– 5-3 –
5.1.3. Functional Description
■
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
1,459.59 MHz -1,543.725 MHz
GSM 1800
1,710.2 MHz - 1,784.8 MHz
90.316 MHz - 1,04.776 MHz
1,354.737 MHz - 1,414.482 MHz
PCS 1900
1,850.2 MHz - 1,909.8 MHz
97.379 MHz - 1,12.341 MHz
1,460.684 MHz - 1,516.606 MHz
■
General
■
Antenna
EB-X300 uses a Helical-type monopole antenna which is optimised for operation on GSM, DCS and PCS bands.
RF circuit design is built based on the direction conversion transceiver IC integrated by SAW filters (U1201), power amplifier with
control circuit, and Transmitter/receiver switch.
RF LO always requires external frequency sources with VCTCXO.
The
LO is frequency is adjusted periodically to synchronise
with the network cell frequency.
F
VCO
= F
RX
3
2k
F
RX
F
VCO
UHF VCO
k = Frequency multiplier
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
