E E 2 7 5 Lab October 16, 2007

Lab 7a. Filter Design in MATLAB

Do the following:

1. In MATLAB type archref and see the various structures for lters. (You need SGO1 and SGO2 softwarefor this. It is Archive.zip under Software in EE-289 Labs).

2. Invoke fdatool in MATLAB

3. Design Lowpass, IIR, Butterworth, Order 20, Fs=48000 hz, Fc=10800 lter, Structure: Direct Form 1.(Edit Covert to Single Section) Also can use Edit Convert Structure. Look at Magnitude andPhase Response (Analysis Magnitude and Phase Responses).

4. Covert to Second-Order-Sections. Look at Magnitude and Phase response. Note the dierence.

5. Look at Filter Coecients (under Analysis) for single and second-order sections.

6. Look at Round-o Noise Power Spectrum (under Analysis) for single and second order sections.

7. Convert to dierent structures under Edit and observe frequency behavior.

8. Realize Model (push the Realize Model icon on the left hand side) for any one realization and notethat you get a model ready for SIMULINK.

9. When looking at various lter structures, determine the transfer function of Direct Form I and DirectForm II.