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Calculadora de Índice de Modulación AM

Calcula el índice de modulación, profundidad de modulación y eficiencia de potencia en modulación AM.

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Fórmula

m = Am / Ac; η = m²/(2 + m²)

mModulation index (0 to 1)
AcCarrier amplitude (V)
AmMessage signal amplitude (V)
BWBandwidth = 2·f_m (Hz)
ηPower efficiency (%)

Cómo Funciona

Amplitude Modulation (AM) is a modulation technique where the amplitude of a carrier signal is varied in proportion to the instantaneous amplitude of the modulating signal while keeping the carrier frequency constant. The modulation index represents the ratio of the amplitude of the modulating signal to the amplitude of the carrier signal, which determines the degree of modulation and the signal's bandwidth. In AM systems, the modulation index directly influences the signal's spectral characteristics and transmission efficiency.

Ejemplo Resuelto

Given: Carrier signal amplitude (Ac) = 10V, Modulating signal amplitude (Am) = 5V Modulation Index (m) = Am / Ac = 5V / 10V = 0.5 This means the modulating signal creates a 50% variation in the carrier signal's amplitude. The modulation index helps determine sidebands, power distribution, and signal quality in AM transmission.

Consejos Prácticos

  • Always ensure the modulating signal amplitude does not exceed the carrier signal amplitude to prevent over-modulation
  • Monitor the modulation index to maintain signal quality and minimize distortion
  • Consider the modulation depth when designing communication systems
  • Use spectrum analyzers to verify modulation characteristics

Errores Comunes

  • Allowing modulation index to exceed 1, which causes signal distortion
  • Neglecting the impact of modulation index on signal bandwidth
  • Failing to account for signal-to-noise ratio changes with modulation

Preguntas Frecuentes

What is the ideal modulation index?

The ideal modulation index is typically between 0.5 and 1, providing efficient signal transmission without excessive distortion.

How does modulation index affect signal bandwidth?

Higher modulation indices increase signal bandwidth, creating more sidebands and potentially requiring wider transmission channels.

Can a modulation index be negative?

No, modulation index is always a positive value representing the relative amplitudes of modulating and carrier signals.

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