Off-Chip Rf Components - LG KT610 Service Manual

3.6 OFF-CHIP RF COMPONENTS

3.6.1 ALM-1412(U603:GPS LNA)
The ALM-1412 is an LNA module, with integrated filter, designed for GPS band applications at
1.575GHz. The LNA uses AVAGO Technologies' proprietary GaAs Enhancement-mode pHEMT
process to achieve high gain with very low noise figure and high linearity Noise figure distribution is very
tightly controlled. A CMOScompatible shutdown pin is included either for turning the LNA on/off, or for
current adjustment. The integrated filter utilizes an Avago Technologies' leading edge FBAR filter for
exceptional rejection at Cell/PCS Band frequencies. The ALM-1412 is useable down to 1V operation. It
achieves low noise figure, high gain and linearity even at 1V, making it suitable for use in critical low-
power GPS applications or during low-battery situations.
3.6.2 SKY77519(U601:GSM FEM)
RF Front end consists of antenna, antenna switch module (SKY77519) which includes EDGE PAM.
The antenna switch module allows multiple operating bands and modes to share the same antenna. In
KT610, a common antenna connects to one of six paths: 1) UMTS-2100 Rx/Tx, 2) GSM-900 Rx, 3)
GSM-900 Tx, 4) GSM- 1800 Rx, and 5) GSM-1800, GSM-1900 Tx(High Band Tx's share the same
path), 6) GSM-1900 Rx. UMTS operation requires simultaneous reception and transmission, so the
UMTS Rx/Tx connection is routed to a duplexer that separates receive and transmit signals. GSM-900,
GSM-1800, and GSM-1900 operation is time division duplexed, so only the receiver or transmitter is
active at any time and a frequency duplexer is not required. The active connection is MSM-selected by
three control lines (GPIO[9], GPIO[10] and GPIO[11]). These GPIOs are programmed to be ANT_SEL0
, ANT_SEL1 and ANT_SEL2 respectively.
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Only for training and service purposes
3. TECHNICAL BRIEF
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