The demand for bandwidth in cellphones is driving the industry toward complex RF front-ends that rely heavily on acoustic filters. The main purpose of this talk is to give an overview of filter technologies (SAW, BAW, temperature-compensated SAW), some basic acoustic design techniques (ladder filter, duplexers and multiplexers) and a sense of what to look for when working with filters. We will try to shed some light on the key specifications and trade-offs for RF filters and how they affect the RF front-end of a phone.