Research On Key Technologies In Si-based Phased Array Transceiver

Phased array technology,which has been widely used in radar applications,can achieve directional beamforming,thereby both the radiation power of transmitter and the sensitivity of receiver are improved,and the interference signals in different directions are effectively restrained.With the continuous development of wireless communication technology,beamforming has become an indispensable technology in wireless LAN and mobile communication applications.At the same time,the development of microwave integrated circuit technology reduces the cost of phased array system.Therefore,phased array technology is gradually being applied in wireless communications.At present,there are relatively few researches on the integrated phased array transceiver modules in wireless communication applications.Phased array technology is widely required and has good application prospects in many fields.In this Dissertation,the key technologies of the main modules in the phased array transceiver are studied by using silicon based process.And a phased array transceiver is designed for WLAN,ETC applications in 5 GHz band.Firstly,the key technologies of low noise amplifier,power amplifier and phase shifter in phased array transceiver system are studied.The design experience and technical achievements of each module are accumulated through circuit design and measurement: 1)A high gain low noise amplifier operating in the X band is designed and fabricated by using 0.18 ?m SiGe process,and the key points of RF layout design are discussed based on measurement.2)Based on the analysis and comparison of the principles and characteristics of different broadband high efficiency power amplifiers,the integration of Class-J power amplifier is studied in detail.In order to reduce the performance loss during integration,a fullly integrated Class-J power amplifier with stacked-FET structure is proposed.The design and implementation is based on 0.18 ?m CMOS process.The test results showed that the designed power amplifier can achieve a power-added efficiency(PAE)of 43%.3)Based on the 0.13 ?m SiGe process,a 6 bit passive phase shifter operating in the X band is designed and fabricated using the conventional all pass and high-low architecture.According to the measurement results,the disadvantages of traditional phase shifter structure are analyzed.Based on the researches of main modules,a phased array transceiver for wireless communication applications in the 5 GHz WLAN band is designed by using 0.18 ?m SiGe process: 1)Based on the research of X band LNA,a low noise amplifier operating in the 5-6 GHz band is designed.The performance of the circuit is verified by postsimulation 2)Based on the research of Class-J power amplifier,a fully integrated ClassJ power amplifier operating in the 5-6 GHz band is designed with the same topology.According to the post-simulation result,the power amplifier achieves a PAE greater than 44% in this frequency band.3)Based on the research of X band phase shifter,aiming at the problem of low phase accuracy and poor impedance matching of traditional 180o phase shifter structure,a differential 180o phase shift structure and a differential all pass phase shift structure is proposed.The 5 bit phase shifter operating in the 5-6 GHz band is designed by using the proposed differential structure and the traditional structure respectively,the performance of two structures are compared in post-simulation,and the performance improvement of the differential structure is analyzed.4)Based on the designed 5-6 GHz low noise amplifier,power amplifier and phase shifter,a phased array transceiver is designed for the 5 GHz WLAN band,and its performance is verified by post-simulation.