Technical Manual

Page 6 of 13
CDMA:
Item Content Comment
Frequency band
CELL：869~ 894MHz
Channel bandwidth 1.23MHz
Receiver sensitivity < –104dBm (FER:0.5%)
Single Frequency
Interference Resist
< –101dBm (FER: 1.0%) Frequency
offset: 900KHz
Power: -30dBm
Frequency offset: ±0.9MHz/±1.7MHz, Power: ① -
43dBm
Frequency offset: ±0.9MHz/±1.7MHz, Power: ② -
32dBm
Inter-modulation
spurious response
attenuation
Frequency offset: ±0.9MHz/±1.7MHz, Power: ③ -
21dBm
<① –81dBm Conductibility
spurious emission
<② –61dBm
3.3. Other Electronic Specifications
SIM / UIM interface, Support either 3V or 1.8V
4. Phone Work Principles
4.1 RF circuit
4.1.1 RF circuit of CDMA
4.1.1.1Main functions of RF circuit:
The baseband CDMA signal is modulated by transmitting circuit, and
then is transmitted by antenna on the bandwidth: 824MHz~849MHz;
When the receiver circuit receives the signal on 869MHz~894MHz, it is
demodulated and becomes to the forward channel baseband CDMA
signal; and at the same time, provides the constant controllable
19.2MHz frequency source.
4.1.1.2 Structure of RF circuit:
We could divide it to 4 units according to the functions: Antenna unit,