The SKY78191-21 SkyOne® Multimode Multiband Tx-Rx Front- End Module (FEM) supports 2G / 3G / 4G mobile devices and operates efficiently in 3G/4G modes. The FEM consists of a lowband 3G/4G PA block, low- and high-band 2G PA blocks, a silicon controller containing the MIPI RFFE interface, RF band switches, antenna switches, a bi-directional coupler, and integrated filters for Bands 8, 12, 20 and 26. Extremely low leakage current maximizes device standby time.

The IC die and passive components are mounted on a multi-layer laminate substrate. The assembly encapsulated in a 7.6 mm x 6.0 mm x 0.75 mm, 56-pad MCM, SMT plastic package allows a highly manufacturable, low cost solution.

The SKY78191-21 FEM is optimized for LTE Advanced which utilizes Carrier Aggregation for higher data rates. The combined filtering, RF matching, and TRx switching internal to the FEM optimizes performance for popular Downlink (DL) CA band combinations, all in a compact and low cost solution. The FEM contains necessary components between the antenna and RFIC transceiver and is optimized to provide superior Rx sensitivity and Tx efficiency.

Selecting the linear-GMSK operation standard disables VRAMP input, so all PA biasing depends only on MIPI mode selection. The transmitted envelope is then a linear function of RF input.

Selecting VRAMP-enabled operation, the PA controller provides VRAMP control of the GMSK envelope and reduces sensitivity to input drive, temperature, power supply, and process variations. Skyworks’ Finger-Based Integrated Power Amplifier Control (FB-iPAC) minimizes output power variation into mismatch.

In EDGE linear mode, VRAMP voltage and MIPI-based bias settings jointly optimize PA linearity and efficiency.

Exceptional RF coexistence planning and system techniques are employed to minimize Rx de-sensitizing ("de-sense").