Design And Research Of 5G Millimeter Wave Broadband GaN MMIC RF Front End

With the rapid development of modern wireless communication,the technologies of the fifth-generation(5G)millimeter-wave with abundant spectrum resources are the development trends for future communication systems.As the representative of the third generation of semiconductors,GaN devices have excellent frequency characteristics,high breakdown voltage and high electron saturation rate.Simultaneously,monolithic microwave integrated circuits(MMIC)are the best choice for the designs featuring miniaturization and high integration.Thus,the circuits designed based on GaN MMIC can meet the high-performance requirements of the 5G millimeter-wave radio frequency(RF)front-end chips.Based on the current domestic and international situation as well as the competitive environment of the 5G communications,the research on GaN MMIC RF front-end chips for 5G millimeter-wave communication has important research significance and engineering application value.The main research contents of this paper are as follows:(1)In order to meet the requirements of the 5G millimeter wave,an ultra-wideband low noise amplifier(LNA)featuring high gain and low noise is designed based on the OMMIC GaN/Si process.By using negative feedback technology and a wideband matching network,the LNA can achieve high flat gain and low noise within the operating frequencies of 20-45 GHz.(2)In order to realize the high-efficiency,broadband,deep back-off and miniaturized power amplifier(PA)for the 5G millimeter-wave bands,four millimeter-wave PAs are designed.Firstly,two broadband PAs with operating bands from 24 to 30 GHz are designed based on the processes of OMMIC GaN/Si and WIN GaN/Si C,which show higher efficiencies,higher integration and smaller circuit size compared to some state-of-the-art broadband PAs.Secondly,a broadband Doherty power amplifier(DPA)with high saturated and back-off efficiencies is designed based on the OMMIC GaN/Si process.Finally,based on the OMMIC GaN/Si process,an ultra-wideband PA is designed by using the common inductive negative feedback structure and wideband matching network,which can realize high efficiency and gain within the operating frequencies of 24-40 GHz.(3)In order to mitigate the contradiction between the insert loss and isolation of the SPDT switches,inductance resonance is applied based on the conventional series-parallel structure of transistors to improve the performance of the switch.Tow modified SPDT switches are designed using two different GaN processes,which both show good insert loss and isolation within the operating frequencies of 24-30 GHz.(4)Based on the aforementioned GaN PAs,LNA and the modified SPDT switches,the method of collaborative design is applied to design a 24-30 GHz RF front-end chip using the OMMIC GaN/Si process.The transmitted efficiency of the circuit is larger than 28 %,and the noise figure is below 2.2 d B in the received mode.Moreover,the circuit shows the advantages of compact circuit size and low cost.In this paper,the millimeter-wave GaN RF front-end chips are studied and designed.The proposed designs have the potential application in wireless communication.