Antiresonance in magnitude and opposite in phase. The principle of antiresonance is used in wave traps, which are sometimes inserted in series with antennas of radio receivers to block the flow of alternating current at the frequency of an interfering station, while allowing other frequencies to pass. 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
Negative frequency is just a constant whose amplitude level is a measure of the strength of the original "ω" content. And whatever part of "x"("t") that was at frequency zero is changed to a sinusoid at frequency −"ω". Similarly, all other frequencies are changed to non-zero values. As the interval increases, the contribution of the constant term grows in proportion. But the contributions of the sinusoidal terms only oscillate around zero. So "X"("ω") improves as a relative measure of the amount of frequency "ω" in the function "x"("t"). The Fourier transform of formula_1 produces a non-zero response only at frequency "ω". The