Electronic filter#BAW filters

BAW filters ( engl. bulk acoustic wave) are electronic filter with bandpass characteristic. They come in high-frequency technology, for example in mobile and wireless for use. The functioning is similar to that of a surface acoustic wave filter ( SAW filter ), but with the difference that the filters are BAW propagation of the acoustic waves in the substrate ( bulk).

Due to their superior electrical and physical properties of BAW filters are increasingly replacing the previously widespread SAW filter. In contrast to the SAW filters have BAW filter smaller sizes, a smaller insertion loss (< 0.5 dB), a better temperature coefficient ( about 20 ppm / Kelvin ) and are protected against electrostatic discharge ( ESD) sensitive. Another advantage is the lower cost of production as BAW filter based on the basis of CMOS technology and thus, no special materials are required for specific substrates.

BAW filters reach a quality factor in excess of 1000 and are available to frequencies of about 1 GHz to 20 GHz.