RC Band Pass Filter (Malayalam) Analog Communication Lab
AIM
To set up BAND pass filter (BPF) to find out the cut off frequency.
EQUIPMENTS/COMPONENTS
Sl.No Name & Specification. Quantity required.
1 CRO/DSO 1No.
2 Function generator 1No.
3 Capacitors 0.1uF 2 No
4 Resistors- 1.5 kΩ, 560 Ω 1 Nos.
PRINCIPLE
Filter is a circuit that can be designed to modify, reshape or reject all unwanted
frequencies of an electrical signal and accept or pass only wanted signals. Passive Filters are
made up of passive components such as resistors, capacitors and inductors and have no
amplifying elements (transistors, op-amps, etc) so have no signal gain, therefore their output
level is always less than the input.
Filters are so named according to the frequency range of signals that they allow to pass
through them, while blocking or attenuating the rest. The most commonly used filter designs are
The Band Pass Filter (BPF).
The band pass filter allows signals falling within a certain frequency band while
blocking both the lower and higher frequencies on either side of this frequency band
PROCEDURE
1. Check all the components, equipments and signal probes
2. Set up the connections as per the circuit diagram
3. Apply 1V pp/100Hz sine wave to circuit.
4. Observe the output waveform in the CRO and measure amplitude.
5. Vary the frequency of input signal up to 5 kHz with uniform increment of 200Hz.
6. Plot the frequency response curve.
F = 1/(2πRC)
Let fc=1KHz
R1=1.5K, R2=560Ω, C1=0.1μF, C2=0.1μ F
OBSERVATIONS
Vin=1 V pp
Sl. No Frequency (Hz) V out(v) Gain (Vout/Vin) Gain in dB 20 log(Vout/Vin)
