Research Of Ka-band High Power And High Efficiency GaN Power Amplifier Chip

With the development of communication technology,both civil and military communication systems have put forward higher requirements for the performance of microwave radio frequency devices.As the core of the system,power devices have always been a research hotspot.Nowadays,power semiconductor materials have developed to the third generation.Among them,gallium nitride(GaN)materials have the advantages of wide band gap,high potential barrier and high electron mobility.The output capability of power amplifier microwave monolithic(MMIC)based on GaN process is greatly improved.It is of great research value.At the same time,the occupation of the lower frequency band by the communication system has gradually become saturated,and it is urgent to develop a power amplifier MMIC with a higher operating frequency.In this thesis,a GaN high-power and high-efficiency power amplifier chip is designed based on the GaN high electron mobility transistor(HEMT)process.The main work is as follows:The thesis first analyzes and compares the important parameters of various power semiconductor materials,discusses the advantages of GaN materials used in power devices,and introduces the development history and current situation of GaN power devices.Then,the basic design theory of the power amplifier and the selected GaN process library are introduced as the basis for the power amplifier design in the following sections.Based on the 4×50?m transistor of GaN HEMT process,a single-stage power amplifier circuit working in the Ka-band is designed.The parallel structure of resistors and capacitors is used to improve the circuit stability.Good match.It is verified by simulation that the saturated output power of the single-stage power amplifier circuit is29.7d Bm,the power gain is greater than 9d B,and the maximum power density is4.45W/mm.Based on the single-stage power amplifier circuit,a high-power and high-efficiency power amplifier MMIC in this band is designed.The circuit adopts a three-stage recursive amplifying structure,the last stage is 16-cell output,the overall structure is strictly symmetrical,and the consistency between ports is high.Through the electromagnetic field co-simulation verification,the output power of the power amplifier circuit in the 27-31 GHz band reaches 20 W,and the power added efficiency reaches 30%.The circuit has been checked by the process rules,and the final layout area is 3.8×2.9mm,waiting for the tape-out for physical testing.Finally,according to the needs of the project,a passive double-balanced mixer working in the C-band is designed.After on-chip testing,the overall conversion loss of the mixer in the 4.5-6GHz band is less than 7.6d B,and the loss at the center frequency is7.1d B,the isolation between ports is greater than 25 d B.