Study And Design Of RF Optical Transceiver Module For WCDMA Fiber-optic Repeater

3rd generation (3G) mobile communication technology has made great progress and now, it's begin to be taken into business use. Majority of telecommunications companies of the world have made the decision that use WDMA technology to setup their next generation networks, so WCDMA technology is the leading technology of 3G Technology. Fiber-optic repeater has many advantages such as easy to setup and convent to do maintenance work, and it can be formed to different network constructions according to the environment, so the fiber-optic repeater used for WCDMA network will be widely used in the future.The optical transceiver module is the most important part in the WCDMA optical repeater system. The paper discussed the theory of the circuit design and circuit design method. The module designed in the paper has the function that optoelectronic switching, FSK modern, RF compensation, AGC, LD bias current monitor, LD optical power monitor and alarm, PD received optical power monitor and alarm, RF power monitor, FSK operating mode monitor, FSK modulation signal power control and FSK received power monitor. The optical transceiver module for WCDMA fiber-optic repeater translates the signal at the frequency as high as 2100MHz, and the module also integrated with FSK Modern, monitor and control circuit, so the circuit design is much more complicated.The paper introduced the technology of fiber-optic repeater which use the optical transceiver, and discussed the theroy of circuirt design of the module. And then the paper made a circuit scheme of the module. The module design contains transmission line, bias and APC circuit of LD, low noise and high linearity RF circuit, FSK modern, monitor and control circuit design and PCB layout. After the PCB design, the board tested by the equipments and got the conclusion that the design met the requirements.