High-Pass Filter for Signal Transmission Experiment

Objective

The objective of this experiment is to design and implement a high-pass filter (HPF) that allows high-frequency signals to pass while attenuating lower frequencies. This experiment will demonstrate the applications of high-pass filters in signal transmission and audio processing.

Components Required

• 1 x Resistor (R)
• 1 x Capacitor (C)
• 1 x Operational Amplifier (e.g., LM358)
• 1 x Signal Generator (e.g., function generator or audio player)
• 1 x Oscilloscope
• Connecting Wires
• Breadboard (optional)

Theory

A high-pass filter is designed to pass signals with a frequency higher than a certain cutoff frequency while attenuating signals with frequencies lower than the cutoff frequency. The cutoff frequency \( f_c \) can be calculated using the formula:

• Cutoff Frequency: \( f_c = \frac{1}{2 \pi R C} \)

This formula shows that the cutoff frequency is determined by the values of the resistor and capacitor used in the circuit.

Circuit Diagram

Experimental Setup

1. Connect the components according to the circuit diagram, ensuring all connections are secure.

2. Connect the signal generator to the input of the high-pass filter.

3. Connect the output of the high-pass filter to the input of the oscilloscope.

Procedure

1. Set up the circuit according to the circuit diagram.
2. Configure the signal generator to produce a sine wave or audio signal.
3. Observe the output signal on the oscilloscope and record its amplitude and waveform.
4. Vary the frequency of the input signal and note how the output signal changes as it approaches the cutoff frequency.
5. Record the output amplitude at various input frequencies, particularly around the cutoff frequency.
6. Determine the cutoff frequency based on your observations and calculations.

Results and Observations

Document the output signal amplitude and characteristics for different input frequencies. Note the frequency at which the output signal starts to attenuate significantly.

Conclusion

This experiment demonstrates the operation of a high-pass filter in signal transmission, allowing high-frequency signals to pass while attenuating lower frequencies. High-pass filters are commonly used in audio applications to eliminate low-frequency noise and improve the clarity of the transmitted signal.