Simplifying and Accelerating the Deployment of Carrier Aggregation

Multiplexer 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.

How Do Duplexer and Multiplexer System Architectures Differ?

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 switch-duplexer approach:

Switch-Multiplexer Approach

  • Designed with complementary matching so
    filters can coexist in one package
  • Less board area required
  • Lower insertion loss/better link budget
Switch-Plexer Approach

  • 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 next-generation products.

Qorvo® Multiplexers

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.

  • QM25005: 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.
  • QM25001, QM25011, 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 Filters webpages for the latest information how Qorvo is advancing multiplexers and CA technology.

Addressing Carrier Aggregation Challenges Using Multiplexer Solutions

Learn how multiplexers provide an elegant solution – and in many cases, the only practical solution – for CA combinations that use closely spaced bands.

Read the Whitepaper >>

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