GCHEBWIN

Purpose:

Generates a Dolph-Chebyshev Window.

GCHEBWIN(N, spacing, attn)

N	-	An integer, the number of points to generate.
spacing	-	A real, the spacing (delta x) between points.
attn	-	Optional. A real, the sidelobe attenuation from the mainlobe in dB. Defaults to -100.

A series.

gchebwin(100,.01)

Creates a 100-point Dolph-Chebyshev window with points spaced at an interval of 0.01. The sidelobe attenuation is -100 dB.

gchebwin(100,.01, -65)

Creates a 100-point Dolph-Chebyshev window with points spaced at an interval of 0.01. The sidelobe attenuation is -65 dB.

W1: gchebwin(100, 1, -60)

W2: magspec(w1, 8192);20*log10(curr/max(curr));

W1 Creates a 100 point Dolph-Chebyshev window where the sidelobe attenuation is -60 dB. W2 displays the normalized frequency response.

The frequency response of an N^thorder Dolph-Chebyshev window with an attenuation of attn decibels is given by:

The time domain response is determined by computing the inverse Fourier transform and scaling the result to a unitary maximum.

The Dolph-Chebyshev windows minimizes the Chebyshev norm of the sidelobes for a given mainlobe width.

The Dolph-Chebyshev window can be regarded as the impulse response of an optimal Chebyshev lowpass filter having a zero-width passband.

Because the Dolph-Chebyshev window yields equiripple constant magnitude sidelobes, impulses may result at the end points of the time domain response.

Use CHEBWIN to automatically create and multiply a Dolph-Chebyshev window with a series. For example:

chebwin(w2, 0, -60)

multiplies Window 2 with a Dolph-Chebyshev window with an attenuation of -60 dB.

See GTAYLORWIN to generate a Taylor window.