5. Comparison of acoustic filter technologies

The various acoustic filter technologies cover a very wide frequency range (1 MHz to a few GHz) and address a wide variety of specifications. In particular, relative bandwidths range from less than 0.1% to over 50%. Figure 56 shows the respective domains of the three technologies mentioned above: bulk wave filters (BAW), surface wave filters (SAW) and thin-film bulk wave filters (FBAR). SAW technology is by far the most versatile. To really cover all these fields, a wide variety of filter topologies and piezoelectric materials are required.