-folded antenna using perturbation effects. Thus we obtained suitable characteristics with a S₁₁ of -13.91dB, -10 dB bandwidth of 1.5 MHz (1.27%) in the center frequency of 118 MHz. Furthermore, in the yz-plane and xy-plane, the component exhibits an omnidirectional radiation pattern, and the size of the antenna achieves miniaturization of 64.2% compared to the reference antenna. Finally, it is suitable as an antenna for VDB systems in GBAS.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.2 no.1
• /
• pp.65-72
• /
• 2009

For the evaluation of far-field performance by using the near-field probing on the base station dipole array antenna, the effects of mutual coupling depending on the heights between the array antenna with reflector and the probe were analyzed. When the height is varied in the near-field region, S parameters on the input ports of antenna and probe are measured and analyzed to decide the height for the minimum mutual coupling effect and the maximum probing efficiency. This height will be applicable to the near-field probing system design to achieve the precision far-field performance of a base station array antenna system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.6
• /
• pp.550-557
• /
• 2003

In this paper, two dualband internal antennas for GPS/PCS handset are proposed. At first, the monopole antenna with parasitic dipole element is designed to print PCB of handset directly. At second, the antenna with bended loop structure is designed to bend to use internal space of handset maximumly. The proposed dualband internal antennas provide a 2:1 VSWR bandwidth of over 19.1 % which are possible to cover two bands at once. the antennas have a gain between -0.4 and 3.33 ㏈i at all bands and they have almost omni-directional patterns.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.05a
• /
• pp.475-476
• /
• 2015

In this paper, we introduce a novel feeding method for a broadband planar quasi-Yagi antenna (QYA) for terrestrial digital television (DTV) receiving. The balun between the balanced coplanar strip (CPS) line feeding the driver dipole and the unblanaced microstrip line is a rectangular patch inserted into the CPS line along the center of the CPS. The end of the balun is connected to the CPS line through a shorting pin. The effects of various geometrical parameters and balun on the antenna characteristics are examined. An antenna, as an design example for the proposed antenna, is designed for the operation in the frequency band of 470-806 MHz for terrestrial DTV.