Apple apparently will replace current surface acoustic wave (SAW) RF filters with film bulk acoustic resonators (FBARs). Past iPhone models, including the Apple iPhone 4S, use the SAW filter and no change was expected in the next version of the phone. Instead, Apple is looking to use the advanced FBARs thanks to improvements in its manufacturing techniques that has cut the size and increased the efficiency of the product enough that it can be used inside a smartphone.
A strong sign that Apple is going with FBARs over SAW is the selection of Avago Technologies as a RF filter supplier. The company has recently spent tens of millions of dollars into adding capacity to its FBAR production, possibly in advance of receiving huge orders from Apple. Most importantly, Avago believes that it can shrink the size of the filter without putting a dent in performance which could expand its usage to more bands than it previously could be used for. If it does supply the FBARs to filter two 3G bands, Avago would have $3 of parts in the new Apple iPhone, up from $2.25 in the current model.