• Title/Summary/Keyword: HPBW

Search Result 37, Processing Time 0.035 seconds

High Gain and Broadband SAP Antenna with Two Parasitic Patches (두 개의 기생 패치를 갖는 고 이득.광대역 SAP 안테나)

  • Kim, Jung-Han;Kim, Yong-Jin;Lee, Hong-Min
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.18 no.8
    • /
    • pp.930-936
    • /
    • 2007
  • In this paper, the high gain and broadband antenna operating for SDMB(Satellite Digital Multimedia Broadcasting) system is realized, The proposed antenna consists of the SAP(Shorted Annular Patch) structure, which inhibits surface-wave and the parasitic SAP element with spacing of $0.25 {\lambda}_0$ in order to improve gain, bandwidth and directivity. The RHCP(Right Hand Circular Polarization) is generated by two slits, which are made along the periphery of the circular patch at the diametrically opposite points, The simulated maximum gain of the proposed antenna is 12.6 dBi, which is better 5.22 dBi than maximum gain of the conventional microstrip patch antenna. The measured maximum gain is 10.5dBi at operating frequency 2.63GHz. Also, the measured impedance bandwidth$(VSWR{\leq}2)$ of the proposed antenna is $360MHz(2.488{\sim}2.848 GHz)$, which is better 300 MHz than the bandwidth of the conventional microstrip patch antenna. The measured HPBW(Half Power Beam Width) of the proposed antenna is $45.8^{\circ}$, and the measured FBR(Front to Back Ratio) is 15.49 dBi, The 3dB axial ratio bandwidth is 220 MHz$(2.54{\sim}2.76 GHz)$.

Analysis of the Radiation Patterns of Satellite SAR System with Active-Transponder (능동전파반사기를 이용한 위성 SAR 시스템 방사 패턴 분석)

  • Hwang, Ji-Hwan;Kweon, Soon-Koo;Oh, Yisok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.23 no.10
    • /
    • pp.1204-1211
    • /
    • 2012
  • Measurement and analysis results of the extracted radiation-patterns from the field-experiments which were conducted to acquire the generic technology for calibration and validation of the satellite SAR system(Synthetic Aperture Radar) are presented in this study. Prototype of active transponder is adjustable within maximum 63.1 dBsm of RCS (Radar Cross Section) and includes the receiving-function with external receiver. To increase an accuracy of these field experiments, we repetitively measured satellite SAR systems of the same operating mode(i.e., COSMO-SkyMed No. 2 & 3, hh-pol., strip-map himage mode, 3 m resolution). Then, the reliability of experimental results was cross-checked through analysis of the RCS of active transponder on SAR image. The property of azimuth radiation patterns of satellite SAR system extracted from them has $0.352^{\circ}$ of HPBW(half-power beamwidth), $0.691^{\circ}$ of FNBW(first-null beamwidth), and 11.17 dB of PSLR(peak to side lobe ratio), respectively.

Design and Manufacture of X-Band 10 X 10 Waveguide Slot Array Antenna for SAR (SAR용 X-밴드 10 10도파관 슬롯 배열 안테나 설계 및 제작)

  • 신영종;이범선
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.15 no.11
    • /
    • pp.1019-1025
    • /
    • 2004
  • The X-band 10${\times}$10 waveguide slot array antenna for SAR is designed, fabricated and measured. The array antenna is designed using the equivalent circuit model based on the field distribution of the dominant mode, TE$\sub$10/, and EM simulation. The method to decide optimum angle of the centered inclined slot(coupling slot) and the optimum of offset of the longitudinal slot(radiating slot) is provided. The designed antenna structure is EM simulated and fabricated. The measured return loss bandwidth is 180 MHz at 9.15 GHz , the side lobe level is below -25 dB, HPBW is about 9$^{\circ}$, and the gain is 25.5 dB. These results are similar to the simulation data.

Design of a 0.5~2 GHz Cavity-Backed Spiral Antenna (0.5~2 GHz 캐비티 백 스파이럴 안테나 설계)

  • Jeon, Nam-Du;Shin, Dong-Hoon;Park, Dong-Chul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.21 no.3
    • /
    • pp.269-277
    • /
    • 2010
  • In this paper, the design of a 0.5~2 GHz cavity-backed spiral antenna is described. Combined arm pattern with a log spiral in the inner region and an Archimedean spiral in the outer region, a backing cavity, and a Marchand coaxial balun for feeding are designed. Termination resistors are used to improve antenna characteristics at the lower frequency of the operation frequency. VSWR, axial ratio, gain and HPBW(Half Power Beam Width) characteristics are simulated using CST's MWS. Finally, the validity of these approaches is verified by comparing the simulated results with the measured ones. Also, the measurement results are compared with the performance of a commercial spiral antenna.

Broadband multimode antenna and its array for wireless communication base stations

  • Wu, Rui;Chu, Qing-Xin
    • ETRI Journal
    • /
    • v.41 no.2
    • /
    • pp.167-175
    • /
    • 2019
  • A wideband dual-polarized antenna coupling cross resonator is proposed for LTE700/GSM850/GSM900 base stations. An additional resonance is introduced to obtain strong coupling between the dipole and resonator. Moreover, the input impedance of the proposed antenna is steadily close to $50{\Omega}$, which results in better impedance matching. Therefore, a wide bandwidth can be achieved with multiresonance. A prototype is fabricated to verify the proposed design. The measured results show that the antenna has a fractional bandwidth of 35.7% from 690 MHz to 990 MHz for ${\mid}S_{11}{\mid}$ < -15 dB. Stable radiation patterns as well as gain are also obtained over the entire operating band. Moreover, a five-element antenna array with an electrical downtilt of $0^{\circ}$to $14^{\circ}$ is developed for modern base station applications. Measurement shows that a wide impedance bandwidth of 34.7% (690 MHz to 980 MHz), stable HPBW (3-dB beamwidth) of $65{\pm}5^{\circ}$, and high gain of $13.8{\pm}0.6dBi$ are achieved with electrical downtilts of $0^{\circ}$, $7^{\circ}$, and $14^{\circ}$.

Design of Circularly Polarization Patch Array Antenna for DSRC (DSRC 통신을 위한 원형 편파 패치 배열 안테나 설계)

  • Kim, Hyun-Chul;Jung, Jin-Woo;Lee, Hyeon-Jin;Lim, Yeong-Seog
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.23 no.2
    • /
    • pp.144-150
    • /
    • 2012
  • In this paper, circularly polarization patch array antenna of RSE(Road-side Equipment) base station for DSRC(Dedicated Short Range Communication) of ITS(Intelligent Transport System) is proposed. The antenna of RSE base station for DSRC is designed to operate circularly polarization to receive reflected signal from multiplex path effectively. The proposed antenna consisted of microstrip patch and feed line, the slit is inserted in the proximity of the slot of feed structure to generate circularly polarization. The $2{\times}2$ array structure is designed to satisfying gain that DSRC RSE base station antenna required. Measured impedance bandwidth and axial-ratio bandwidth are satisfied by all DSRC band of 5.795~5.855 GHz. Vertical and horizontal HPBW of the proposed antenna are both about 43 degrees, it showed gain characteristic of about 11.21 dBi.

A Broadband CPS-Fed Yagi-Uda Antenna (CPS 급전 방식의 광대역 Yagi-Uda 안테나)

  • Han, Kyung-Ho;Park, Yong-Bae;Choo, Ho-Sung;Park, Ik-Mo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.20 no.7
    • /
    • pp.608-616
    • /
    • 2009
  • This paper presents a broadband CPS-fed Yagi-Uda antenna. The antenna has a feedline structure much simpler than other Yagi-Uda antennas and it provides more design flexibility in arranging the reflector. To improve the impedance matching, a tapered CPS line is inserted between the thick and thin feedlines. The proposed antenna exhibits the bandwidth of $3.9{\sim}5.9$ GHz (|G| < -10 dB) and the gain of $6.5{\sim}8$ dBi within that bandwidth. At the center frequency of 4.9 GHz, the antenna shows the gain of 7.4 dBi, and HPBW of $98^{\circ}$ along the x-z plane and $73^{\circ}$ along the x-y plane.

Study on Wave Propagation Characteristics Modeling in Tunnel (터널 환경에서의 전파전파 특성 모델링 연구)

  • Jeong, Won-Jeong;Kim, Tae-Hong;Han, Il-Tak;Choi, Moon-Young;Ryu, Joon-Gyu;Lee, Ho-Jin;Pack, Jeong-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.20 no.9
    • /
    • pp.1003-1013
    • /
    • 2009
  • In the domestic environments, there are many tunnels since most of terrains have mountains. To ensure the quality of wireless network service in NLOS environment like tunnels which differ from indoor or outdoor wireless channels, researches on wave-propagation characteristics. through such channel are necessary. Especially, in such environment the ground repeater called Gap-Fillers are usually used for satellite mobile services. To make sure that mobile service using satellites in tunnels is available, the research about Gap Filling method is essential. This research is focus on the characterising the wave-propagation through tunnels, to find the appropriate frequency, HPBW of the Gap-Filler antennas, the number of Gap-Fillers, etc. In this paper, we present the effective Gap Filling method in tunnels for ISM band, based on analysis of ray tracing and measurement results.

A Study on the Improvement of the Directivity for Rectangular Microstrip Patch Array Antennas Conformed to a Cylindrical Surface (원통면에 정합-배열된 장방형 마이크로스트립 패치 안테나의 지향성 개선을 위한 연구)

  • 고광태;구연건
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.5 no.2
    • /
    • pp.46-54
    • /
    • 1994
  • In this paper, an analysis and design method is proposed, which is to improve the directivity of microstrip array antennas conformed to a cylindrical surface. In the case of forming an arc-array in the circumferential direction on a circula-cylinder surface, the circular-cylinder can be approximated to a polygonal-pillar and on each pillar-planes the sub-arrays, Dolph-Tschebyscheff array and uniform array with a beam steered in the desired direction, would make a sharp directivity for the total cylin- drical array antenna. And the radiation pattern according to the type of its sub arrays is analyzed and compared using the cylindrical-cavity codel. A cylindrical microstrip array antenna, with 12 elements and uniform arra as a sub-array which have an equal distance$\lambda_0$/2between the elements, is manufactured and conformed to a cylinder with radius of 6 The measured data of side lobe level, HPBW and FNBW are - 13dB, $9^{\circ}$, and $15{\circ}$, ,respectively. This result shows a good improvement on the directivity comparing with a linear array.

  • PDF

Design of 4×4 Array Synthesis Horn Antenna and Radiated Power Measurement by Magnetron (4×4 배열 합성 혼 안테나 및 고출력 마그네트론에 의한 방사전력 측정)

  • Ko, Dong-Ok;Shin, Jae-Yoon;Woo, Jong-Myung
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.15 no.5
    • /
    • pp.108-115
    • /
    • 2016
  • In this paper, the array synthesis horn antenna was designed and measured a radiation power after connecting magnetron. The proposed antenna was designed on the basis of the $4{\times}4$ array synthesis horn antenna characteristics. For suppressing a back-lobe, 2 step short-stub structures were attached to synthesis horn aperture upper and lower. The designed antenna has FBR(Front to Back Ratio) of 39.7 dB. HPBW(Half Power Beam Width) of the E-plane and the H-plane are $8.86^{\circ}$ and $7.35^{\circ}$ each in the measurement. For measuring a radiation power of array antenna that use a magnetron, the waveguide adaptor was designed and connected magnetron with horn antenna. Also, microstrip line coupler that replace a dielectric material with an air gap was designed for measuring a high power. As a result, average radiation output power of the $4{\times}4$ array synthesis horn antenna that connect a four magnetrons had a 0.063W.