RF System Design Based On Integrated Transceiver AD9371

With the rapid development of mobile communications and the explosive growth of market's demands,the fifth generation of mobile communications is approaching,and the wider bandwidth and higher performance RF Transceiver system become relatively important.In the scenario of 5G mobile communication system,the high density and low latency are required,and the next generation of mobile communication RF transceiver system should have the advantages of high data rate,low transmission delay,multiple smart antennas and other technical requirements.The design is mainly based on Analog Devices RF transceiver AD9371 to build hardware platform.AD9371 has 2 inputs 2 outputs,and supports TDD and FDD duplex mode,the system bandwidth and RF frequency up to 100MHz,6GHz respectively.Direct frequency conversion method has been adopted,and the output digital signals are transmitted following JESD204B serial communication protocol,the maximum data rate up to 6.144Gbps.The design part includes the front-end module link budget,such as the low-noise amplifier to reduce noise figure and improve the sensitivity,the power amplifier to increase the output power and expand the coverage.The AD9528 clock distribution is used to distribute the 122.88MHz input reference signal to the digital processor Xilinx Zynq series and the RF processing unit AD9371.Finally,the AD9371 needs multiple supply ports.Therefore,ADP5054 high-efficiency power management chip can be used to achieve the isolation of different power pin.Finally,The System based on AD9371 chip not only has low power consumption,miniaturization and other characteristics,but also makes multiple pieces of system board operate simultaneously and achieve the link synchronization,and then set up massive MIMO to meet the future of 5G system design.The RF transceiver board's measured results agree with the simulated ones,the receiver noise figure is around 4.5dB in the 100MHz bandwidth,the receiver flatness is around 2dB,the receiving sensitivity is around-65dBm,the LO leakage is less than-60dBm,sideband suppression is better than-75dBc,On the other hand,the transmitter flatness is less than 0.5dB,The output intercept point OIP3 = 36.5dBm in the 100MHz bandwidth,the 1 dB compression P1dB = 27dBm,the adjacent channel power ratio on the upper side is ACPR = 47.4dBc @ 17dBm,the lower side band ACPR = 48.5dBc @ 17dBm measured by modulated signal 64QAM with 100MHz bandwidth,the carrier leakage is less than-35dBm,the sideband rejection is better than 50dBc by 17dBm single-tone measurement method,and spurious frequency out of the band is less than-45dBm.The EVMs at symbol rate 20Msps,40Msps,60Msps,80Msps and 100Msps is 1.12%rms,1.44%rms,1.74%rms,2.04%rms and 3.14%rms respectively.The TDD scheme is adopted in duplex mode and the switching time is less than 450ns.