• Title/Summary/Keyword: FM modulation

Search Result 102, Processing Time 0.025 seconds

Development of an UHF CW/FM Proximity Sensor System (UHF CW/FM 전파 근접 감지 시스템의 개발)

  • 최재현;임인성;한상철;오승엽
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.8 no.4
    • /
    • pp.363-372
    • /
    • 1997
  • We have developed the UHF CW/FM proximity sensor system. The UHF CW/FM Proximity Sensor is the system which recognizes the distance from the antenna to the target using the UHF band signal. To adjust sensing distance, we must change modulation frequency parameter or modulation index parameter. When we select the modulation frequency paramter for adjusting sensing distance, new modulation frequency generator and new band pass filter will be required. It is so inefficient that we choose modulation index parameters for adjusting sensing distance. In this paper, theoretical principles of the UHF CW/FM Proximity Sensor are analyzed and doppler signals for the distance from the antenna to the target are measured as the modulation index($\beta$) being changed. Three systems of which moduation indices are 38, 50, and 61 are made. We concluded that the sensing distance will decrease as the modulation index($\beta$) increases. It is in accord with the theory of this UHF CW/FM Proximity Sensor System.

  • PDF

PCM/FM With Modulation Index of 2/3 (변조지수가 2/3인 PCM/FM)

  • Gu, Young Mo
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.49 no.11
    • /
    • pp.941-944
    • /
    • 2021
  • PCM/FM with a modulation index of 0.7 is widely used in the telemetry field. If the modulation index is slightly changed to 2/3, it can be interpreted as 3-PSK with a state number of 3 in phase transition trellis and can be received with a simple Viterbi decoder. As a result of computer simulation, the Eb/No performance in the AWGN channel is about 8.3 dB when the BER is 10-5, which is close to the theoretical limit.

Demodulation and Performance of Multicomponent Undersampled AM, FM and AM-FM Signals (다중 성분의 저표본화된 AM, FM 및 AM-FM 신호들의 복조와 성능)

  • Son, Tae-Ho;Hwang, Ui-Cheon
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.49 no.7
    • /
    • pp.399-406
    • /
    • 2000
  • We propose an nonlinear demodulation algorithm for undersampled multicomponent AM(Amplitude Modulation), FM(Frequency Modulation) and AM-FM signals. First, we derive respectively undersampling frequency of the AM, FM and AM-FM using undersampling scheme, and separate respectively monocomponent signals from multicomponent signals using periodic algebraic separation algorithm. In this case augmented separation matrix is very regular and sparse, it has a special structure. The proposed demodulation algorithm detects respectively message signals of the IA(Instantaneous Amplitude) and IF(Instantaneous Frequency) from descrete monocomponent AM, FM and AM-FM signals with an undersampling frequency to be controllable. Verifying the RMS(Root Mean Squares) errors of the detected signals, we show that the performance is excellent.

  • PDF

Digital Demodulator Design and Characteristics Using Algebraic Separation and Energy Operator from Undersampled Two-Component AM-FM Signals (저표본화된 주성분의 AM-FM 신호들로부터 대수적 분리와 에너지 연산자를 사용한 복조기 설계 및 특성)

  • Sohn, Tae-Ho;Lee, Min-Ho
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.48 no.5
    • /
    • pp.643-649
    • /
    • 1999
  • In this paper, we proposed that i) noise-tolerant four kinds of AM(Amplitude Modulation)-FM(Frequency Modulation) demodulators are designed, ⅱ) we derived undersampling frequency through the product via energy operator of the monocomponent AM-FM signals separated form two-component AM-FM signals, and ⅲ) these four kinds of AM-FM demodulators detect respectively information signals of the IA(Instantaneous Amplitude) and IF(Instantaneous Frequency) by undersampling frequency to be different each other from the undersampled monocomponet AM-FM signals. Particularly, the proposed algorithm can control undersampling frequency by an integer factor. And these efficient AM-FM demodulators are well worked with the undersampled AM-FM signals.

  • PDF

Design and Implementation of a Novel Frequency Modulation Circuit using Phase Locked Synthesizer (PLL Synthesizer를 이용한 새로운 FM 회로 설계 및 제작)

  • Yang, Seong-Sik;Lee, Jong-Hwan;Yeom, Kyung-Whan
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
    • /
    • 2003.11a
    • /
    • pp.224-228
    • /
    • 2003
  • In this paper, for phase lock loop(PLL) synthesizer, we introduce a novel but simple and low cost frequency modulation(FM) circuit of a flat peak frequency deviation for modulation signal from high to very low frequency penetrating into the loop-bandwidth of PLL. The FM circuit was basically designed to compensate an amount of feedback of the loop filter in PLL. The circuit also includes the capability of the adjustment of peak frequency deviation and blocking the interference with the loop filter. The designed circuit was successfully implemented and showed the flat frequency deviation as expected in the design.

  • PDF

Design and Implementation of a Novel Frequency Modulation Circuit using Phase Locked Loop Synthesizer (PLL 주파수 합성기를 이용한 새로운 주파수 변조 회로 설계 및 제작)

  • 양승식;이종환;염경환
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.15 no.6
    • /
    • pp.599-607
    • /
    • 2004
  • In this paper, using phase locked loop(PLL) synthesizer, we introduce a novel but simple and low cost frequency modulation(FM) circuit of a flat peak frequency deviation fur modulation signal whose frequency covers from outside to inside of the loop-bandwidth of PLL. The FM circuit was basically designed to compensate an amount of feedback of the loop filter in PLL. The circuit also includes the capability of the adjustment of peak frequency deviation and of blocking the intereference with the loop filter. The designed circuit was successfully implemented and showed the flat frequency deviation as expected in the design. In addition, the novel measurement method of the wideband FM modulation index is suggested verified With the suggest measurement, it can be successfully shown the designed circuit has the expected frequency deviation.

연속 파장 가변시 현상론적인 비 선형 이득 포화 효과가 다전극 DBR 레이저의 변조 특성에 미치는 영향

  • Lee, S.;Park, N.;Park, H. L.;Choi, W. J.;Han, I. K.;Lee, J. I.;Kang, K. N.
    • Korean Journal of Optics and Photonics
    • /
    • v.4 no.3
    • /
    • pp.301-308
    • /
    • 1993
  • Phenomenological nonlinear gain saturation effect on the modulation characteristics in a multi-electrode DBR laser, when the lasing wavelength changes, continuously is analized theoretically. FM efficiency, 3 dB bandwidth, and resonance frequency decrease with increasing bias current to the passive section, except increasing the flat FM response. It is found that the nonlinear gain saturation effect severely affects the modulation characteristics such as FM/IM response, 3 dB bandwidth, resonance frequency and CPR, but hardly affects the behavior of continuous frequency tuning.

  • PDF

An Implementation of FM-extended Stereo System via Application of Quadrature Modulation and Companding Method (직교 변조 및 압신 방식을 이용한 확장형 FM 스테레오 방식의 구현)

  • Heo, Dong-Kyu;Kim, Kee-Keun;Kim, Ju-Koang;Ryu, Heung-Gyoon
    • The Journal of the Acoustical Society of Korea
    • /
    • v.10 no.2
    • /
    • pp.44-51
    • /
    • 1991
  • In this paper, we have studied the FM-extended broadcasting which makes the enhancement of stereo signal-to-noise ration by utilizing the compression technique and quadrature moduation method of standard subcarrier signal in transmitter station, and corresponding demodulation method and expansion technique in receiver system. The proposed system is completely compatible with the conventional FM stereo system. We have confirmed the validity of the proposed method by implementation of transmitter/receiver system including quadrature modulation/demodulation and companding system.

  • PDF

Implementation of DS/SS(FM-DS/SS) system using FM (FM을 이용한 DS/SS(FM-DS/SS) 시스템의 구현)

  • 정명덕;박지언;변건식
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.9 no.1
    • /
    • pp.98-107
    • /
    • 1998
  • For implementation of FM-DS/SS system. This paper has analyzed SO(Synchronous Oscillator) being oscillated by the motivation of injected signal. Transmitter has adopted FM-DS/SS modulation method using RF output-signal of FM. Receiver is used SO to demodulation of FM-DS/SS and applied sliding correlator for synchronization of PN clock. As a result of the inspection, SO presented stable lock ability in spite of doppler apperance and proved the synchronous properties of it in the FM-DS/SS system.

  • PDF

Sound Synthesis of Piri by Asymmetric Frequency Modulation (비대칭 FM합성방식을 이용한 피리 소리의 합성)

  • Pyoun, Joong-Bae;Cho, Sang-Jin;Chong, Ui-Pil
    • Proceedings of the Korea Institute of Convergence Signal Processing
    • /
    • 2006.06a
    • /
    • pp.37-40
    • /
    • 2006
  • FM(Frequency Modulation) 음 합성방식은 오랫동안 연구되어 왔고 여러 가지 효과를 주기에 유용하고 비교적 낮은 사양으로 높은 수준의 배음을 합성할 수 있지만 그 응용분야가 대부분이 서양악기 위주의 연구였다. 이에 본 논문에서는 국악 관악기인 피리를 주파수 영역에서 저주파 영역과 고주파 영역으로 나누어 분석하고 이 결과를 이용하여 FM 파라미터를 추출하고 비대칭 FM합성방식으로 1차적인 소리를 합성하였다. 분석된 저주파 영역과 고주파 영역의 특성을 각각의 역 필터링을 위한 2개의 필터를 설계하여 이를 다시 합성된 소리를 통과시켜 두 소리를 합산함으로써 더욱 원음과 유사한 소리를 합성할 수 있었다.

  • PDF