Advantages of FBAR Filter | disadvantages of FBAR Filter
This page covers advantages and disadvantages of FBAR Filter. It mentions FBAR Filter advantages or benefits and FBAR Filter disadvantages or drawbacks.
What is FBAR Filter?
• FBAR is the short form of Film Bulk Acoustic Resonator.
• FBAR filters are developed using thin film semiconductor process. This process is used to build a Metal-Aluminium Nitride-Metal Sandwich in air.
• They are form of BAW (Bulk Acoustic Wave) filter with superior performance compare to SAW filters.
• The other devices as per FBAR technology include duplexers, multiplexers, resonators etc.
• The figure-1 depicts FBAR (Film Bulk Acoustic Resonator)
and BAW SMR (Bulk Acoustic Wave Solidly Mounted Resonator) type filter designs.
For FBAR, the air/crystal interface on both faces of the resonator ensures that the
main mode of interest (i.e. acoustic energy) is appropriately trapped.
• The figure-2 depicts attenuation versus frequency curve of FBAR filter and SAW filter.
• Refer difference between BAW filter and SAW filter >>.
Benefits or advantages of FBAR Filter
Following are the benefits or advantages of FBAR Filter:
➨It offers lower insertion loss. As a result it consumes less current. This leads to long battery life and fewer dropped calls.
➨It offers steeper filtering. Hence better coexistence with adjacent bands can be achieved.
➨It offers better out-of-band rejection. Hence multi-band capability can be achieved.
➨It offers ultra small size devices. Hence it can be fit easily with other semiconductor chips.
➨FBAR filters operate reliably in high power and worst temperature conditions.
Drawbacks or disadvantages of FBAR Filter
Following are the drawbacks or disadvantages of FBAR Filter:
➨Thermal path for heat generated in the device is crucial in the design of FBAR and BAW-SMR filters. In BAW-SMR type, heat has conduction path into the substrate from which heat can be spread. However in FBAR type, there is air gap on each side of the resonator. Hence in FBAR designs, thermal conduction path is weaker.