Surface Acoustic Wave (SAW) Filter Experiment

Objective

The objective of this experiment is to explore the functionality of a Surface Acoustic Wave (SAW) filter and its application in filtering unwanted frequencies in signal processing. The experiment will demonstrate how SAW filters work and their importance in RF applications.

Components Required

• 1 x Surface Acoustic Wave (SAW) Filter (e.g., 2.4 GHz SAW filter)
• 1 x Signal Generator
• 1 x Oscilloscope
• 1 x Power Supply (if required for the signal generator)
• Connecting Wires
• Breadboard (optional)

Theory

A Surface Acoustic Wave (SAW) filter uses acoustic waves traveling along the surface of a piezoelectric material to filter signals based on their frequency. The filter selectively allows certain frequencies to pass while attenuating others. SAW filters are compact and efficient, making them popular in various RF applications, such as mobile phones, televisions, and radios.

Key characteristics of SAW filters include:

• Center Frequency: The frequency at which the filter operates most effectively.
• Bandwidth: The range of frequencies that the filter can effectively pass.
• Insertion Loss: The amount of signal loss that occurs when the signal passes through the filter.

Circuit Diagram

Experimental Setup

1. Connect the output of the signal generator to the input of the SAW filter.

2. Connect the output of the SAW filter to the input of the oscilloscope.

3. Ensure that all components are properly grounded as required.

Procedure

1. Set up the circuit according to the circuit diagram.
2. Configure the signal generator to produce a known frequency signal (e.g., 2.4 GHz sine wave).
3. Observe the input signal on the oscilloscope and record its amplitude and waveform.
4. Observe the output signal from the SAW filter and compare its characteristics to the input signal.
5. Vary the input frequency and note the behavior of the output signal as it approaches and moves away from the filter's center frequency.
6. Record the filter's insertion loss and bandwidth based on your observations.

Results and Observations

Record the amplitude, waveform, and any discrepancies between the input and output signals at various frequencies. Note how well the SAW filter performs in filtering specific frequencies.

Conclusion

This experiment demonstrates the functionality of a Surface Acoustic Wave (SAW) filter in filtering signals. The SAW filter effectively transmits desired frequencies while attenuating unwanted signals, showcasing its importance in RF communication applications.