SAW duplexers

Epcos is developing the miniaturisation of UMTS duplexers with filter components for W-CDMA bands I and V in case size 2016 that have a footprint of 2.0 x 1.6 mm² and height of 0.45 mm.

The duplexers allow the integration of more bands in mobile phones whose size remains unchanged.

Co-banding is required for mobile phones and data cards operating in the networks of all UMTS providers worldwide and manufacturers are already developing mobile phones that operate in up to five different W-CDMA bands.

As transmit and receive frequencies lie very close to each other within a band, the filters must have good electrical parameters, such as high edge steepness.

The first duplexers of case size 2016 were implemented completely on a SAW basis. In future, the SAW filters will be complemented by BAW filters, which have better performance at certain frequencies.