Antiresonance Antiresonance In the physics of coupled oscillators, antiresonance, by analogy with resonance, is a pronounced minimum in the amplitude of one oscillator at a particular frequency, accompanied by a large shift in its oscillation phase. Such frequencies are known as the system's antiresonant frequencies, and at these frequencies the oscillation amplitude can drop to almost zero. Antiresonances are caused by destructive interference, for example between an external driving force and interaction with another oscillator. Antiresonances can occur in all types of coupled oscillator systems, including mechanical, acoustic, electromagnetic and quantum systems. They have important applications in the characterization of complex
Amplitude versus offset down the Zoeppritz equations. Due to its physical origin, AVO can also be known as amplitude versus angle (AVA), but AVO is the more commonly used term because the offset is what a geophysicist can vary in order to change the angle of incidence. (See diagram) For a seismic wave reflecting off an interface between two media at normal incidence, the expression for the reflection coefficient is relatively simple: where formula_2 and formula_3 are the acoustic impedances of the first and second medium, respectively. The situation becomes much more complicated in the case of non-normal incidence, due to mode conversion