User's Manual

VS500 USER MANUAL
Confidential & Proprietary of VACOM 9/13 Page Date : 05-08-08, Rev No : 1.0
Control No.: MSD351A0VS500
Originated by Hard Ware 3 Team
3.3 RECEIVER PART
- RFR6122 ( LNA + RF to baseband Receiver_Quadrature I/Q Downconverter and internal VCO
for CDMA mode )
- Receiver band Pass Filter (balance 100ohm out put impedance)
- Antenna
- Duplexer
3.3.1 MAIN FUNCTION
- Divide Receive/Transmit signal
- Low noise Amplify
- Direct Conversion
- Quadrature Demodulation
- Filtering of TX band signal and noise
3.3.2 BASIC OPERATION
RX Frequency (881.5
±
12.5MHz) which is passed by duplexer amplified through LNA(Low Noise
Amplifier) path of RFR6122 and then input to pre-amplifier through RF SAW filter with balanced output.
The pre-amplifier drive RF signal to quadrature RF to baseband downconverter. The downconverted
baseband signals are multiplexed and routed to low pass filter. The filter output are buffered and passed
on to the MSM device.
3.3.2.1 ANTENNA: (AT500)
It optimizes transmit/receive of radio wave in the air. It is internal PIFA type.
3.3.2.2 DPX (DUPLEXER): (DX501)
It has the function of separating transmit/receive signals in the full duplex system using the
transmit/receive common antenna. Duplexer consists of the receive part band pass filter and the transmit
part band pass filter, and ideal duplexer provides perfect isolation between transmit and receive parts. In
other words, the transmit part band pass filter is used to suppress noises and spurious waves entering the
receive band among transmit signals in order to improve sensitivity.
RX TX
Center Frequency 881.5 MHz 836.5 MHz
Bandwidth
±
12.5 MHz
±
12.5 MHz
Insertion Loss 1.9 dB (Typ.) 1.7 dB (Typ.)
Attenuation 824~894 MHz (57dB) 869~894 MHz (45dB)