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发表于 2009-5-18 20:24:42
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Description
The SKY77506 is a transmit and receive front-end module (FEM) with Integrated Power
Amplifier Control (iPAC™) for quad-band cellular handsets comprising GSM850/900, DCS1800,
and PCS1900 operation. Designed in a low profile, compact form factor, the SKY77506 offers a
complete Transmit VCO-to-Antenna and Antenna-to-Receive SAW filter solution. The FEM also
supports Class 12 General Packet Radio Service (GPRS) multi-slot operation.
The module consists of a GSM850/900 PA block and a DCS1800/PCS1900 PA block,
impedance-matching circuitry for 50 Ω input and output impedances, TX harmonics filtering,
high linearity and low insertion loss PHEMT RF switches, diplexer and a Power Amplifier Control
(PAC) block with internal current sense resistor. A custom BiCMOS integrated circuit provides
the internal PAC function and decoder circuitry to control the RF switches. The two
Heterojunction Bipolar Transistor (HBT) PA blocks are fabricated onto a single Gallium Arsenide
(GaAs) die. One PA block supports the GSM850/900 bands and the other PA block supports the
DCS1800 and PCS1900 bands. Both PA blocks share common power supply pads to distribute
current. The output of each PA block and the outputs to the four receive pads are connected to
the antenna pad through PHEMT RF switches and a diplexer. The GaAs die, PHEMT die, Silicon
(Si) die and passive components are mounted on a multi-layer laminate substrate. The
assembly is encapsulated with plastic overmold.
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