Design Of GaN-based X Band5Bits Digital Phase Shifter And CMOS Ultra-Wideband Low Noise Amplifier

With the rapid development of phased array radar technology, which demands higher performance of T/R module. Phase shifter is an important part of the phased array radar T/R module which was used to change the transmission signal phase. It directly affects the cost and performance of the phased array radar system.Broadband and high-speed communication will be the main trend of the future. As the first stage of the active circuit of Ultra-wideband T/R module in front of the receiver, its performance determines the acquired information is complete or not. Research on phase shifter and a low noise amplifier has important practical significance and market significance based on the above analysis. The main work of this thesis is as follows.Completed the design of five bits digital phase shifter based on GaN. Firstly, analysis the principle, characteristics, design methods and operating mode of various types of phase shifting circuit, providing a theoretical basis for topology selection and design optimization of phase shifting circuit. On the basis of the analysis of the principle of the phase shifter, simulated and optimalized five phase shift units and their cascade. Utilizing the measurement results of S-parameters of GaN HEMT as the switch device model, the phase shifter circuit are realized without mature transistor switch model, with the methods of optimizing the input matching for the transistor, a switch that suit to be used in the phase shifter circuit is designed, which alleviate the problem of much large insertion loss of the GaN HEMT. A five bits phase shifter of high and low pass network with the improved T-type bridge structure is designed. Simulation results show that the maximum absolute accuracy of the operating band phase error is5.763°, the basic function of the phase shift is correct.Completed the design of a CMOS ultra-wideband low-noise amplifier which applied in ultra-wideband radio receivers. Firstly, thesis analyzes the structure of the various wideband low noise amplifier and the technology to improve its performance. The results show that the matched input and output reflections S11and S22of the designed CMOS ultra wide-band low noise amplifier less than-10dB in the working frequency range of3.1-10.6GHz, noise factor of the center frequency is4.5dB, the maximum gain is15.3dB, in-band gain fluctuation is2.5dB.The power consumption is14.6mW.