Solutions for Reconfigurable Mobile Device RF Front-ends

Tunable RF elements are now in widespread use within mobile handsets to improve performance, compensate for environmental influences, shrink antenna volumes and shorten design cycles. Many companies are now bringing tuner products to the market utilizing a range of core technologies. As a new component in the RF designer's toolkit, the impact of tunable components on the design and implementation of modern radios is still rapidly evolving. The performance, size and cost requirements for the tunable elements depend strongly on details of the application. The most critical challenge facing the RF front end of modern radios arises from the rapidly expanding frequency bands of operation for 4G and 5G systems around the world. In many cases, there is a multiplicity of bands even within individual countries. Each frequency band and mode typically requires customized filtering to handle unique interference challenges. The complexity following the present design approach scales super-linearly due to the interactions between the multiple hardware chains, particularly with regards to matching and isolation. The increase in hardware also applies strong upward pressure on system area and cost while negatively impacting performance, particularly overall efficiency. We present details on development toward a fully tunable system targeted to replace the large quantity of fixed elements currently required with a scalable and compact global solution.