A new modulation-index measuring instrument for square-wave FM signal
説明
A method measuring the modulation indexes of square wave frequency modulation (SWFM) signals have been proposed and experimentally verified. The measurement circuit consists of a series of bandpass filters, DC rectifiers, analog-to-digital converters, and a processor for calculating the frequency deviation. In accordance with the modulation index of the SWFM signal at the fundamental and third-harmonic frequency of the IF carrier, the frequency deviation of the SWFM signal has been found to be precisely determined when the modulation signal is input to the SWFM signal modulator. This method is useful for determining suitable modulation signal levels for sideband spreading in the SWFM signal, and can be applied to the measurement of the modulation index at the transmitter in FM voice communication systems. >
収録刊行物
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- [1992] Conference Record IEEE Instrumentation and Measurement Technology Conference
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[1992] Conference Record IEEE Instrumentation and Measurement Technology Conference 52-55, 2003-01-02
IEEE