• 전기의세계
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• v.14 no.1
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• pp.13-25
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• 1965

A super gain antenna relating to TV & FM broadcasting for Seoul area is designed and manufactured. It is analyzeied with the equivalent circuit, and then manufactured according to the design method. Some practical measurements pertaining to various characteristics of the antenna have been accomplished and shown us good results.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1053-1060
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• 2019

The satellite antenna for collecting information is mainly classified into reflector antenna, lens antenna, and phased array antenna. Among them, the phased array antenna with the excellent antenna pattern control performance for a multi-beam system is frequently used. Although the terrestrial signal information collection based on the satellite is not much effected geographically, it requires the accurate angle-of-arrival (AOA) information of the interesting signal. In this paper, we discuss the characteristics and the advantages/disadvantages of the antenna array shape employed in the phased array antenna. In addition, we present the Cascade AOA estimation algorithm based on a square array antenna mounted on the satellite receiver, and show the performance evaluation results through the computer simulation.

• Journal of electromagnetic engineering and science
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• v.15 no.3
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• pp.185-193
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• 2015

In this paper, a hybrid multiple input multiple output (MIMO) antenna for eight-band mobile handsets is designed and implemented. For the MIMO antenna, two hybrid antennas are laid symmetrically and connected by an interconnection tie, thereby enabling complementary operation. The tie affects both the impedance and radiation characteristics of each antenna. Further, printed circuit board (PCB) embedded type is applied to the antenna design. To verify the results of this study, we designed eight bands-LTE class 12, 13, and 14, CDMA, GSM900, DCS1800, PCS, and WCDMA-and implemented them on a bare board the same size as the real board of a handset. The voltage standing wave ratio (VSWR) is within 3:1 over the entire design band. Antenna isolation is less than -15 dB at the lower band, and -12 dB at the WCDMA band. Envelope correlation coefficient (ECC) of 0.0002-0.05 is obtained for all bands. The average gain and efficiency are measured to range from -4.69 dBi to -2.88 dBi and 33.99% to 51.5% for antenna 1, and -4.74 dBi to -2.97 dBi and 33.45% to 50.49% for antenna 2, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1024-1029
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• 2003

This paper presents the complex antenna factor of a top-hat EMI monopole antenna for measuring time domain electromagnetic fields. The approach is facilitated by adding a artificial parallel ground plane above the monopole antenna. This allows use of cylindrical harmonic field expansions in each of three subregions enclosed by the two ground plane. The results show that the complex antenna factor of the top-hat monopole antenna does not diverge at low frequencies. When compared with a monopole antenna, the top-hat monopole antenna has broadband characteristics. In order to verify the availability of the mode-matching method, the input impedance of the antenna were compared with experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.63-64
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• 2017

In this paper, we studied a design method for a coplanar waveguide-fed compact quasi-Yagi antenna for a dual band of the UHF RFID (915 MHz) and GPS (1.575 GHz). The proposed antenna is composed of three elements of a dipole, a reflector, and a director. To reduce its size, the ends of both the dipole and reflector are bent, the director is placed near to the dipole, and a balun is incorporated in the antenna. From some simulations, the proposed antenna using an FR4 substrate with 0.8 mm thickness was designed for the operations in the UHF RFID and GPS systems, and the antenna characteristics such as reflection coefficient, gain, and radiation patterns were examined.

• Journal of information and communication convergence engineering
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• v.13 no.2
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• pp.81-85
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• 2015

A 94-GHz phased array antenna using a log-periodic antenna has been developed on a GaAs substrate. The developed phased array antenna comprises four log-periodic antennas, a phase shifter, and a Wilkinson power divider. This antenna was fabricated using the standard microwave monolithic integrated circuit (MMIC) process including an air bridge for unipolar circuit implementations on the same GaAs substrate. The total chip size of the fabricated phased array antenna is 4.8 mm × 4.5 mm. Measurement results showed that the fabricated phased array antenna had a very wide band performance from 80 GHz to 110 GHz with return loss characteristics better than -10 dB. In the center frequency of 94 GHz, the fabricated phased array antenna showed a return loss of -16 dB and a gain of 4.43 dBi. The developed antenna is expected to be widely applied in many applications at W-band frequency.

• Journal of electromagnetic engineering and science
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• v.19 no.2
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• pp.115-121
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• 2019

This paper presents the effects of the position of the split of a split-ring resonator (SRR) on the performance of a composite broadband printed dipole antenna. The antenna is made of two printed dipole arms enclosed by two rectangular and identically printed SRRs. One dipole arm and the SRR are printed on the top side of the substrate, while the other dipole arm and SRR are printed on the bottom side of the same substrate. By changing the position of the split on the SRR, different antenna characteristic values are obtained, namely, for impedance bandwidth and radiation patterns. The split position is thus a critical parameter in antenna design, because it influences the antenna's major performance immensely. Different split positions and their consequences for antenna performance are demonstrated and discussed. The antenna generates linearly polarized radiations, and it is computationally characterized for broadband characteristics. The optimized compact antenna has overall dimensions of 9.6 mm × 74.4 mm × 0.508 mm (0.06λ × 0.469λ × 0.0032λ at 1.895 GHz) with a measured fractional bandwidth of 60.31% (1.32 to 2.46 GHz for |S₁₁| <-10 dB) and a radiation efficiency of >88%.

• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.314-324
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• 2006

The vacuum characteristics of the KSTAR ICRF antenna were experimentally investigated. The fabricated antenna was installed in the RF Test Chamber(RFTC) which has a vacuum system with an effective pumping speed of 1015 l/s. The time variations of RFTC pressure, total gas load and ultimate pressure were measured before the RF test. RF conditioning effect was studied by repeating RF pulses at low power level. A time variation of the RFTC pressure was measured during a RF power was applied to the antenna. Threshold pressure at which a RF breakdown occurs was investigated. Whenever the pressure was higher than $10^{-4}$ mbar, the RF breakdown occurred. During a long pulse testing, the temperature of the antenna and RFTC pressure were measured to investigate long pulse limitation of the maximum available voltage without any cooling, which were compared with testing results with a water cooling of the antenna.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.119-126
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• 2019

In this paper, a monopole antenna applicable to WLAN standardization is designed, fabricated, and tested. The proposed antenna is designed to have three microstrip lines based on microstrip feeding method and inserted one stub to enhance impedance characteristics. Then, it obtained triple band characteristics of the proposed antenna. We adjusted and optimized the lengths and width of the three microstrip lines and one inserted stub to obtain the required impedance bandwidth for this paper. The proposed antenna has $23.0mm(W){\times}53.1mm(L1)$ on a dielectric substrate of $24.0mm(W1){\times}60.0mm(L){\times}1.0mm$ size. From the fabrication and measurement results, bandwidths of 158 MHz (841 to 1000 MHz) for 900 MHz band, 630 MHz (2.32 to 2.95 GHz) for 2400 MHz band, and 1,040 MHz (4.95 to 5.99 GHz) for 5000 MHz band were obtained based on the impedance bandwidth. The fabricated antenna also obtained the measured gain and radiation pattern characteristics in the required triple band of the proposed antenna.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.593-600
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• 2020

The equipment for marine IoT service have to overcome the effect of seawater. Furthermore, the free floating transmitter in seawater will be less affected by the seawater environment. The results of the design and fabrication of antenna, which is embedded in buoy, are shown in this research. The proposed antenna is used to supervise the states of fishing gears in monitoring system for real-name system of electric fishing gear. The selected frequency band of the proposed antenna is 920 MHz, and PCB pattern type is selected for subminiature and light weight. It is confirmed that RF characteristics is more degraded, however, the radiation is gradually upward as the contact surface of buoy with seawater is more broaden through the simulation results. That is, the RF performance of the proposed antenna is more deteriorated but beam radiation characteristics is more suited the marine IoT, the seawater effect is more increased. It is expected that the proposed antenna will contribute the implementation of IoT network based on low power wide area (LPWA) when the degradation of RF performance will be settled.