Executive Summary
Mobile network operators worldwide are deploying carrier aggregation (CA), which enables them to provide faster data
services by bonding two or more blocks of spectrum into a wider channel. With CA, mobile devices communicate on
multiple LTE bands simultaneously, but this creates a challenge: how to avoid interference between the bands
(cross-isolation) while minimizing insertion loss to maintain good reception and battery life. Multiplexers provide an
elegant solution – and in many cases, the only practical solution – for CA combinations that use closely spaced bands.
Multiplexers integrate all the filters required for multiple aggregated bands, providing isolation between and within
bands while allowing them to connect to the antenna at the same time. Carefully matched bulk acoustic wave (BAW)
and temperature compensated-surface acoustic wave (TC-SAW) filters are essential to meet system requirements.
Multiplexers will become increasingly important as operators aggregate three or more bands. Additional benefits of
multiplexers include space savings, simplified design and reduced cost.