Hi i'm looking for the theory i.e. formulas and so on in order to design this kind of filter



I would be grateful if you give me the name of this circuit and a tutorial or a reference where to find the description and the design procedure.

 

You can search on google as following keyword, maybe you can find the info you want.

keyword:
A Sallen-Key 3-Pole Butterworth Active Highpass Filter

 

Download the free FilterPro program from Texas Instrument.

 

Get a copy of

van Valkenburg,Analog Filter Design

 

FilterLab from Microchip is good and free.

 

This is a good Active Filter reference.