• Title/Summary/Keyword: Spurious Frequency

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Finite Difference Time Domain Analysis for Film Bulk Acoustic Wave Resonator used in Microwave Region (시간 영역 유한 차분법(FDTD)을 이용한 마이크로파 대역의 압전 박막 공진기 해석)

  • 송영민;정재호;이용현;이정희;최현철
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.489-492
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    • 2000
  • Film Bulk Acoustic Wave Resonator(FBAR) used in microwave region was analyzed with Finite Difference Time-Domain Methods(FDTD) in this paper. FBAR have been analyzed with one dimensional Mason model analysis or Finite Element methods(FEM), but the first couldn't analyze effect of area variation and spurious characteristics, the second had difficulty in element separation because of thin electrode. So in this paper FBAR was analyzed by Finite Difference Time-Domain Methods and it's results were transformed to frequency domain using Discrete Fourier Transform.

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Measurement of Sonobuoy Transmitting Antenna System for Anti-Submarine Warfare

  • Min Kyeong-Sik
    • Journal of electromagnetic engineering and science
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    • v.5 no.2
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    • pp.97-103
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    • 2005
  • This paper describes the measured results of sonobuoy transmitting antenna system for anti-submarine warfare (ASW). Since radiation pattern and power density depend on impedance matching between transmitting RF part and antenna with termination resistance, design of matching circuit is very important for sonobuoy system performance. Matching circuit is designed by Smith chart using control of L and C. In standing wave ratio(SWR) measurement using Network Analyzer, SWR of antenna with matching circuit observed 1.5 below at the assigned VHF band. It shows very excellent performance comparison with conversional product that is used for the same object. The measured vertical and horizontal radiation patterns are also shown the satisfaction of military specifications. A drop out of sonobuoy system on the sea is happened when angle of elevation direction is over 10 degrees, and it is conformed that it takes less than I second return to original signal level. The required electric power density is $83\;mW/m^2$ in the military specification, and measured electric power density is observed over average $110\;mW/m^2$ at all frequency bands.

Analysis on Decomposition Models of Univariate Hydrologic Time Series for Multi-Scale Approach

  • Kwon, Hyun-Han;Moon, Young-Il;Shin, Dong-Jun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1450-1454
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    • 2006
  • Empirical mode decomposition (EMD) is applied to analyze time series characterized with nonlinearity and nonstationarity. This decomposition could be utilized to construct finite and small number intrinsic mode functions (IMF) that describe complicated time series, while admitting the Hilbert transformation properties. EMD has the capability of being adaptive, capture local characteristics, and applicable to nonlinear and nonstationary processes. Unlike discrete wavelet transform (DWT), IMF eliminates spurious harmonics and retains meaningful instantaneous frequencies. Examples based on data representing natural phenomena are given to demonstrate highlight the power of this method in contrast and comparison of other ones. A presentation of the energy-frequency-time distribution of these signals found to be more informative and intuitive when based on Hilbert transformation.

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Design and Implementation of Up-converter for WCDMA Digital Optic Repeater (WCDMA 디지털 광 중계기용 Up-converter 설계 및 제작)

  • 최영선;강원구;장인봉
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.586-589
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    • 2003
  • Repeater is developed. Based on the systems The up-converter of the WCDMA Digital Optic pecifications, the structure of the up-converter is accomplished and its block diagram is drawn. The up-converter is implemented according to these block diagrams. Subsequently the low pass filter, the automatic level controlled attenuator, the frequency synthesizer and other components for the up-converter are designed and implemented, and a main board to integrate these modules is also manufactured. To reduce the noise floor of system and suppress the RF spurious noise, a PCB layout is performed carefully. For each module consisting of the up-converter and the entire system, the performance tests are accomplished to check the performance about the specifications.

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A Study on the Receiving Performance Improvement of Digital Mobile Communication (디지털 이동통신의 수신성능개선에 관한 연구)

  • 주재한
    • Journal of the Korea Computer Industry Society
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    • v.2 no.11
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    • pp.1477-1482
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    • 2001
  • In this paper, we examined receiving parameters of receiver and also analyzed them through simulation based on J-STD-018, which is the minimum specification of PCS mobile station. Receiving system was made a passive double balance mixer which has low gain and high IIP3, and an intermediate frequency amplifier for enhancing the low gain. The result of simulating receiving parameter is as follows: noise figure which is the parameter of specification of the receiving sensitivity is 6.746dB, IIP3 which is the parameter of specification of the intermodulation spurious response attenuation is -11.358dBm.

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A Design and Performance Analysis of the Fast Scan Digital-IF FFT Receiver for Spectrum Monitoring (스펙트럼 감시를 위한 고속 탐색 디지털-IF FFT 수신기 설계 및 분석)

  • Choi, Jun-Ho;Nah, Sun-Phil;Park, Cheol-Sun;Yang, Jong-Won;Park, Young-Mi
    • Journal of the Korea Institute of Military Science and Technology
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    • v.9 no.3
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    • pp.116-122
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    • 2006
  • A fast scan digital-IF FFT receiver at the radio communication band is presented for spectrum monitoring applications. It is composed of three parts: RF front-end, fast LO board, and signal processing board. It has about 19GHz/s scan rate, multi frequency resolution from 10kHz to 2.5kHz, and high sensitivity of below -99dBm. The design and performance analysis of the digital-IF FFT receiver are presented.

An analysis of arbitrarily shaped planar circulators (임의의 모양을 갖는 평면형 서큘레이터의 해석)

  • 정중성;김병욱;전동석;윤상원;장익수
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.5
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    • pp.75-84
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    • 1996
  • planar circulator swith arbitrarily shaped ferrite resonators are analyzed in this paper. First, resonant frequencies and field distributions for the magnetized ferrite resonator are obtained using finite element method (FEM). Then the RF voltage distributions and other circuit parameters of the circulator which is formed by connecting three suitable transmission lines ot the ferrite resonator are derived from the green function . To remove the spurious solutions in analyzing the ferrite resonator, the results of eigenvalue analysis by node based FEM are comapred with the edge based fEM. The green function is expanded in terms of normalized eigenfunctions of th ecorresponding wave equation. Circulator parameters for circular disk resonator are clculated and compared with the analytical results. The experimental data for the designed circulator using hexagonal reosnator in the 850 MHz frequency range agree well iwth the simulated data.

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A 90°-Bent Spur-Line Combined CRLH ZOR Bandpass Filter for the Channel of the UWB Communication System

  • Lee, Changhyeong;Kahng, Sungtek
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.928-935
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    • 2018
  • In this paper, a compact fully printable bandpass filter is suggested for a low-frequency channel 3.2 GHz ~ 3.7 GHz in the Ultra-Wideband (UWB) communication system. It is featured with a small geometry of $0.5{\lambda}_g/15$ and a low insertion loss despite using FR4 as a cheap substrate of a high dielectric loss. This is made possible by generating zeroth-order-resonance (ZOR) from one cell comprising two series resonances obviously separated from one shunt resonance as a third-order bandpass filter. Especially, the series resonance elements are combined with spur-lines bent by 90 degrees, which makes the port-impedance matched well and eliminates spurious hikes in the stopband, while the overall size remains almost unchanged. The design is carried out by setting up the equivalent circuit and the circuit simulation is checked by the full-wave EM analysis. The structure is manufactured and measured to show that the circuit modeling and EM simulation results agree with the measured data.

Optimal Shape Design of Waveguide Matched Load Using 3 Dimensional Vector Finite Element Method (3차원 벡터유한요소법을 이용한 도파관 정합부하의 최적형상설계)

  • Kim, Jun-O;Lee, Hong-Bae;Cheon, Chang-Yul;Hahn, Song-Yop;Kim, Hyeong-Seok
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1213-1215
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    • 1994
  • The shape of lossy material inside a waveguide matched load is optimally designed to give low reflection over a given frequency range. The 3 dimensional vector finite element mettled is used as an analysis tool which does not generate spurious mode. The optimizing process used in this parer is the Powell technique. The designed load gives the low reflection about -30 dB around 10GHz with 1.5 wavelength of the load length.

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The Development of Dual Mode Convergence Home Gateway System based upon Broadcast & Telecommunication Convergence Networks (방송통신융합망 기반의 Dual Mode 융.복합 홈 게이트웨이 시스템 개발)

  • Park, No-Jin
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.9 no.1
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    • pp.29-34
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    • 2010
  • In this study, we realized the broadband home gateway system of dual mode based upon EDR 2~3Mbps transmission speed and 300Mbps of 802.11n, In broadcasting and telecommunication convergence networks to deliver multimedia services, high-quality home. The bluetooth module is designed to use general low rate data speed service and the 802.11n module also is designed to use high rate speed service at various home network situation. The dual mode home gateway system, bluetooth and 802.l1n module, is well realized for many specification such as emission power, spurious power, impedance matching, frequency channel test.

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