Interstage filter cuts diodes from handset designs

Edited by the Electronicstalk editorial team Dec 17, 2003

A new high-performance SAW filter aims for applications in mobile phones and data cards operating in the PCS band with code division multiple access (CDMA).

A new high-performance SAW filter aims for applications in mobile phones and data cards operating in the PCS band with code division multiple access (CDMA).

Covering the entire PCS band, the B7759 interstage filter eliminates noise in the transmit path and significantly reduces crosstalk from the transmit to receive path.

Until now, these functions have been performed by SAW split-band filters, but a conventional split-band filter solution requires two diode switches and additional control logic that take up valuable board space and consume power.

Measuring only 2.0 x 2.5 x 0.74mm, the new SAW filter provides an efficient solution in terms of size as well as cost.

"Our B7759 requires up to 70% less space in the front end of a handset, saves energy and cuts component costs for filtering in the transmit path by as much as 50%", said Joachim Niestroj, Head of Mobile Communications in Epcos' SAW Components Division.

The CSSPlus packaging technology patented by Epcos and used in the B7759 sets a further milestone in miniaturisation.

The filter's small footprint and low insertion height make it ideal for integration into modules for the next generation of CDMA handsets and data cards.