• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.393-400
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• 2015

As the development and distribution of the intelligent transport system is spreading recently and some of the services are commercialized through a pilot project, interest in DSRC with high utilization is increasing and antennas for roadside and on board equipment are being studied. A single patch was used for a vehicle antenna due to the requests of miniaturization of size, but there was performance degradation in most cases due to miniaturization. In addition, some methods to improve performance have been used in the antennas that were previously researched using the arrays, but they have the disadvantages of bulkiness in size of the antennas when using the arrays. Therefore, in this paper, the CPW fed microstrip patch antenna with the simple structure of being compact and easy to produce, which can be used in the OBU of DSRC, was designed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1659-1665
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• 2019

In this paper, a novel design of a compact printed monopole antenna for wireless local area network (WLAN) applications is investigated. The radiator with a patch of different line width and step-shaped ground planes is used to reduce the antenna size. The size of the antenna is 16 × 17 × 1 ㎣ and is fabricated with a photolithography technique. The simulated and measured results agree well. The resonant frequency of the investigated antenna is about 5.2 GHz and can cover an impedance bandwidth of 1 GHz for the measurement result. In addition, we presented the measured radiation pattern, presented the gain and efficiency measured in the required WLAN 5 GHz frequency band (5.15-5.825 GHz), and confirmed that it can be used as a 5 GHz band WLAN antenna. The investigated antenna has a small size, light weight, low cost, omni-directional radiation pattern, high gain, and high efficiency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1071-1078
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• 2003

In this paper, the planar, compact, and broadband phased array antenna system for IMT-2000 applications has been investigated. Two methods far designing a low-cost and low-complex beam-farming network are proposed. First, a new compact and broadband phase shifter with continuously controlled phase bits is designed by using parallel coupled lines. Second, its equivalent phase delay line is suggested to be capable of replacing the complex phase shifter with a reference phase bit on a phased array antenna. For the purpose of achieving the broadband system, in addition to the broadband phase shifter, a wide-slot antenna with a ground reflector is utilized as an element antenna. Therefore, the phased array antenna system has achieved compact size, broad bandwidth, and wide steering angle, although it has low complexity and low fabrication cost. The 3${\times}$1 phased array antenna system has a compact size of 1.6 λ${\times}$ l.6 λ, which is the sufficient ground plane of the wide-slot antenna. Experimental results present that the S$\_$11/ has less than 15 dB within the band and its radiation patterns on an E-plane have the capability of steering an antenna beam from -29$^{\circ}$to +30$^{\circ}$.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.385-388
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• 2000

본 논문에서는 좀더 효율적이고 소형화한 GPS(Global Positioning System)용 안테나와 LNA(Low Noise Amplifier)를 IMT-2000 단말기에 내장함으로써 개인 휴대 통신 기능과 더불어 좀 더 정확한 위치추적 기능을 동시에 가능케 하고자 한다. 중심 주파수 1.575 GHz의 저잡음 증폭기와 안테나의 크기는, 합쳐서 10$\times$10$\times$4 (mm)로서 상층은 마이크로스트립 패치 안테나이고, 중간층은 안테나 ground와 LNA ground의 공통 ground이며, 제일 아래층에는 LNA가 위치하게 된다. LNA 의 경우 2단을 중첩하여, 첫째 단 16dB, 둘째 단 18dB의 이득 특성을 보였는데 첫째, 둘째 단의 대역통과 필터에서 삽입손실로 3dB의 손실을 가져와 총 3dB의 이득 특성을 보였다. 잡음 특성은 약 1.9의 특성을 보였다. 안테나의 경우 9$\times$9$\times$$\times$2 (mm)로써, 고유전율( $\varepsilon$$_{r}$ = 73 )의 세라믹을 사용하여 그 크기를 상당부분 줄였다. 그리고 유전체 밑의 ground를 옆면까지 높임으로써 좀 더 소형화한 안테나를 가능케 하였다. 고유전율의 유전체를 사용하였기에 안테나 자체의 이득 특성은 저잡음 증폭기에서 보상하고, 안테나의 임피던스 정합 또한 LNA의 입력 쪽에서 하도록 하였다. 또한 위성신호 수신을 위해 안테나는 RHCP 의 원형편파 특성을 갖는다.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.35-40
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• 2012

In this paper, we present the size reduction method of HF whip antenna for ship communication. To reduce the size of the HF whip, the end part of linear whip is modified to helical type. We designed the whip antenna with 60% size of the commercial whip antenna and carried out communication experiments using the commercial and the designed whip antennas. From the experimental results, we found that the proposed whip antenna can replace the commercial whip antenna for ship communication.

• 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.

• 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.526-533
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• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.81-82
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• 2016

In this paper, a design method for a compact log-periodic half-bow-tie dipole array antenna for an operation in UWB band is studied. The proposed antenna is miniaturized by using half-bow-tie shaped dipole elements instead of strip-type dipole elements, which are commonly used in general log-periodic dipole array antenna, and by reducing the element spacing. The effects of the flare angle of the half-bow-tie elements and the element spacing on input reflection coefficient and realized gain characteristics of the proposed log-periodic antenna are analyzed. The optimized antenna is designed on FR4 substrate, and it operates in the frequency band of 3.05-13.96 GHz for a VSWR < 2, which assures the operation in the UWB band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.8
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• pp.865-871
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• 2010

A compact dual-band(IEEE 802.11b: 2.4~2.5 GHz, 11a: 5.15~5.825 GHz) 2-channel MIMO antenna for PMP applications is presented. The proposed antenna is composed of a planar inverted F-shape antenna(PIFA) operating at 2 GHz band and a loop antenna operating at 5 GHz band. The proposed antenna is orthogonally arranged at the edge of the ground plane for polarization and pattern diversities with excellent isolation characteristics. The two PIFA antennas operating 2 GHz have connecting line($\lambda_g$/4) face to the feed point for high isolation and low correlation at 2 GHz band. The two loop antennas connected each other in the bottom side to improve the isolation at 5 GHz band. The proposed antenna has a sufficient gain in WLAN service band and is compact sized for the portable media player (PMP) applications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.906-912
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• 2008

We designed and implemented a 3-dimensional structure internal antenna which has volume less than 1.5 cc for mobile phone to improve efficiency and gain. Multiple bending for the resonance of small internal antenna derives reduction of gain due to cancellation of antenna current. In this study, the current cancelation was reduced by the minimization of antenna bending. And the helix element was applied for the purpose both compensation of short antenna length and action of radiation element. For the verification of this study, a 1.5 cc volume 3D antenna which was fabricated by the press method applied to the dual band mobile phone. Measurement showed that efficiencies and gains under the slide down and up were 27.73 %, 0.29 dBi for the GSM band and 46.84 %, 2.27 dBi for the USPCS band, and had good performance under the small antenna volume. H-plane radiation pattern showed omnidirectional for the both band.