Design And Implementation Of Nonlinear Active Antenna Array Based On Coupled Oscillators Array

Under the conditions of informatization,seizing the right to information has become the key to mastering the initiative in war,as the "clair eyes" and "wind ears" in the battle,the radar is urgently required to be equipped in large quantities to satellites,fighter planes,balloons(airships),ships,and positions.However,traditional passive phased array antenna radar has many disadvantages such as large equipment,large power loss,expensive equipment,low reliability and maintainability,and so on.Emerging active phased array antennas have many advantages over traditional passive phased array antennas,but they are limited in the phase shifter to reduce the size of the antenna array,reduce control complexity,improve efficiency,improve phase shift accuracy,and reliability.In order to increase the digitization of active phased arrays,people began to study methods for implementing phased array antennas without using phase shifters.This paper proposes a nonlinear active antenna array(abbreviated as NLA3)technology based on a coupled oscillator array(abbreviated as COA),which can realize beam scanning and beamforming of the antenna array without a phase shifter,and has obvious effects on reducing the volume,cost,and loss of the antenna array.The main research contents and achievements completed in this paper are as follows:(1)Through the principle and implementation of the antenna array beamforming system,the disadvantages of implementing the beamforming system in several traditional phased array antennas are analyzed in detail,a method for designing a high-performance receive and transmit beamforming system using COA to achieve NLA3 is proposed.Starting from the analysis of NLA3 requirements,a COA-based NLA3 design plan was developed.(2)According to the basic theory of frequency-injection lockup,the nonlinear dynamic characteristics of injection-frequency phase-locked oscillators are studied,and several useful conclusions are drawn on the research of frequency-locked phase-locked oscillators.Based on this conclusion,a method of designing a microwave oscillator is proposed.Using this method,a 625 MHz COA unit based on an injection frequency-locked oscillator is fabricated.The COA unit was tested using the COA unit test system.The results show that the COA unit achieves stable injection frequency locking and meets the design requirements.(3)In-depth study of the signal bandwidth and phase noise of the COA basic topology,and analyze the shortcomings of the structure.An optimized topology structure was designed and a COA system was designed based on the optimized structure.The COA system was tested using the phase difference test system designed by the mixer.The results show that the phase difference between adjacent units of the COA can be adjusted independently(-180°,180°),which meets the design requirements.(4)The basic theory of NLA3 beamforming is analyzed.Based on this,how to use COA to realize NLA3 is studied,and the NLA3 system composed of 50 COAs is simulated and simulated.The result verifies the validity of this method.