Advantages of BAW filter | disadvantages of BAW filter
This page covers advantages and disadvantages of BAW filter and its basics. It mentions benefits or advantages of BAW filter and drawbacks or disadvantages of BAW filter.
What is BAW filter?
BAW stands for Bulk Acoustic Film technology. BAW filter stores the signal in acoustic resonators unlike conventional filter. BAW filters operate in frequency range from 1.5 GHz to 6 GHz.
BAW filters are designed as per two general architectures viz. SMRs (Solidly mounted resonators) and FBARs (Film Bulk Acostic Resonators). The figure depicts basic structure of BAW filter. As shown,in BAW filter, an electric field excites acoustic wave which travels in vertical direction through the body of piezoelectric substrate. Here resonant frequency is determined by thickness of piezoelectric layer.
To form BAW filter or resonator different types of metal films are deposited on top/bottom of piezoelectric materials. These include aluminum for lower power level and tungsten for higher power level.
Benefits or advantages of BAW filter
Following are the benefits or advantages of BAW filter compare to SAW filters operating at
the same higher frequencies:
➨BAW technology yields approx. four times more parts per wafer. Hence it offers more component density compare to SAW filter.
➨It offers lower loss.
➨It offers higher Q.
➨It offers higher power handling capacity.
➨It offers greater selectivity.
➨It offers less temperature variation than SAW filter devices.
Drawbacks or disadvantages of BAW filter
Following are the drawbacks or disadvantages of BAW filter:
➨BAW filters are more expensive than SAW filters to manufacture.
➨It requires ten times more processing steps than SAW filters i.e. BAW filter needs more complex methods to fabricate than SAW filter.
➨The performance of BAW filter degrades at higher frequencies. Hence other filter types are being used for filter designs greater than 6 GHz and in mmwave bands.
Also refer advantages and disadvantages of SAW filter >> type.