– 5-3 –
5.1.3. Functional Description
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Frequency Plan
The frequency plan is shown below:
Figure 5.2. Receiver Block Frequency Plan
TX Frequency
TX Frequency Plan
TX IF
TX RF LO
E-GSM 900
880.2 MHz - 914.8 MHz
88.46 MHz - 114.35 MHz
1459.59 MHz -1543.725 MHz
GSM 1800
1710.2 MHz - 1784.8 MHz
90.316 MHz - 104.776 MHz 1354.737 MHz - 1414.482 MHz
PCS 1900
1850.2 MHz - 1909.8 MHz
97.379 MHz - 112.341 MHz 1460.684 MHz - 1516.606 MHz
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General
■
Antenna
EB-A100 uses Helical-type antenna, which is most low-cost, monopole-like antenna. The antenna takes different spacing to
define bands of GSM, DCS and PCS.
RF circuit design is built based on SKYWORKS-74963 direction conversion transceiver IC integrated by SAW filters, power
amplifier with control circuit, and Transmitter/receiver switch.
RF LO always requires external frequency sources with VCTCXO. And LO frequency is periodically re-tuning to synchronize
with cell or network.
F
VCO
= F
RX
3
2k
F
RX
F
VCO
UHF VCO
k = Frequency muliplier
Where k is 1 for low band and 2 for high band.
x 1
x 2
x 2
/3
90
°
90
°
RX RF from
LNA
Fractional-N
PLL
RX Q
RX I
