Helios™ DigRF Subsystem
Complete
two-chip, Helios DigRF Subsystem for quad-band (GSM850,
EGSM900, DCS1800, PCS1900) cellular handsets
Skyworks Helios DigRF EDGE RF Subsystem combines a direct conversion transceiver, PA, and a T/R switch into a dual-chip radio solution that saves significant space, cost, and design cycle time while providing world-class GSM/GPRS/EDGE performance.
At the heart of the radio subsystem is Skyworks advanced Polar Loop™ transmit modulation architecture, which enables the radio to transmit both constant and non-constant envelope signals through the same transmit path to minimize the number of external components required to build a mobile handset. This significantly reduces the complexity, size, cost, and power requirements of next-generation EDGE platforms.
The Helios DigRF Subsystem features:
- Direct connection to Single Cell Lithium-ion Battery
- Polar Loop transmit modulation architecture
- Integrated noise filtering; no pre-PA filters required
- Closed loop phase and amplitude modulation (GMSK,π/8 8-PSK) via control of non-linear GSM PA
- PA inside control loop provides excellent EVM and phase error performance with up to 6:1 VSWR without external isolator
- Compliant with V1.12 of the DigRF standard
The Helios DigRF Subsystem consists of:
- SKY74200 RF Transceiver – Direct conversion transceiver eliminates the need for special baseband processing requirements and external image reject/IF filtering with DigRF interface.
- SKY77520 T/R Front End Module – A highly intergrated Front End Module with separate GSM850/EGSM900 and DCS1800/PCS1900 PA blocks, a PAC block, impedance-matching, an integrated coupler, a PHEMT switch and a diplexer for excellent EVM and phase error performance.