• Title/Summary/Keyword: Microstrip Antenna

Search Result 1,025, Processing Time 0.033 seconds

A Study on the Mobile Communication System for the Ultra High Speed Communication Network (초고속 정보통신망을 위한 이동수신 시스템에 관한 연구)

  • Kim, Kab-Ki;Moon, Myung-Ho;Shin, Dong-Hun;Lee, Jong-Arc
    • Journal of IKEEE
    • /
    • v.2 no.1 s.2
    • /
    • pp.1-14
    • /
    • 1998
  • In this paper, Antenna, LNA, Mixer, VCO, and Modulation/Demodulation in Baseband processor which are the RF main components in Wireless LAN system for ultra high-speed communications network are studied. Antenna bandwidth and selective fading due to multipath can be major obstacles in high speed digital communications. To solve this problem, wide band MSA which has loop-structure magnetic antenna characteristics is designed. Distributed mixer using dual-gate GaAs MESFET can achieve over 10dB LO/RF isolation without hybrid, and minimize circuit size. As linear mixing signal is produced, distortions can be decreased at baseband signals. Conversion gain is achieved by mixing and amplification simultaneously. Mixer is designed to have wide band characteristics using distributed amplifier. In VCO design, Oscillator design method by large signal analysis is used to produce stable signal. Modulation/Demodulation system in baseband processor, DS/SS technique which is robust against noise and interference is used to eliminate the effect of multipath propagation. DQPSK modulation technique with M-sequences for wideband PN spreading signals is adopted because of BER characteristic and high speed digital signal transmission.

  • PDF

Cavity-Backed Slot Array Antenna for a Repeater System of a Satellite Digital Multimedia Broadcasting (위성 DMB 중계기용 Cavity-Backed슬롯 배열 안테나)

  • Jung Hee-Chul;Lee Hak-Yong;Jung Byungwoon;Kang Gi-Cho;Park Myun-Joo;Lee Byungje
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.16 no.4 s.95
    • /
    • pp.366-372
    • /
    • 2005
  • This paper presents analysis of a slot array antenna having a low side lobe level and high front-to-back ratio for a repeater system of a satellite DMB(Digital Multimedia Broadcasting) service. Antennas for this repeater system require a high gain and enough isolation to reduce interferences between signals in system. Therefore, it is necessary to suppress a side lobe level and to increase front-to-back ratio. Unlike a structure 134 by lossy microstrip lines, in this work a single cavity-backed slot antenna array using a single waveguide feed is proposed to obtain the reliability for high power handling and high radiation efficiency. The side lobe level and front-to-back ratio are enhanced with tapered array technique and an optimized vertical reflector. The measured side lobe levels in H- and E-plane are under $-33.24\;\cal{dB}$ and $-35.78\;\cal{dB}$, respectively. The front-to-back ratio over $37.84\;\cal{dB}$, and the peak gain of over $17\;\cal{dBi}$ are measured.

Development of a V-band Rotman Lens Using Thin-Film Dielectric (Thin-Film Dielectric을 이용한 V-band Rotman Lens의 개발)

  • Lee, Jang-Soo;Park, Sang-Bok;Lee, Dong-Kyu;Song, Saeng-Seob;Lee, Sang-Hyo;So, Joon-Ho;Kwon, Young-Woo;Seo, Kwang-Seok;Cheon, Chang-Yul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.17 no.11 s.114
    • /
    • pp.1073-1081
    • /
    • 2006
  • In this paper, a phased array antenna based on thin-film dielectric technology at 60 GHz is designed. In order to reduce dividing/combining loss and avoid high loss of phase shifters, Rotman Lens has been employed as a feeder of antenna. The lens has 3 beam ports and 5 array ports with 2 dummy ports. The simulation for the design was performed by simulator using MoM(method of moments). The measured results of fabricated lens show magnitude deviation less than ${\pm}2dB$ and phase aberration less than ${\pm}5^{\circ}$ over $58{\sim}62GHz$. The antenna shows ${\pm}7^{\circ}$ of scan angles.

Design and Manufacture of Triple-Band Antennas with Modified Rectangular Ring and Rectangular Patch for WLAN/WiMAX system applications (변형된 사각 링과 사각 패치를 갖는 WLAN/WiMAX 시스템에 적용 가능한 삼중대역 안테나 설계 및 제작)

  • Kim, Woo-Su;Yoon, Joong-Han
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.23 no.3
    • /
    • pp.341-348
    • /
    • 2019
  • In this paper, a monopole type antenna applicable to WLAN and WiMAX standard frequency bands is designed and fabricated. The proposed antenna is designed to have rectangular ring and rectangular patch based on microstrip feeding for triple band characteristics and inserted two stub in the top of the rectangular ring patch to enhance impedance bandwidth characteristics. The proposed antenna has $18.0mm(2W_1+W_2){\times}33.0mm(L_7+L_8+L_9)$ on a dielectric substrate of $27.0mm(W_1){\times}44mm(L_1){\times}1.0mm$ size. From the fabrication and measurement results, impedance bandwidths of 660MHz (2,08 to 2.74GHz) for 2.4/2.5MHz band, 488MHz (3.40 to 3.88GHz) for 3.5MHz band, and 2,180MHz (4.61 to 6.79GHz) for 5,000MHz band were obtained based on the impedance bandwidth. The proposed antenna also obtained the measured gain and radiation pattern in the anechoic chamber.

A Novel Feed Network for a Sectoral Conical Beam (분할된 원추형 빔 형성을 위한 안테나 급전 구조)

  • Kim, Jae-Hee;Park, Wee-Sang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.20 no.5
    • /
    • pp.413-420
    • /
    • 2009
  • We propose a novel feed network for a $2{\times}2$ array antenna to form a sectoral conical beam. The proposed feed network, which is a symmetrical structure, consists of four $90^{\circ}$ hybrids, a crossover, and four $90^{\circ}$ delay lines. To verify the performance of the feed network a $2{\times}2$ array antenna and the feed network are fabricated on a microstrip structure, and the radiation patterns are measured at the center frequency of 2.57 GHz. The maximum radiation is measured at the $45^{\circ}$ elevation angle and at the $45^{\circ}$, $135^{\circ}$, $225^{\circ}$, and $315^{\circ}$ azimuth angles depending on the choice of the input port of the feed network.

Implementation of Down Converter for Ku-Band Application (Ku 대역용 주파수변환기의 구현)

  • 정동근;김상태;하천수
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.4 no.3
    • /
    • pp.527-536
    • /
    • 2000
  • This paper discusses the design of self-oscillating mixer type low noise down converter using the microwave field effect transistor. The mixer is consists of local oscillator in which high stability dielectric resonator and band pass filter to get rid of spurious oscillation at intermediate frequency stage. The microstrip antenna was integrated in the same substrate which generate 12.3GHz and low noise amplifier was also added after antenna using 3 stage of high electron mobility transistors. The output frequency from the local oscillator was chosen as 11.3GHz for the Ku-band application. The measured phase noise was -804dBc/Hz at 100kHz offset frequency, and the gain was 7~12dB in frequency range from 12.0GHz to 12.7GHz. The noise figure at intermediate frequency stage was 64H. The designed model shows less conversion loss than previous diode type mixer. The proposed mixer can be used in digital satellite broadcasting and communication system and expected to use in next generation low noise block design.

  • PDF

Radiation Characteristics of the Bianisotropic Superstrate-Loaded Microstrip Antenna on Cylindrical Bianisotropic Substrates (쌍이방성 기판에 쌍이방성 덮개층을 갖는 원통형 마이크로스트립안테나의 방사특성)

  • Yoon, Joong-Han;Choi, Byung-Ha
    • Journal of IKEEE
    • /
    • v.3 no.1 s.4
    • /
    • pp.29-38
    • /
    • 1999
  • In this paper, the effects of superstrate on the radiation patterns of dipole on cylindrical bianisotropic subtrates were studied. Special constitutive relations are used to describe the bianisotropic properties of a material, such that the Green's function can be formulated. Electromagnetic fields and hounds conditions in spectral region were used to find Creen's function of the spectral representation and electromagnetic fields in space region were derived through inverse Fourier transformations of fields in spectral region using asymptotic formula for far zone. Radiation characteristics of axial Hertzian dipole on superstrate leaded cylindrical bianisotropic substrates were analyzed.

  • PDF

A Compact Rotman Lens with Wide Angle Steering Characteristics (광각 빔조향 특성을 갖는 소형 로트만 렌즈)

  • 이광일;김인선;오승엽
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.13 no.5
    • /
    • pp.500-506
    • /
    • 2002
  • This paper presents a design of wide angle steering microstrip Rotman lens operating over broadband frequency range for Electronic Warfare equipments. It has a compact and simple structure which it is easy to manufacture repetitively. The lens is modelled as a 2-dimension planar circuit, the contour integral method is performed over entire lens contour and the transmission coefficients from 8 beam ports to 8 array ports are found. The measured results are well agreed with those of analysis. Prediction of the multibeam array pattern fed by linear array antenna shows $\pm$65$^{\circ}$ of beam steering and $\pm$5 dB insertion loss deviation over 3:1 frequency range.

Analysis of Electrostatic Field and Potential Distributions in Conductor-Backed Coupled Coplanar Waveguide Using Conformal Mapping Method (등각사상방법을 이용한 도체로 보강된 결합 도파 선로의 정전기장과 전위 분포 해석)

  • Yoo, Tae-Hoon;Han, Ki-Soo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.24 no.6
    • /
    • pp.35-42
    • /
    • 2010
  • We use conformal mapping method to derive the analytical expressions for calculating electrostatic fields and electric potentials surrounding the conductor-backed coupled coplanar waveguide(CBCCPW) structure. Using the derived expressions, the electrostatic fields and potentials are computed at various points of the CBCCPW's geometry and the field and potential distributions are analyzed. The proposed method provides a faster and simpler calculation of the field distributions than the full-wave analysis method because no iterations are required. This method can be widely applied to the analysis of microwave integrated circuits using coupled line, such as coupler, filter, and microstrip antenna.

A Low Noise Amplifier and a Minimized microstrip Patch Antenna for GPS (Global Positioning System) (Global Positioning System용 저잡음 증폭기와 초소형 마이크로스트립 안테나)

  • 박노승;이병제;이종철;김종헌;김남영
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
    • /
    • 2000.11a
    • /
    • pp.385-388
    • /
    • 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.

  • PDF