Square Wave

The square wave, also called a pulse train, or pulse wave, is a periodic waveform consisting of instantaneous transitions between two levels. The square wave is sometimes also called the Rademacher function. The square wave illustrated above has period 2 and levels
and 1/2. Other common levels for square waves include
and
(digital signals).
Analytic formulas for the square wave
with half-amplitude
, period
, and offset
include
where
is the floor function,
is the sign function, and
is the inverse hyperbolic tangent.
The square wave is implemented in the Wolfram Language as SquareWave[x].
Let the square wave have period
. The square wave function is odd, so the Fourier series has
and
The Fourier series for the square wave with period
, phase offset 0, and half-amplitude 1 is therefore
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(8)
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REFERENCES:
Thompson, A. R.; Moran, J. M.; and Swenson, G. W. Jr. Interferometry and Synthesis in Radio Astronomy. New York: Wiley, p. 203, 1986.