Research And Design On T/R Multifunctional MMIC Based On GaN Material

With the development of information technology,antenna systems that use phased array technology have been widely applied in the fields of wireless communication systems and radar target detection.In the active phased array system,the transceiver(T/R)component used for receiving and transmitting signals is the key component of the RF front-end part,and its performance significantly impacts the overall performance of the system.Therefore,developing T/R components with high performance,small size and high reliability has become an important research area for systems.As semiconductor materials and fabrication processes are being updated from generation to generation,the use of wide-band gap semiconductor gallium nitride(GaN)materials with high breakdown voltage and output power characteristics allows GaN transceiver multifunctional chips,including power amplifiers,low-noise amplifiers and microwave switch monolithic microwave integrated circuits(MMICs),to become one of the preferred components in high-power T/R components.In K/Ka-band broadband satellite communication systems,with the development of dual-band transceiver phased array antenna units,the traditional transceiver multifunctional chips need to meet both high transmit power and broadband dual-band transceivers.To better improve the performance of dual-band transceiver phased array systems,dual-band transceiver multifunction chips have become a current research topic.This paper introduces the working mechanism of GaN high electron mobility transistor(HEMT)and the design basis of broadband transceiver multifunctional chip.The broadband MMIC amplifier matching technology,broadband high-efficiency GaN HEMT power amplifier,broadband low-noise amplifier and broadband switching circuit as well as the integrated design of the multifunctional chip have been investigated,and the research results are as follows.1.For the broadband amplifier design method,this paper proposes a broadband matching network design technique based on the approximate optimal impedance space,which avoids the problem of tedious calculations required in the design process of broadband amplifiers.The method adopts a combination of numerical and morphological methods,constructs multiple constraints for the impedance trajectory of the matching network,utilizes computer-aided design(CAD)to achieve accurate control of the impedance trajectory of the matching network,and proposes an automatic selection method for the reactance matching topology.The above method is used to design an 18-23 GHz 0.5 W broadband power amplifier and a 16-25 GHz broadband low noise medium power gain amplifier with a 3 d B noise factor,which provides a new idea to solve the matching network design problem of broadband power amplifiers and low noise amplifiers.2.Based on the input-output nonlinear characteristics generated by transistors,a broadband high-efficiency power amplifier design has been studied.Aiming at the output nonlinearity generated by the intrinsic capacitance of the transistor,the shortcomings of the conventional resistive reactance hybrid continuous mode in the wideband high-efficiency design method are studied,the output voltage waveform of the transistor is modified using an auxiliary factor,and a modified resistive reactance hybrid continuous mode is proposed,which provides a novel solution for the use of wideband high-efficiency mode in transistors with small optimal impedance.A 17-24 GHz 0.5 W wideband high-efficiency amplifier was designed for method validation,and the realized MMIC has 43% in-band power-added efficiency(PAE).Meanwhile,for the input nonlinearity generated by transistors,the efficiency and impedance variation of half sinusoidal input delivered to transistors have been studied,the gate waveform modulation technique for transistor efficiency improvement is proposed,and a GaN high power amplifier MMIC with 10 W continuous wave output power and 35% PAE at 17-21 GHz is designed to solve the efficiency improvement problem of reactance matching high power amplifiers.3.Based on transistor variable gain theory,a variable gain amplifier design method using a novel recurrent architecture is proposed.Combined with a broadband highly robust low noise amplifier design method,a 25-31 GHz variable gain low noise amplifier is implemented to meet the need for additional variable gain functions on the transceiver multifunctional chip receive link.The amplifier achieves an equally spaced variable gain range of 0 to 22 d B without affecting noise,providing high dynamic range for the receive branch.In addition,for the demand of transmitting and receiving dual-bands,the amplifier realizes 17-32 GHz wideband low-noise amplifier design covering 17-22 GHz and 22-31 GHz with a minimum noise factor of 1.8 d B by using frequency reconfigurable technology.4.Based on frequency reconfigurable technology,a single pole single throw switch circuit with bandpass filtering characteristics is designed to transmit and receive different frequencies in broadband satellite communication systems.It can operate at 16-22 GHz and21-33 GHz with a maximum insertion loss of 1.5 d B.The issue that the system transmits and receives different frequencies has been solved,and the corresponding operating signal paths are provided for the designed power amplifier and low noise amplifier.The symmetrical single-pole double-throw switch circuit designed using this topology avoids the problem of occupying a large area with a pure parallel switch topology and realizes the requirement of transmitting and receiving dual-bands.Meanwhile,an asymmetric single pole double throw switch circuit is also designed for transmitting and receiving dual-band,which improves the isolation between two channels and reduces the insertion loss of the transmitting link.5.Based on the study of the design method of each functional unit in the transceiver multifunctional chip,the corresponding GaN HEMT and switch transistors are developed using the GaN HEMT process,and the corresponding active and passive device modeling techniques are combined to design and fabricate the dual-band transceiver multifunctional chip for broadband satellite communication systems.Finally,the difference between the simulation and the measured results has been analyzed and summarized.