A surface acoustic wave (SAW) structure typically consists of a piezoelectric substrate, such as quartz or lithium niobate, with interdigitated metal electrodes deposited on its surface. These electrodes are arranged in a specific pattern to generate and manipulate surface acoustic waves. When an electrical signal is applied to these electrodes, it creates a mechanical vibration in the piezoelectric material, which propagates along the surface like a saw. The structure may also include reflectors or transducers to improve wave propagation and control saw characteristics, such as frequency and amplitude.
To make a surface acoustic wave (SAW), specialized manufacturing processes are used to make the piezoelectric substrate and deposit the interdigitated electrodes. Initially, a high purity piezoelectric material such as quartz is cut into precise dimensions to support the desired frequency range of the saw. Thin-film deposition techniques, such as sputtering or evaporation, are then used to deposit metal electrodes on the substrate surface in a pattern that facilitates saw generation and manipulation. The substrate can undergo additional processing steps, such as photolithography and etching, to define the electrode pattern and optimize saw performance.
A surface acoustic wave (SAW) filter is a type of acoustic wave device that uses SAW propagation to filter and manipulate electrical signals. It consists of a piezoelectric substrate with interdigitated electrodes designed to transmit or reflect specific frequencies of acoustic waves. When an electrical signal is applied to the input electrodes of the saw filter, it generates a surface acoustic wave that propagates along the substrate. The acoustic wave interacts with the electrodes and substrate structure to selectively attenuate or pass certain frequencies of the input signal, effectively filtering out unwanted frequencies. SAW filters are used in various applications such as wireless communication, signal processing and sensor systems due to their compact size, low power consumption and ability to achieve high selectivity and performance .