CHEBWIN

Purpose:

Multiplies a series with a Dolph-Chebyshev Window.

Syntax:

CHEBWIN(series, ampflag, attn)

Alternate Syntax:

CHEBWIN(N, ampflag, attn)

Returns:

A series.

Example:

W1: gsin(1000, 0.001, 45)

W2: chebwin(w1)

W1 contains a 1000 point sine wave with a frequency of 45 Hz. W2 multiplies the sine wave with a Dolph-Chebyshev window.

Example:

W1: gsin(1000, 0.001, 45)

W2: chebwin(w1, 0, -65)

Same as the first example except the sidelobe attenuation is -65 dB.

Example:

W1: chebwin(100, 0, -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.

Remarks:

The frequency response of an N^th order 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 GCHEBWIN to generate an N point Dolph-Chebyshev window.

gchebwin(100, 1/100, -60)

creates a 100 point Dolph-Chebyshev window with a sample rate of 0.01 and an attenuation of -60 dB.

See TAYLORWIN to multiply a series with a Taylor window.

See Also:

FFT

GCHEBWIN

GHAMMING

GKAISER

PSD

SPECTRUM

TAYLORWIN

WINFUNC