AM and FM Signals Measurement Using Spectrum Analyzers
應用說明
Amplitude modulation (AM) of a sine or cosine carrier results in a variation of the carrier amplitude that is proportional to the amplitude of the modulating signal that contains information. Frequency modulation (FM) is a scheme of angular modulation in which the modulating signal is used to vary the frequency of a carrier wave. The instantaneous frequency of the modulated carrier is directly proportional to the instantaneous amplitude of the modulating signal.Option AMA for the N9340 series Handheld Spectrum Analyzer provides modulation analysis and measurements for AM and FM signals. These measurements include carrier power, modulation rate, modulation index, SINAD, and more. In addition, the baseband modulating signal is displayed after demodulation of the AM/FM carrier. Descriptions of these measurements are given on the following pages.