solutions help simplify and accelerate adoption of carrier aggregation (CA) in 4G
LTE devices. These compact multiplexer devices deliver up to 60% space savings and cover
primary band combinations such as Bands 1 and 3 used in CA deployments.
But First… What Are Multiplexers?
A multiplexer is a
device that separates signals from a common input to multiple outputs, sorting the output ports
according to specific band frequencies. As shown in Figure 1 below, a multiplexer takes the
place of two duplexers, reducing size and complexity for the system engineer. However, this
introduces challenges for the multiplexer designer. The multiplexer designer must painstakingly
match individual band duplexer filters, meeting stringent specifications for isolation, cross
isolation, attenuation and insertion loss.
Figure 1. Duplexer Versus Multiplexer
How Do Duplexer and Multiplexer System Architectures
Multiplexers used in RF
front-end architectures enable CA, which helps increase data speeds for mobile device
networks. They also simplify the design for engineers. Some architectures using multiplexers
require no switch (right side of Figure 2) rather than a duplexer design using two single-throw
switches (left side of Figure 2).
Figure 2. System Approach: 2 Duplexers to 1 Multiplexer
The switch-multiplexer combination also gives the following benefits over the
- Designed with complementary matching so
filters can coexist in one package
- Less board area required
- Lower insertion loss/better link budget
- Phase shifters needed, programmability/tradeoffs
- Takes up more board area
- Increased link budget compared to switch multiplexer approach
In short, multiplexer solutions simplify design, reduce product footprint, conserve power
and improve overall system performance. This gives mobile device design engineers the ability
to offer customers a unique product in addition to accelerating their delivery of
Qorvo multiplexers meet global regional device requirements integrating multiple SAW and BAW
filters. They additionally cover the primary band combinations used in CA deployments, such as
Bands 1+3 and Bands 39+41.
Qorvo's QM25005 multiplexer features LowDrift™ transmit and receive filters for
FDD-LTE Bands 1 and 3 in a highly compact 3.0 x 2.0 mm form factor. Enabling downlink
CA, the QM25005 is qualified with leading LTE chipsets and performance-optimized to
deliver best-in-class insertion loss and high isolation, resulting in improved receive
sensitivity and coverage.
QM25012: These three Qorvo multiplexers feature LowDrift™ BAW filter
technology for TDD-LTE Bands 39 and 41, each developed in partnership with leading
chipset suppliers. With a compact 2.5 x 2.0 mm footprint, the QM25001 is designed for
global smartphones supporting the full Band 41 spectrum for worldwide use. The QM25011
and QM25012 are designed for China domestic smartphones and optimized for China's Band
41 narrowband allocation. The QM25011 includes primary transmit and receive filters in
a 1.7 x 1.3 mm package, while the complementary QM25012 provides diversity receive
filters in an even smaller 1.5 x 1.1 mm footprint. Both products provide at least a 60%
space savings over discrete components.
Visit our Carrier
Aggregation and Advanced Filter Solutions webpages for
the latest information how Qorvo is advancing multiplexers and CA technology.