Complete Radio Subsystem for EDGE Mobile Platforms

US : Skyworks Solutions introduced a complete RF subsystem for E-GPRS (GSM/GPRS/EDGE) mobile handsets. Skyworks' RF chipset solution includes the company's leadership single-chip direct conversion transceiver, power amplifier (PA) module and a PA controller/modulator.

Skyworks' new subsystem utilizes the company's patent-pending Polar Loop™ transmit modulation technology which eliminates expensive components such as SAW filters, in order to save handset designers significant space, cost and design-cycle time with improved performance. This approach has the potential for improving PA efficiency in EDGE mode by up to 10 percent when compared to conventional architectures, resulting in improved talk times.

EDGE, or Enhanced Data Rates for GSM Evolution, is a wireless communications technology that allows consumers to use cellular handsets, PC cards, PDAs and other wireless devices to connect to the Internet at data rates up to four times faster than existing GSM and GPRS wireless devices.

"Skyworks continues to extend its leadership in RF subsystems and PAs, with a three-chip solution that enables customers to quickly enter the rapidly emerging market for EDGE-based wireless data services," said Mohy Abdelgany, vice president of RF Systems for Skyworks. "Our innovative Polar Loop modulation technique provides significant improvements in BOM reductions and power efficiency and will give designers a powerful solution for developing next-generation E-GPRS handsets."

Technical Details

Skyworks' complete radio subsystem includes all the necessary RF components for building state-of-the-art quad-band (850/900/1800/1900) handsets. At the heart of the solution is the company's advanced Polar Loop transmit modulation architecture. This unique approach enables the radio to transmit both constant as well as non-constant envelope signals through the same transmit path to minimize the number of external components required to build a mobile handset. In addition, the architecture significantly reduces the complexity, size, cost and power requirements of next-generation EDGE platforms.

Skyworks' Polar Loop technology leverages saturation-mode PA technology, the industry's dominant approach for GSM terminals, to maximize power added efficiency (PAE) in EDGE modulation (8-Phase Shift Keying). This is done in an extremely robust closed-loop system. The three-chip solution enables the system to perform well under extreme Voltage Standard Wave Ratio (VSWR) conditions up to a 6:1 ratio, while not requiring the use of an external isolator. This further reduces the cost and size of the system.

The highly integrated subsystem includes:

SKY74045 Direct Conversion Transceiver
The SKY74045 is based on Skyworks' full type-approved (FTA) single-chip direct conversion transceiver technology, which is included in more than 50 mobile platforms. The RF transceiver consists of a direct conversion receiver, a transmitter with integrated voltage controller oscillators (VCO) that utilizes Skyworks' Polar Loop modulation technology, and a fully integrated Fractional-N synthesizer.
Skyworks' advanced direct conversion architecture technology eliminates the need for special baseband processing requirements to provide customers with the flexibility to combine the subsystem with virtually any E-GPRS baseband solution currently available on the market.

The quad-band SKY74045 RF transceiver, when combined with the SKY74046 PA controller/modulator, seamlessly forms a closed loop transmit system around the SKY77316 PA.

The SKY74045 is fabricated using BiCMOS technology and is available in a 56-pin 8mm x 8mm land grid array (LGA) package.

SKY74046 PA Controller/Modulator
The PA controller is a highly integrated device used for power control and when combined with the SKY74045 transceiver enables transmit of both constant as well as non-constant envelope signals. The device requires a minimal number of external components to complete an automatic output control loop. The SKY74046 is fabricated using BiCMOS technology and is available in a 24-pin 4mm x 4mm land grid array (LGA) package.

SKY77316 PA Module
PA functionality is provided by a proven Skyworks module that incorporates a GSM850/900 PA block, a DCS1800/PCS1900 PA block, impedance-matching circuitry for 50 ohm input and output and a PA bias control block. The two separate HBT PA blocks are fabricated on a single gallium arsenide (GaAs) die to provide maximum performance in a small footprint. The SKY77316 is available in a 16-pin 8mm x 10mm multi-chip module (MCM).
Pricing and Availability
Skyworks' complete EDGE RF subsystem solution is sampling now with volume production scheduled to take place in the fourth calendar quarter of 2003. The module is priced at $8.50 in quantities of 10,000.