Design On Multi-beam Arrays RF Front-end Chip

Beamforming is a spatial filtering technology which is capable of transmitting or receiving signal directionally.It is widely used in many science and technology fields,such as radar,radio astronomy,wireless communications,sonar,biomedicine,seismology and acoustics.The basic principle of beamforming is that it can process the signal to be transmitted or received of a phased array in such a way that signals at particular angles experience constructive interference while others experience destructive inter-ference.Compared with omnidirectional transmission or reception,beamforming signif-icantly enhances gain.Beamforming technology is classified according to the number of output ports as single-beam forming and multi-beam forming.The former maximizes signal gain from or to a certain direction through spatial filtering,and the latter max-imizes signal gain from or to several different directions.Compared with single-beam forming,multi-beam forming processes data more efficiently and will be more wide-ly used in the future,so it has drawn more and more attention of scholars all over the world.A highly reused multi-beam forming RF front-end chip is designed in this the-sis.The chip features 4 input port and 4 output ports,in which signals of different paths share network nodes and circuit blocks such as low noise amplifiers,buffers and wideband true time delay units.Multi-beam forming is realized using relatively simpler circuit,so chip area and power consumption can be smaller.The operation frequency of the multi-beam forming RF front-end designed in this thesis is from 0.35GHz to1.5GHz,and the relative bandwidth is 124%,so all the blocks in the beamforming cir-cuit need to be designed for wideband usage.The low noise amplifier employs noise cancelling technique.Input impedance matching and wideband circuit design is realized by using a resistive feedback,and noise is cancelled using a source follower and a in-verting common source amplifier.Transmission lines and bessel filters are employed to realize the true time delay required.The multi-beam forming RF front-end chip is implemented using 0.18?m RF C-MOS process in the case that spaces between adjacent antennas is 104mm and the max-imum scanning angle is 45~?.