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Dual-band chip antenna design using intercoupling capacitance
Choi, Hyengcheul,Kim, Hyeongdong Wiley Subscription Services, Inc., A Wiley Company 2009 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.51 No.6
<P>For the dual-band (GSM/DCS) operation, the second-order resonance is used to operate in the high frequency range. To control the bandwidth characteristics in each band, an intercoupling capacitance between the radiating elements is utilized to satisfy the bandwidth requirements of GSM (890–960 MHz) and DCS (1710–1880 MHz) cellular communications systems. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1467–1470, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24374</P>
Design of a Dual-Band Chip Antenna Using a Gap-Fed Branch
CHOI, Hyengcheul,KIM, Hyeongdong The Institute of Electronics, Information and Comm 2009 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.92 No.8
<P>Dual-band chip antennas usually have a narrow bandwidth in the first resonance frequency band due to an inter-coupling capacitance. In order to analyze the effect of the inter-coupling capacitance, an equivalent circuit of an antenna with a branch radiator is considered in this paper. Based on the equivalent circuit model, it is found that the inter-coupling capacitance reduces impedance bandwidth. This paper proposes a gap feeding method to alleviate the effect of the inter-coupling capacitance and explains it using an equivalent circuit.</P>
최형철(Hyengcheul Choi),이형진(Hyungjin Lee),박범기(Bumki Park),장진혁(Jinhyuk Jang),김형동(Hyeongdong Kim) 한국전자파학회 2012 한국전자파학회논문지 Vol.23 No.2
본 논문은 안테나 구조 없이 리액티브 소자 만을 이용하여 단말기 그라운드를 방사체로 활용하는 방법을 소개한다. 안테나의 특성은 블루투스 대역에서 동일 그라운드 면적(40×20 ㎟)을 가지는 미앤더 IFA와 비교하여 분석하였다. 시뮬레이션 및 측정을 통해 캐패시터 소자 만을 이용한 안테나가 가장 높은 방사 효율을 나타내는 것으로 판명되었다. 이는 안테나의 인덕턴스가 높을수록 그라운드의 방사 저항이 감소하고, 캐패시터의 손실 저항이 인덕터 또는 IFA보다 낮기 때문이다. 높은 방사 효율에도 불구하고 제안하는 안테나의 면적(5×2.5 ㎟)은 IFA의 면적(12×2.5 ㎟)의 반 이하이다. This paper introduces the method to utilize a terminal ground as a radiator only using reactive components without an antenna structure. Characteristics of the proposed antenna is compared with that of the meander IFA on the same ground plane(40×20 ㎟) for the bluetooth band. From simulation and measurement data, it is found that the proposed antenna using only capacitors provides the highest radiation efficiency. This is because of that the higher inductance reduces radiation resistance of a ground and the capacitor has a lower loss resistance comparing to that of the IFA or the inductor. In spite of the high radiation efficiency, the area (5×2.5 ㎟) of the proposed antenna is less than half of the area (12×2.5 ㎟) of the IFA.
Circular Polarization Dielectric Resonator Antenna Excited by Single Loop Feed
Sinhyung Jeon,Hyengcheul Choi,Hyeongdong Kim 한국전자통신연구원 2009 ETRI Journal Vol.31 No.1
A new feeding method for the circular polarization (CP) dielectric resonator antenna (DRA) is proposed in this letter. Two orthogonal modes (TExδ11, TEy1δ1) of the rectangular DRA are excited by a 90-degree phase difference of the differential and common modes currents of the proposed feeding structure. To demonstrate the good CP performance of the proposed method, a right-hand CP DRA for a global positioning system was designed. The impedance bandwidth of the proposed antenna for S11<-10 dB and 3 dB axial ratio bandwidth are about 5.4% and 1.95% at 1.57 GHz, respectively.
Planar Inverted-E (PIE) Antenna for a Wide Impedance Bandwidth
JEON, Sinhyung,CHOI, Hyengcheul,KIM, Hyeongdong The Institute of Electronics, Information and Comm 2010 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.93 No.11
<P>A planar inverted-E (PIE) antenna that can achieve a wide impedance bandwidth is proposed. The antenna is realized by inserting a branch capacitance between the feed line and the shorting pin of a conventional planar inverted-F antenna (PIFA). Such a modification significantly enhanced the impedance bandwidth while maintaining the antenna size. The proposed antenna possesses a very wide impedance bandwidth of 1250MHz (1650-2900MHz) at a voltage standing wave ratio (VSWR) <3. In addition, good radiation patterns were obtained at the desired frequency bands.</P>
Design of GPS Antenna using Dielectric Resonator
Sinhyung Jeon,Hyengcheul Choi,Hojeong Kim,Junghwan Yeom,Hyeongdong Kim 대한전자공학회 2008 ITC-CSCC :International Technical Conference on Ci Vol.2008 No.7
In this paper, the design of the RHCP (right hand circular polarization) dielectric resonator antenna for GPS (Global Positioning Systems) is proposed. For the miniaturization size of antenna, high-permittivity dielectric (εr=30) is used. Also in order to obtain circular polarization of low-profile rectangular dielectric resonator antenna, the proposed antenna is simply excited by single strip line. The proposed single feeding method consisting of a loop shape can easily excite two orthogonal modes (TE<SUP>x</SUP>δ11, TE<SUP>y</SUP>δ11) within the single resonator and easily achieve circular polarization. Using EM simulation, antenna characteristic parameters are found. Based on these results, antenna is manufactured. The simulated and measured results of proposed design are presented.
Critical coupling of a planar inverted F-antenna using a ferrite sheet
Kim, Hojeong,Choi, Hyengcheul,Jeon, Sinhyung,Kim, Hyeongdong Wiley Subscription Services, Inc., A Wiley Company 2010 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.52 No.2
<P>In this letter, a novel method that can achieve critical coupling in a planar inverted F-antenna of high height is proposed. Theproposed antenna can achieve critical coupling by attachment of a ferrite sheet without changing the size of the antenna or ground plane. A ferrite sheet is used to increase shunt inductance of the shorting pin loop. The proposed antenna is modeled by an equivalent circuit based on transmission line modeling. It has a very wide bandwidth of 16% for a voltage standing wave ratios <2. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 400–403, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24950</P>
Hybrid Planar Inverted-F Antenna with a T-Shaped Slot on the Ground Plane
Sinhyung Jeon,Hyengcheul Choi,김형동 한국전자통신연구원 2009 ETRI Journal Vol.31 No.5
In this letter, a novel hybrid planar inverted-F antenna (PIFA) with a T-shaped slot on the ground plane is proposed. The loop structure formed by the feed line and shorting pin can be operated as a series and shunt inductance for the PIFA and the T-shaped slot antenna, respectively. The PIFA operates at a frequency of 1.75 GHz, while the T-shaped slot on the ground plane operates at 2.4 GHz by the same voltage feeding source. The height of the PIFA is 6.5 mm, and the size of an upper patch is designed to be 30 mm × 16 mm. The measured relative impedance bandwidth of the PIFA and the T-shaped slot are about 12% and 21%, respectively. In addition, good antenna performance was achieved.
Compact Hybrid DRA Combined with PIFA
YEOM, Junghwan,JEON, Sinhyung,CHOI, Hyengcheul,KIM, Hyeongdong The Institute of Electronics, Information and Comm 2010 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.93 No.10
<P>A dielectric resonator antenna (DRA) is located below a radiating patch of an planar inverted F antenna (PIFA) to achieve a compact hybrid antenna and a multiple band operation. Loop-type structures with PIFA shorting pins are used as feeds for both the DRA and the PIFA. The proposed antenna operates well in two frequency bands without perturbing the fundamental radiation characteristics of each operating radiation mode of the DRA and the PIFA. Its electromagnetic performance and the desirable practical size of the proposed hybrid antenna are attractive for small mobile communication devices.</P>