Research And Design Of Four Channel RF Optical Transceiver Module Based On FPC

Nowadays,the trend of global informatization is more and more obvious,and the mobile communication network has become an indispensable part of people's life.In the context of increasingly high data transmission rate requirements,the traditional cellular network structure is faced with such problems as working bandwidth,energy consumption and delay,which has been difficult to meet the requirements of the Fifth-generation mobile network(5G).Radio Over Fiber(ROF),which combines wireless communication technology and optical fiber communication technology,has become a promising solution.The transmission performance of the ROF link is directly determined by the optical transceiver module used for electro-optical and electro-optical conversion.Therefore,it is urgent to study the RF optical transceiver module with multi-channel,high linearity,and large dynamic range.In this paper,a high linearity four channels optical transceiver module based on flexible printed circuit(FPC)is studied and fabricated.The main research contents and innovative results are as follows:(1)The main characteristic indexes of the RF optical transceiver module are described,including bandwidth,cross-talk and spurious-free dynamic range(SFDR).The mathematical model of the signal line in FPC is also constructed,and the parameters affecting the performance of the RF signal line in the flexible circuit board are analyzed.(2)The structure design and RF performance simulation of FPC in integrated four channels direct-modulated analog optical transceiver module are studied.High-performance FPC for RF optical transceiver module is designed by using Cadence software and HFSS 3D Layout software.When the input RF frequency in the range of 0?15GHz,the return loss of FPC used in transmitter optical sub-assembly(TOSA)is more than 25d B,the insert loss of each line is less than 0.19d B,and the cross-talk between two adjacent channels is less than-64d B.The return loss of FPC used in receiver optical sub-assembly(ROSA)is more than21d B,the insert loss of each line is less than 0.26d B,and the cross-talk between two adjacent channels is less than-50d B.(3)A high performance and low cost four channels RF optical transceiver module has been successfully developed.Experimental results show that SFDR of each channel is above91d B·Hz^2/3 when the input RF frequency in the range of 0?13GHz,the insertion loss of each channel is below 7d B when the input RF frequency in the range of 0?15GHz,and the cross-talk of two adjacent channels is below-15d B when the input RF frequency in the range of 0?20GHz.After the optical back-to-back transmission,the measured EVM of64QAM-OFDM signals with 20MHz bandwidth and 5GHz carrier frequency is less than1.8%.(4)The parameter control software of the TIA chip in integrated four channels direct-modulated analog optical transceiver module is designed.The control circuit design and the control program of MCU are completed.TIA gain,bandwidth and other parameters can be controlled and TIA input optical power information can be monitored in real-time.