• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.4 s.19
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• pp.20-25
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• 2004

The existing antenna that equipped with Micro Aerial Vehicle, microstrip antenna only can send and receive image signal because of limited bandwidth. But, proposed antenna that equipped with Micro Aerial Vehicle flight introduces tapered type patch antenna, also improves bandwidth then can transfer present location, altitude, movement speed. Furthermore, as a result of introduce stacked type, it transfers more quality of image signal, and represents most suitable performance in Korean peninsula that has many mountain peaks. In this paper, to transmit and receive the wideband signals with a antenna system, the wideband microstrip antenna is proposed and designed. This antenna operates at 2.4GHz. In this thesis, the resonance frequency of 2.4GHz and the reflective loss of the antenna of -22dB were calculated by measuring the fabricated Tapered Microstrip Patch Antenna which was designed with the resonance of 2.4GHz. The calculated gain and efficiency of antenna were 6.7dB and $60\%$ respectively. The characteristic of the bandwidth shows with $50\~60MHz$ which is $6.02\%$ at the basis of -l5dB reflective loss. The experimental results can be used in the characteristic of the resonators and this antenna produces a greatly enhanced bandwidth.

• 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.

• ETRI Journal
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• v.34 no.1
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• pp.1-8
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• 2012

This paper proposes a reconfigurable beam-steering antenna using a bended dipole and a loop. The radiation patterns of the two antennas are cancelled or compensated, and headed towards a specific direction when the dipole and loop antenna are combined at a reasonable ratio. The proposed antenna can steer the beam directions by controlling the operation of two artificial switches. The proposed antenna was manufactured on a PCB (FR-4) and a flexible PCB (polyimide). In the case of the antenna that was fabricated on a PCB, the maximum beam directions were $+50^{\circ}$, $0^{\circ}$, and $-50^{\circ}$ in the azimuth direction using the two artificial switches, and the antenna gain was 1.96 dBi to 2.48 dBi in the operation bandwidth of 2.47 GHz to 2.53 GHz. Also, the antenna was fabricated on a flexible PCB and measured under various bending conditions for wearable applications.

• 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.

• Journal of electromagnetic engineering and science
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• v.7 no.3
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• pp.138-146
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• 2007

In this paper, a monopole antenna of conical-cylindrical compound shape is presented. The conventional circular conical monopole antenna is modified by placing a cylinder at the top of the inverted cone. The cylindrical portion is useful in the wide band impedance matching, in adjusting the antenna gain in the horizontal direction, and in reducing the cone diameter. The dependence of the antenna performance on various geometric parameters is investigated using a commercial electromagnetic simulation software, from which an optimum design of the antenna is derived. The diameter of the circular ground plane is minimized to 115 wavelength at the lowest operating frequency. The antenna proposed in this study shows a reflection coefficient less than -10 dB and a 1${\sim}$6 dBi gain over 3${\sim}$20 GHz frequencies. The antenna shows a circular-symmetric radiation pattern in the horizontal plane and a null-free pattern in the vertical direction over the whole operating frequency range.

• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5745-5758
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• 2017

In this paper, we develop a simple but very effective 4 by 4 Multiple-Input Multiple-Output (MIMO) antenna system for mobile phones consisting of different types of antennas to achieve low correlation property at the frequency ranges of 1710 to 2170 MHz, which covers wide LTE service bands, from band 1 to band 4. The proposed antenna system consists of two pair of antennas. Each pair consists of a planar inverted-F antenna (PIFA) and a coupling antenna which has the property of the loop. The use of two different antenna types of IFA and a coupling achieves high isolation. Proposed antenna system occupies relatively small area and positions at the four corners of a printed circuit board. The gap between the two antennas is 4 mm, in order to realize the good isolation performance. To evaluate the performance of our proposed antenna system, we perform various experiments. The proposed antenna shows a wide operating bandwidth greater than 460 MHz with isolation between the feeding ports higher than 17.5-dB. It also shows that the proposed antenna has low Envelop Correlation Coefficient (ECC) values smaller than 0.08 over the all desired frequency tuning ranges.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.4
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• pp.119-125
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• 2007

In this paper, a miniaturized PCB-integrated antenna is proposed for bluetooth applications. The proposed antenna is a modified form of the printed inverted F antenna where the size reduction is achieved by employing the meander strip for the resonant length part of the radiator. The antenna dimension is optimized using the commercial electromagnetic software MWSTM. The designed antenna is fabricated by the standard photo-etching technique and its performance is measured. The fabricated antenna shows a bandwidth of 125MHz centered at 2.45GHz and a gail of -0.23dBi. The size of the proposed antenna is $9.65mm{\times}5.95mm$ corresponding to the 55 percent of the area of the existing printed inverted F antenna.

• 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 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%.