Research On The Technology Of The Digital Beam-forming And Direction-finding

Array digital beam-forming and direction-finding technology is an importantdevelopment direction of the modern airspace signal processing, widely applied andgreatly developed in fields of modern radar, sonar, medical imaging, communication,confrontation and so on. Due to its high resolving power, array high-resolutiondirection finding algorithm, especially favored by academia. Digital beam-forming anddirection finding technology is an extension of the technology of simulated phasedarray. This new technology introduced digital signal processing method, based ontraditional analog beam-forming, as a combination technology of array antenna andsignal processing. In digital beam-forming and direction finding technology, arrayantenna receives airspace electromagnetic signals, performs acquisition of the signalsin the time domain and space domain, and weights phase and amplitude of thebaseband signal received by each antenna unit, then forms the digital beam with acertain shape to receive signal. Therefore, it implements spatial filtering of the signaland improves reception processing gain of the signal. Due to multiple digital beamreceiving the signal simultaneously and digital signal processing, it achieveshigh-solution and accurate direction finding of the target.On the basis of discussion the narrowband line array beam-forming, andcombined with engineering applications, this paper discussed the digital beam-formingtechnology of the wideband array and method of super-resolution in the targetdirection-finding. this paper are arranged as follows: Firstly, starting from the basicprinciples of digital beam-forming technology, this paper introduces the basiccharacteristics of the linear array antennas; Secondly, digital beam-forming methods ofnarrow-band signal, digital beam-forming methods of broadband signal, as well asarray lineup methods of broadband signals were discussed, and then the beam-formingalgorithms are mathematically simulated. Based on simulation results, performance ofdifferent algorithms was compared. Thirdly, various error factors in the array antennaand its effect onto digital beam-forming were analyzed, then an array mutual couplingcorrection method, suitable for engineering applications, was proposed; Fourth, digital multi-beam direction-finding algorithm suitable for the engineering application and theengineering implementation architecture based on digital beam-forming anddirection-finding technology were discussed, and the engineering implementationmethod of digital beam expansion and engineering factors of digital array systemengineering that should be considered in the aspect of signal processing werediscussed.