bs2nlp.mws

syntfil[BS2NLP] - frequency transformation from the non-symmetrical band-rejection (BS) to the normalized lowpass (NLP) filter specification

Calling sequence:

      BS2NLP(fp, fs, f_s, f_p, ap, as)

Parameters:

      fp       - lower cutoff frequency [Hz]

      fs       - lower stopband frequency [Hz]

      f_s      - upper stopband frequency [Hz]

      f_p      - upper cutoff frequency [Hz]

  ap       - passband ripple [dB]

  as       - stopband attenuation [dB]

All parameters must be positive real values, where fp < fs < f_s < f_p   and   ap < as .

Description:

  Os -  stopband frequency of normalized lowpass filter [1/s]

  ap -  passband ripple [dB]

  as -  stopband attenuation [dB]

Info level:

Setting of variable infolevel[syntfil]  can be used to get more detailed results.

infolevel[syntfil] =

      2  - signalize non-symmetrical BS, print new values f_s and fs, passband geometric centre, passband width, stopband width and specification of NLP (Os, ap, as)

      3  - as level 2 + print specification of entered BS (fp, fs, f_s, f_p, ap, as) and plot BS filter specification

      4  - as level 3 + plot specification of NLP

Example:

>    with(syntfil):

`Syntfil version 1.53 loaded`

`You can set infolevel[syntfil] variable to 2..5 to get more detailed results!`

>    infolevel[syntfil]:=1;

infolevel[syntfil] := 1

>    x:=BS2NLP(1000,2000,3000,4000,3,40);

x := 1.800000000, 3, 40

>    infolevel[syntfil]:=4;

infolevel[syntfil] := 4

>    BS2NLP(1000,2000,3000,4000,3,40);

Filter specification:

fp = 1000.000000 Hz

fs = 2000.000000 Hz

f_s = 3000.000000 Hz

f_p = 4000.000000 Hz

ap = 3.000000 dB

as = 40.000000 dB

Non-symetrical BS was entered.

New stopband frequency was calculated fs = 1333.333333 Hz.

fm = 2000.000000 Hz

delta_fp = 3000.000000 Hz

delta_fs = 1666.666667 Hz

[Maple Plot]

Specification of NLP:

Os = 1.800000 1/s

ap = 3.000000 dB

as = 40.000000 dB

[Maple Plot]

1.800000000, 3, 40

See also:

LP2NLP, HP2NLP, BP2NLP, BP22NLP

ButterworthNLPOrder, ChebyshevNLPOrder, CauerNLPOrder