1. ACTIVE LEARNING ASSIGNMENT AVS(2151101)
SHAH BRIJESH SHAH RIYA

2. Introduction Elliptical, Butterworth, Chebyshev, Bessel, Cauer
Butterworth had a reputation for solving "impossible" mathematical problems
"An ideal electrical filter should not only completely reject the unwanted frequencies but should also have uniform sensitivity for the wanted frequencies".
Such an ideal filter cannot be achieved but Butterworth showed that successively closer approximations were obtained with increasing numbers of filter elements of the right values. At the time, filters generated substantial ripple in the passband, and the choice of component values was highly interactive. Butterworth showed that a low pass filter could be designed whose cutoff frequency was normalized to 1 radian per second and whose frequency response (gain)

3. What Are Diodes Made Out Of?Si +4
Silicon (Si) and Germanium (Ge) are the two most common single elements that are used to make Diodes. A compound that is commonly used is Gallium Arsenide (GaAs), especially in the case of LEDs because of it’s large bandgap.
Silicon and Germanium are both group 4 elements, meaning they have 4 valence electrons. Their structure allows them to grow in a shape called the diamond lattice.
Gallium is a group 3 element while Arsenide is a group 5 element. When put together as a compound, GaAs creates a zincblend lattice structure.
In both the diamond lattice and zincblend lattice, each atom shares its valence electrons with its four closest neighbors. This sharing of electrons is what ultimately allows diodes to be build. When dopants from groups 3 or 5 (in most cases) are added to Si, Ge or GaAs it changes the properties of the material so we are able to make the P- and N-type materials that become the diode.
The diagram above shows the 2D structure of the Si crystal. The light green lines represent the electronic bonds made when the valence electrons are shared. Each Si atom shares one electron with each of its four closest neighbors so that its valence band will have a full 8 electrons.

4. Filter Specification
Transmission specifications for a bandpass filter. The magnitude response of a filter that just meets specifications is also shown. Note that this particular filter has a monotonically decreasing transmission in the passband on both sides of the peak frequency.

5. Filter Specification Frequency-Selection function Passing Stopping
Specification of the transmission characteristics of a low-pass filter. The magnitude response of a filter that just meets specifications is also shown.
Filter Specification
Frequency-Selection function
Passing
Stopping
Pass-Band
Low-Pass
High-Pass
Band-Pass
Band-Stop
Band-Reject
Summary – Low-pass specs
-the passband edge, wp
-the maximum allowed variation in passband, Amax
-the stopband edge, ws
-the minimum required stopband attenuation, Amin
Passband ripple
Ripple bandwidth

6. Butterworth Filters
The magnitude response of a Butterworth filter.

7. Butterworth filter calculation for frequency response
As the Butterworth filter is maximally flat, this means that it is designed so that at zero frequency, the first 2n-1 derivatives for the power function with respect to frequency are zero.
Thus it is possible to derive the formula for the Butterworth filter frequency response:
Where:    f = frequency at which calculation is made    fo = the cut-off frequency, i.e. half power or -3dB frequency    Vin = input voltage    Vout = output voltage    n = number of elements in the filter

8. Frist orde law pass butter worth filter
Butterworth also showed that his basic low-pass filter could be modified to give low-pass, high-pass, band-pass and band-stop functionality.
Frist orde law pass butter worth filter
Fig;a circuit diagram
Fig;b frequency response

9. Frist order high pass butter worth filter
Fig;a circuit diagram
Fig;b frequency response

10. 2nd order law pass butterworth filter
Fig;a circuit diagram
Fig;b frequency response

11. 2nd order high pass butter worth filter
Fig;a circuit diagram
Fig;b frequency response

12. Ideal Frequency Response for a Butterworth Filter
Note that the higher the Butterworth filter order, the higher the number of cascaded stages there are within the filter design, and the closer the filter becomes to the ideal “brick wall” response.
In practice however, Butterworth’s ideal frequency response is unattainable as it produces excessive passband ripple.
Note that the higher the Butterworth filter order, the higher the number of cascaded stages there are within the filter design, and the closer the filter becomes to the ideal “brick wall” response.
In practice however, Butterworth’s ideal frequency response is unattainable as it produces excessive passband ripple.

13. Refrances;
Refrances book . Ramakant Gayakwad 8th ,edotion,

14. THANK YOU