Research And Design Of Microwave Solid-State Power Amplifier Based On Waveguide

Solid-state power amplifiers are an important part of solid-state transmitters and are widely used in various fields such as radar detection,satellite communications,remote sensing,electronic countermeasures,and so on.However,with the development of wireless communication technology,spectrum resources have become tighter and application scenarios have become more complicated.Higher requirements have been placed on the volume,bandwidth,and output power of solid-state power amplifiers.Waveguide transmission has the advantages of low loss,broadband,and large capacity,and is widely used in the field of microwave communications.This thesis researches on the basis of waveguide space synthesis technology,investigates the related achievements and development trends in recent decades at home and abroad.Analyzes the advantages and disadvantages of several waveguide synthesis methods,and designs several feasible Waveguides-Microstrip transition scheme.Based on the ridge waveguide theory,an ultra-wideband high-isolation power divider with 6-18 GHz is designed.The power divider uses a standard ridge waveguide WRD650 as the transmission channel.By adding a microstrip probe and matching load in the middle of the T-section,a quasi-plane magic T structure is realized,which effectively improves the problem of insufficient isolation of the traditional T-junction.Processing test results show that in the 6-18 GHz range,the input return loss is greater than 15 dB,the insertion loss is less than 3.4dB,and the isolation is more than 10 dB from 7.6 to 13.8GHz.In order to achieve miniaturization and broadband specifications,the operating frequency is extended to 18-40 GHz based on 6-18 GHz,and the number of synthetic channels is also expanded from 2 to 8.Try to use a compact design to reduce unnecessary transmission and transition losses.Transition mode adopts E-face double microstrip probe structure.The microstrip probe uses an improved wilkinson one-two structure,multisection matching to achieve broadband transition,through a four-way transition from top to bottom and left and right,to achieve a one-eight-way design.The final test results verified the feasibility of the program.The 18-40 GHz frequency band is relatively wide,so there are fewer corresponding amplifier chips.In order to meet the output of higher power,it is extended to a one-minuteand thirty-two synthetic network on the basis of one minute and eight channels.Fourridge waveguide power divider,followed by four-way one-minute eight structure.In order to improve the reliability,the entire synthesis network uses multi-layer machining.Back-to-back test results show that the synthesis efficiency is more than 60%.A Ka-band 10 W solid-state power amplifier was developed.The power amplifier system adopts a modular design with high reliability.The power amplifier module adopts multi-stage cascade amplification and the link gain is greater than 60 dB.The last-stage amplifier chip adopts the NC-11311C-2431P4 power amplifier chip whose saturation output power is greater than 36 dBm.The maximum synthesis efficiency of the power amplifier module is greater than 80%,and the output power is greater than 10 W,which meets the index requirements and provides a reference for practical engineering applications.