elemsbp.html

elemsbp.mws

syntfil[ElemsBP] - transformation of the element values from the normalized lowpass (NLP) to bandpass (BP)

syntfil[ElemsBP2] - transformation of the element values from the normalized lowpass (NLP) to bandpass (BP)

Calling sequence:

ElemsBP(blocks, R, f_p, fp)

ElemsBP2(blocks, R, fm, delta_fp)

Parameters:

blocks - table with NLP LC ladder description (see output from function DroppNLP)

R - value of terminating resistor [Ohm]

f_p - BP lower cutoff frequency [Hz]

fp - BP upper cutoff frequency [Hz]

fm - BP passband geometric cetre [Hz]

delta_fp - BP passband width [Hz]

Parameters f_p , fp , fm , delta_fp a R must be positive numbers, where f_p < fp .

Description:

This function returns table with BP filter description. The table has the same structure as input parameter blocks .

Index type is changed from LC_NLP_... to LC_BP_... .

Transformation changes inductor to serial connection of inductor and capacitor, and capacitor to parallel connection of inductor and capacitor.

The elements are transformed according to following rules:

, where

and

Info level:

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

infolevel[syntfil] =

2 - print BP type, terminating resistors and BP LC ladder branches on separate lines with description.

Example:

> with(syntfil):

Table with NLP filter description

> elems_nlp:=table([
1 = table([Z = 1/(s*C1), elements = {C1 = 1.}, orientation = shunt]),
2 = table([Z = s*L1, elements = {L1 = 2.}, orientation = direct]),
3 = table([Z = 1/(s*C1), elements = {C1 = 1.}, orientation = shunt]),
R2 = 1.00, R1 = 1.00, type = LC_NLP_common]):

Parameters for transformation

> R,f_p,fp:=100,1000,2000;

> elems_bp:=ElemsBP(elems_nlp,R,f_p,fp);

$elems_bp := TABLE([1 = TABLE([elements = {C1 = .1591549430e-5, L1 = .7957747156e-2}, orientation = shunt, Z = 1/(s*C1+1/(s*L1))]), 2 = TABLE([elements = {L1 = .3183098861e-1, C1 = .3978873576e-6}, orie...$
$elems_bp := TABLE([1 = TABLE([elements = {C1 = .1591549430e-5, L1 = .7957747156e-2}, orientation = shunt, Z = 1/(s*C1+1/(s*L1))]), 2 = TABLE([elements = {L1 = .3183098861e-1, C1 = .3978873576e-6}, orie...$
$elems_bp := TABLE([1 = TABLE([elements = {C1 = .1591549430e-5, L1 = .7957747156e-2}, orientation = shunt, Z = 1/(s*C1+1/(s*L1))]), 2 = TABLE([elements = {L1 = .3183098861e-1, C1 = .3978873576e-6}, orie...$
$elems_bp := TABLE([1 = TABLE([elements = {C1 = .1591549430e-5, L1 = .7957747156e-2}, orientation = shunt, Z = 1/(s*C1+1/(s*L1))]), 2 = TABLE([elements = {L1 = .3183098861e-1, C1 = .3978873576e-6}, orie...$
$elems_bp := TABLE([1 = TABLE([elements = {C1 = .1591549430e-5, L1 = .7957747156e-2}, orientation = shunt, Z = 1/(s*C1+1/(s*L1))]), 2 = TABLE([elements = {L1 = .3183098861e-1, C1 = .3978873576e-6}, orie...$

Compute transfer function from table with NLP filter description

> MakeH(elems_nlp);

Compute transfer function from table with BP filter description

> MakeH(elems_bp);

See also:

DroppNLP

ElemsLP, ElemsHP, ElemsBPm, ElemsBS, ElemsBSm

MakeH, MakeRealL