The SKY68018-11 from Skyworks is an LTE Multi-band Multi-chip RF Front-End (RFFE) module that is designed for NB-IoT applications. It consists of a broadband power amplifier with a bias controller, Tx low-pass harmonic filter, SP6T antenna switch, and MIPI RFFE controller. The FEM supports half-duplex system transceiver platforms and has four additional Tx/Rx ports that offer greater flexibility for more bands on the Tx or Rx path.
The included power amplifier is designed for high efficiency while simultaneously meeting 3GPP ACLR and emissions mask specifications for NB-IoT applications. Its PAE is optimized for both Class 4 LTE output power (+20 dBm) and Class 3 LTE output power (+23 dBm). The low pass filter is implemented to reject the power amplifier and transceiver harmonics while at the same time minimizing loss for an optimized transmit current consumption.
The FEM can be controlled by a single MIPI interface that is used to drive the power amplifier in various optimized bias modes and provide band selection for controlling the antenna switch Tx and Rx. It has a smart biasing feature that allows easy power control through the MIPI RFFE interface by programming a reduced bias current for lower gain states. The key advantages of smart biasing are - saving current consumption during lower output power operation, easy programming of fixed-gain steps through the MIPI interface, and reducing the required output dynamic range of the transceiver.
The SKY68018-11 is available in a module that measures 4 x 5 x 0.85 mm and is ideal for applications such as cellular IoT modem devices targeting low-power wide-area network (LPWAN) - 4G LTE, dedicated LTE half-duplex operation (HD-FDD) for NB-IoT and designed to meet 3GPP Rel-13 specifications. It supports LTE low-band B5/B8/B12/B13/B17/B18/B19/B20/B26/B28 and mid-band B1/B2/B3/B4/B25/B39/B66 frequencies.
