Design And Implementation Of Control Circuit For Phased Array Antenna Based On FPGA

With the development of Direct Broadcast Satellite technology, the research of mobile satellite TV receiving system had been attracted more and more attention.Phased array with flexible beam-pointing, good direction and quickly non-inertial scan has become an important form of the mobile satellite TV receiving system.The phased array control circuit which can be used to mobile satellite TV receiving was designed, including Digital Down Converter module and phased control module.Phased control circuit changed phase of antenna array through controlling the shifter antenna, in order to change the beam-pointing. The simulation of control circuit was based on the FPGA-chip of the Corporation Altera.The main function of Digital down converter module make frequency downconversion from the high speed input signal to low speed baseband signal, which included programmable digital down converter module, CIC-Filter module, HB-Filter module and FIR-Filter module. In order to achieve high integration and reduce chip resources share, the CORDIC algorithm was used to implement programmable digital down converter module which reduced the use of multiplier and look-up table. The Distributed Algorithm was used for both HB-Filter module and FIR-Filter module, which can reduce the use of look-up table. Both HB-Filter module and FIR-Filter module were Higher-order finite impulse response digital filter, and the band can reach to 6MHz. Phased control module was designed with the idea of intelligent control, including signal comparison circuit, scanning direction judging circuit, Electronic scanning circuit and scanning output circuit. The FPGA hardcore resources were used less as far as possible during the whole system designed, and the multiplier which occupy more resources and had slower speed was not used, parallel input and pipelining technology were used to improve the running speed of circuit.