filters

LOW PASS FILTER
HIGH PASS FILTER
BAND PASS FILTER
BAND REJECT FILTER

1. LOW PASS FILTER HIGH PASS FILTER BAND PASS FILTER BAND REJECT FILTER By Anand Kumar Roll no: 2012-70

2. Filters(Definitions) and their applications As name suggest it filters come contents of input signal and give desired output signal. In general electrical and electronics engineering sometimes it is desirable to have circuits capable of selectively filtering of one frequency or range of frequencies out of a mix of different frequencies in a circuit. A circuit designed to perform this frequency selection is called a filter circuit , or simply a filter best example is the FM or frequency modulation that we use in our daily life

3. The filter circuits can be made by two components :- 1. PASSIVE 2. ACTIVE

4. BANDPASS FILTER LOWPASS FILTER HIGHPASS FILTER TYPES OF FILTER ☺ BAND STOP FILTER

5. LOW PASS FILTER

6. An ideal low-pass filter is a circuit which passes low-frequency signals and block high-frequency signals. There are three basic kinds of circuits capable of accomplishing this objective, and many variations of each one:- First-order filter Second-order filter Higher-order filter Active electronic realization

7. CIRCUIT DIAGRAM

8. CIRCUIT DIAGRAM An RLC circuit is an electrical circuit consisting of a resistor, an inductor, and a capacitor, connected in series or in parallel. A second-order filter attenuates higher frequencies more steeply. The Bode plot for this type of filter resembles that of a first-order filter, except that it falls off more quickly. Second order low pass filter(RLC filter)

9. CIRCUIT DIAGRAM Higher order passive filters WE CAN USE MORE CASCADED RC ALONG WITH SERIES

10. Active low pass filter(with opamp ) March 29, 2017 Another type of electrical circuit is an active low-pass filter. In the op-amp circuit shown in the figure, the cutoff frequency (in hertz) is defined as: or equivalently (in radians per second): The gain in the pass band is − R 2 / R 1

11. PASS HIGH FILTERS 2

12. CIRCUIT DIAGRAM High pass filters using LC components, i.e. inductors and capacitors are arranged in ether a pi or T network. As suggested by its name, the pi network has one series component, and either side of it there is a component to ground. Similarly the T network high pass filter has one component to ground and either side there is a series in line component. In the case of a high pass filter the series component or components are capacitors whereas the components to ground are inductors. In this way these filters pass the high frequency signals, and reject the low frequency signals. These filters may be used in applications where there are unwanted signals in a band of frequencies below the cut-off frequency and it is necessary to pass the wanted signals in a band above the cut-off frequency of the filter. HIGH pass filter(RLC filter)

13. Active HIGH pass filter(with op-amp) March 29, 2017 Figure shows an active electronic implementation of a first-order high-pass filter using an opamp . In this case,the filter has a passband gain of - R 2 / R 1 and has a cutoff frequency of Because this filter is active, it may have nonunity passband gain. That is, high-frequency signals are inverted and amplified by R 2 / R 1 .

14. FILTER BANDPASS 3

15. Band pass filter A band-pass filter is a device that passes frequencies within a certain range and rejects (attenuates) frequencies outside that range. These filters can also be created by combining a low-pass filter with a high-pass filter. The bandwidth of the filter is simply the difference between the upper and lower cutoff frequencies. Q factor:- A band-pass filter can be characterised by its Q factor. The Q-factor is the inverse of the fractional bandwidth. A high-Q filter will have a narrow passband and a low-Q filter will have a wide passband. These are respectively referred to as narrow-band and wide-band filters. March 29, 2017

16. Band pass with LC components Like the high pass filters and the low pass filters, there are two topologies that are used for these filters, namely the Pi and the T configurations. Rather than having a single element in each leg of the filter as in the case of the low pass and high pass filters, the band pass filter has a resonant circuit in each leg. These resonant circuits are either series or parallel tuned LC circuits.

17. Main terms March 29, 2017 GAIN SLOPE BANDWITH Frequency response f H = High frequency f L = Low frequency

18. Basic RC based band pass filter March 29, 2017

19. Active Band pass filter March 29, 2017

20. Active bandpass filter with stages March 29, 2017

21. BAND STOP OR BAND REJECT FILTER 4

22. Band stop or band rejection filter In signal processing, a band-stop filter or band-rejection filter is a filter that passes most frequencies unaltered, but attenuates those in a specific range to very low levels. It is the opposite of a band-pass filter. A notch filter is a band-stop filter with a narrow stop band (high Q factor). March 29, 2017

23. band stop filter( WITH RC ) March 29, 2017

24. Active band stop filter March 29, 2017 These are classified as: Wide band reject filters Narrow band reject filters (Notch filters). Wide band reject filters Narrow band reject filters (Notch filters).

25. REFRENCES My friends & teachers http://www.radio-electronics.com/ http://en.wikipedia.org/wiki/Band-stop_filter http://www.allaboutcircuits.com/vol_2/chpt_8/5.html http://www.circuitstoday.com/band-stop-filter

26. THANK YOU