Skyworks Solutions, Inc. introduced a suite of front-end modules (FEM) with
breakthrough power control performance for quad band cellular handsets.
The unique power control scheme is based on a coupler detector which
greatly enhances the total radiated power (TRP) performance. These small
footprint and highly efficient GSM, GPRS and EDGE solutions support
Broadcom's, Infineon's and MediaTek's 2.5G and 3G platforms.
"Skyworks' highly integrated front-end modules utilize a small footprint
and unique power control scheme to improve total radiated power
performance - a key factor in today's advanced handsets," said Thomas
Richter, Skyworks' director of product marketing for front-end
solutions. "Our complete transmission to antenna solution with
integrated electrostatic discharge network is the perfect combination
for today's mobile handset manufacturers as they look to reduce
bill-of-materials and printed circuit board footprint."
Skyworks' 2.5G and 3G FEMs with Unique Power Control Scheme
The SKY77527
(8 x 6 x 1.12 mm) - optimized for Infineon's reference designs - and the
SKY77528 (8 x 6 x 1.1 mm) - supporting Broadcom's platform - consist of
a GSM850/900 and DCS1800/PCS1900 PA block, impedance matching circuitry
for 50 ohm input and output impedances, a multifunction PA control (MFC)
block, low pass harmonic rejection filters, and a single pole six throw
(SP6T) antenna transmit/receive (T/R) switch. The MFC in the SKY77527
provides "pinout" for interoperation with an external power control
loop. The external circuit uses the linear detector output to provide
closed loop power control in EDGE and gaussian minimum shift keying
(GMSK) modes of operation.
With an integrated saturation, detection and correction circuit, the SKY77528
also improves phone reliability with output radio frequency spectrum
(ORFS) performance in voltage standing wave radio (VSWR) and low-battery
condition.
The SKY77529
(7.5 x 7 x 1.1 mm) - optimized for Infineon's reference designs -
consists of a GSM850/900 PA block and a DCS1800/PCS1900 PA block, a
printed directional coupler for each block impedance-matching circuitry
for 50 ohm input and output impedances, a MFC block, low pass harmonic
rejection filters, and a SP8T antenna T/R switch. The FEM, with an
antenna that connects to any one of two reception (Rx) or four wideband
code division multiple access (WCDMA) Rx/Tx ports, incorporates full
support for a serial peripheral interface (SPI) bus function.
The SPI controller, which offers convenient digital control, accepts SPI
telegrams with data fields that support PA and switchplexer-related
functions. All FEM operating modes and switch states shall be determined
by the SPI telegram. The MFC provides pinout for interoperation with a
specified transceiver that will establish a closed loop power control
mechanism. The external circuit uses the linear detector output to set a
fixed bias point for 8PSK (EDGE) mode and a variable bias point for GMSK
(GSM) mode, which allows easy-to-implement timing and calibration.
Finally, the SKY77546
(7 x 6 x 1.0 mm) consists of an extended global system for mobile
communications (EGSM900) PA block and a DCS1800 PA block,
impedance-matching circuitry for 50 ohm inputs and outputs, a
multi-function PA control block, low pass harmonic rejection filter, and
a Tx/Rx antenna switch. Supporting MediaTek's low-cost EDGE platform,
the module contains a diplexer filter which provides excellent harmonics
and electrostatic discharge (ESD) performance.