• Description:
  • Info level:
• Example:
• See also:

      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:

• These functions return table with BP filter description. The table has the same structure as input parameter blocks .
• Index type  is changed from LC_NLP_...  to LC_BPm_...  .  
• When transforming NLP without resonant circuits, the functions return the same structure of filter as functions ElemsBP, ElemsBP2.
• The modification consists in replacing serial resonant circuit by parallel connection of two serial resonant circuits and in replacing parallel resonant circuit by serial connection of two parallel resonant circuits. This modified LC bandpass is more favourable than standard LC bandpass in certain cases.
• Otherwise transformation changes inductor to serial connection of inductor and capacitor, and capacitor to parallel connection of inductor and capacitor.
• Branch elements without resonant circuits are transformed according to following rules: , , , , ,
• Serial resonant circuit is transformed according to following rules:
  , , , .
• Parallel resonant circuit is transformed according to following rules:
  , , , .
• 
• ,

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):

Compute Cauer approximation

>	G,Phi,zeros:=Cauer(3,2,3,s);

Compute the element values of NLP LC ladder

>	elems_nlp:=DroppNLP(common,1,rear,PI,G,Phi,zeros);

Parameters for transformation

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

Standard transformation

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

Modified transformation

>	elems_bpm:=ElemsBPm(elems_nlp,R,f_p,fp);

Compute transfer function from table with BP filter description

>	MakeH(elems_bp);

Compute transfer function from table with modified BP filter description

>	MakeH(elems_bpm);

See also:

DroppNLP

ElemsLP, ElemsHP, ElemsBP, ElemsBS, ElemsBSm

MakeH, MakeRealL