SAW general principle of its work, it is a transversal filter. SAWF the general structure of Figure 1Shown. It is mainly by the piezoelectric substrate, interdigital structure of transmitting and receiving transducers, as well as sound-absorbing material, etc
Figure 1 The general structure of surface acoustic
wave devices of the diagram
The principle is to use a major role in the piezoelectric properties of piezoelectric material, the use of input and output wave transducer to the input signals into mechanical energy, processed, and then mechanical energy into electrical signals, so as to achieve filtering unnecessary signals and Miscellaneous signals, improve signal reception quality objective.
SAWF technical indicators include: frequency range, the relative bandwidth, insertion loss, band fluctuations, return loss, band rejection, such as temperature range.
SAW filter frequency and scope of application
of the relative bandwidth