Multi-beamforming Technology Research And Chip Design Based On Path-sharing

There are still many unknown puzzles waiting to be solved in the universe,and the pace of human exploration has never stopped.In order to better explore the mysteries of the universe and meet the needs of faster sky survey speeds,wider detection angles,and higher sensitivity,the Square Kilometre Array(SKA)International Project was established.The important technology applied to signal processing in the SKA project is the beamforming technology.This technology is not only used in the SKA astronomy field,but also widely used in radar and communication fields.Its principle is to use phased array or timed array to coherently superimpose desired signals and destructively superimpose interference signals to achieve enhancement of signals in specific directions.Compared with the omni-directional transceiver system,the beamforming technology can significantly improve the receiving or transmitting gain and system efficiency.In order to meet the needs of various fields,especially the SKA field,a pathsharing broadband multi-beamforming chip based on a passive true delay unit is designed.A new path sharing true time delay beamforming architecture is proposed.Because of path sharing,the total delay is greatly reduced.This architecture can realize4 input and 4 output,and can be expanded to 2M input and 2K output.The passive LC filter is used to design the true delay unit structure,which can generate accurate and stable delay and realize the in-phase superposition of signals at the output port.The LNA is located in the first stage of the architecture,which can amplify the input signal based on the noise cancellation,so as to improve the noise performance of the whole system.The buffer amplifier compensates the gain attenuation and prevents the crosstalk between the signals,and makes the area differentiation design to make up for the gain difference caused by the path difference of different output ports.In this paper,the schematic design,layout design and post-simulation verification of the multi-beamforming chip are performed.Using HHNEC 0.18 ?m Bi COMS process,the layout area(including I / O pads and ESD)is 3.67 mm×3.62 mm.The simulation results show that the beamforming chip current in the operating band of 0.5–1.5 GHz is 186.37 m A at 1.8 V supply voltage.The input and output return loss is <-12 dB,the in-band overall gain is approximately 25 dB,and the gain flatness is <1 dB.The delay resolution is 80 ps and the maximum delay is 720 ps.When the antenna spacing is 10.5 cm,four scan angles of ±43° and ±13° can be provided.It has the advantages of small area,low power consumption,good gain flatness and good directionality.