(A) design of digital beamforming system using SDR and GNUradio

Abstract

Phased array technology has been developing with advances in integrated circuits, analysis and design programs. The conventional beamforming techniques have disadvantages that the more number of array antennas increase, the more complexity of beamforming system is large. For example, additional analogue block or analogue circuits should be needed to shift phase. Because of this reason, next-generation phased arrays will build on digitization, which can easily do digital signal processing and do not have to need additional analogue parts. However, there is not much research on this field yet. This dissertation proposes a digital array antenna beamforming system and technique. Because digital beamforming system is consist of lots of RF parts and analogue circuits, even if all reference signal synchronized is used, there is a phase difference between input signals due to chip tolerance, and temperature. To solve this problem, digital array calibration technique was designed using digital processing block with correlation coefficient. Also, digital phase shifter was designed with digital mixer and digital source. Using these digital processing blocks, three array digital beamforming system is fabricated and experiment results equal to simulation results are obtained.