Second-Generation Front End Modules Support Carrier Aggregation

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Carrier aggregation (CA) allows mobile service providers to combine spectrum and increase data rate throughput by utilizing two or more bands simultaneously, thereby giving consumers an enriched data experience regardless of location. To meet the demands for smartphones, tablets and datacards requiring wider bandwidths being enabled by carrier aggregation, Skyworks has developed the SkyOneTM family of fully optimized, scalable devices that integrate all of the high performance RF and analog content between the transceiver and antenna into what is claimed to be the industry’s smallest footprint. They also provide excellent linearity and power added efficiency for smart RF integration.

The newest front end solutions – the second-generation SkyOne platforms – cover more frequency bands, integrate up to seven duplexers, support carrier aggregation and provide standardized inputs for all leading chipsets that are MIPI® RFFE compatible and address both transmit (Tx) and receive (Rx) switching paths. Skyworks’ carrier aggregation switching solutions, which are compliant to tier-one, carrier-driven specifications, are based on silicon-on-insulator wafer process technologies and are available in many different configurations.


SkyOne, illustrated in Figure 1, is an 8 × 9 × 0.95 mm module with up to seven duplexers and a dual-pole, 19 throw antenna switch module (ASM) for models supporting carrier aggregation and single pole, 16 throw ASMs for models without a CA requirement. There are multiple variations available depending on regional frequency requirements: the SKY78021, SKY78022, SKY78025 and SKY78026.

Figure 1

Figure 1 SkyOne™ block diagram.

SKY78021 is a hybrid, multimode, multiband (MMMB) front end module that supports 2.5G, 3G/4G and CDMA handsets and all standard carrier aggregation frequency band combinations through its integrated dual pole 19 throw switch. This module operates efficiently in EDGE, GPRS, GSM, HSPA, LTE and WCDMA modes.

SKY78022, SKY78025 and SKY78026 are MMMB FEMs supporting 2.5G, 3G/4G, CDMA and TDD-LTE handsets and operate efficiently in EDGE, GPRS, GSM, HSPA, LTE, TDD-LTE and WCDMA modes. These modules integrate single pole, 16 throw switches with internal IEC protection.

All four SkyOne FEMs consist of a GSM800/EGSM900 PA block, a DCS1800/PCS1900 PA block, separate WCDMA blocks operating in the low and high bands, a logic control block for multiple power control levels, and band enable functions in both cellular and UMTS. RF I/O ports, internally matched to 50 Ω, minimize the need for external components, while extremely low leakage current maximizes handset standby time. The InGaP/GaAs die and passive components are mounted on a multi-layer laminate substrate and the assembly is encapsulated in plastic overmold.

Compact Architecture

For GSM/EDGE the FEMs’ new compact architecture supports the GSM850, EGSM900, DCS1800 and PCS1900 bands, as well as 2.5G Class 12 Enhanced General Packet Radio Service (EGPRS) multi-slot operation and EDGE linear modulation. WCDMA enhanced architecture supports WCDMA/High-Speed Downlink Packet Access (HSDPA) and High-Speed Uplink Packet Access (HSUPA) modulations, covering multiple bands for 3GPP, and operating at different power modes. The modules are fully controllable via a MiPi serial interface.

The SkyOne FEMs meet spectral linearity requirements of LTE modulation with QPSK/16QAM up to 20 MHz bandwidth, including various resource block allocations, with good power-added efficiency. They also meet the spectral linearity requirements of CDMA 2K and EVDO Release A modulation with good power-added efficiency.

The Receiver

For the receiver section GPS and LB/HB WiFi coexistence are designed-in for exceptional support to maintain all radio performance, even in user scenarios of simultaneous use. Optimized low insertion loss Rx paths, matching circuits, and well-grounded guard traces (high Tx-Rx isolation) inside the modules mitigate de-sense problems and enhance sensitivity performance.

The SKY78021 integrated duplexers, Rx SAWs, and a split LB (SP8T)/HB (SP10T) SOI switch support simultaneous downlink carrier aggregation for additional Rx data rate, and provides 2G/3G/4G Rx paths from antenna to LNA port of RFIC. Carrier aggregation requirements for noise and harmonics are designed-in for best de-sense performance. Additionally, the SKY78021 provides four LB and five HB ports. With the SKY78022, SKY78025 and SKY78026, the integrated duplexers, Rx SAWs, and SP16T SOI switch provide 2G/3G/4G Rx paths from the antenna to LNA port of RFIC and all modules provide eight auxiliary ports.

Skyworks has incorporated breakthrough RF switching technology in its newest devices that are enabling early adopters to implement carrier aggregation solutions. SkyOne devices deliver excellent performance, are highly customizable and scalable as well as compatible with all leading chipsets solutions.

Skyworks Solutions Inc.,
Woburn, MA
(781) 376-3000,

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