<< dutycycle | FOSSEE_Signal_Processing_Toolbox | ellipap >>

FOSSEE_Signal_Processing_Toolbox >> FOSSEE_Signal_Processing_Toolbox > ellip

# ellip

Design an elliptic or Cauer filter with specified passband ripple and stopband attenuation.

### Syntax

    [b, a] = ellip(n, rp, rs, wp)
    [b, a] = ellip(n, rp, rs, wp, "high")
    [b, a] = ellip(n, rp, rs, [wl, wh])
    [b, a] = ellip(n, rp, rs, [wl, wh], "stop")
    [z, p, g] = ellip(...)
    [...] = ellip(..., "s")

### Parameters

n:

  Positive integer. The order of the filter.

rp:

  Non-negative scalar. The passband ripple in decibels (dB).

rs:

  Non-negative scalar. The stopband attenuation in decibels (dB).

wp:

  Positive real value. Specifies the passband edge(s):

wl, wh:

  Positive real values. Specify the lower and upper band edges for bandpass or bandstop filters.

z:

  Vector. The zeros of the filter.

p:

  Vector. The poles of the filter.

g:

  Scalar. The gain of the filter.

b:

  Vector. The numerator coefficients of the filter.

a:

  Vector. The denominator coefficients of the filter.

### Description

This function generates an elliptic or Cauer filter with `rp` dB of passband ripple and `rs` dB of stopband attenuation. - [b, a] = ellip(n, rp, rs, wp) designs a lowpass filter with order `n`, passband ripple `rp`, stopband attenuation `rs`, and cutoff frequency `pi*wp` radians. - [b, a] = ellip(n, rp, rs, wp, "high") designs a highpass filter. - [b, a] = ellip(n, rp, rs, [wl, wh]) designs a bandpass filter with edges `pi*wl` and `pi*wh`. - [b, a] = ellip(n, rp, rs, [wl, wh], "stop") designs a bandstop filter. - [z, p, g] = ellip(...) returns the filter in zero-pole-gain form. - [...] = ellip(..., "s") returns an analog filter in Laplace space.

### Examples

    // Lowpass filter:
    [b, a] = ellip(6, 3, 50, 0.6)
    // Highpass filter:
    [b, a] = ellip(6, 3, 50, 0.6, "high")
    // Bandpass filter:
    [b, a] = ellip(5, 1, 90, [0.1, 0.2])
    // Bandstop filter:
    [b, a] = ellip(5, 1, 90, [0.1, 0.2], "stop")
    // Zero-pole-gain form:
    [z, p, g] = ellip(6, 3, 50, 0.6)

### See also

- sftrans, bilinear, zp2tf

Report an issue
<< dutycycle | FOSSEE_Signal_Processing_Toolbox | ellipap >>