Research On Beam Controlling Techniques Of Phased Array Radar

Beam steering system is an important part of active phased array radar. The main function of beam steering system is to form a specific point, with low side-lobe beam and capable of avoiding specific interference signal of beam. Based on the practical requirements of a phased array radar project, the paper first studies and simulates zeroing method algorithm which instructs how to form a signal evading a particular interference beam. Then this project designed and made a T/R module that can control amplitude and phase parameters of the beam control circuit system. Finally zeroing method algorithms are implemented with MODELSIM according to peripheral features of the Circuitry. This paper proposes a new way to implement beam steering system in hardware, which has the features of strong computing capability and data throughput.The engineering design method of zeroing method algorithm can be implemented easily and applied universally.In the part of zeroing method algorithm simulation, this paper first studies the math model of uniform linear array. Then Zero Constraints is proposed, which makes use of Least Squares and Lagrangian to solve the optimal coefficients. Finally, we get the formula to calculate the coefficients of zeroing method algorithms. In this simulation, the impact of the zero-order constraints on the waveform is analyzed, laying the foundation for the follow-up engineering implementation.In the process of FPGA implementing zeroing method algorithms, this paper first analyzes and compares several methods of signal processing. Then with the results of the project algorithm simulation a zeroing method and application based on FPGA implementation block diagram is devised. In order to achieve seamless connection with the floating-point DSP, all data in the diagram are in the form of standard single-precision floating-point, compatible with standard IEEE754. Main operations in the project are multiply-add in vectors and matrices. When implementing the diagram, IP cores are adopted as the core algorithm, and state machines are adopted to complete timing control. The whole process is completed with MODESIM and QUARTUS II.The first step of the circuit implementing process is analyzing and studying structures of beam steering machines. Secondly beam steering system based on DSP and FPGA is designed according to project requirements. In the end of the project, the system is applied to practical project after welding and debugging. ADI's TS101 and ALTERA‘s EP2S90 make up the Core computing unit of the beam steering machine, and it has a powerful data processing capability. The system has rich peripheral interfaces. It can control an 8× 8-array-element T/R module and realize the network and serial port control through PC with than 16 IO command expansion interfaces. What's more, the system features with a strong data storage capacity, including a FLASH with 2G× 8-bit look-up table and a 512K× 32-bit ping-pong seamless real-time RAM.