Design Of Phased Array Antenna With A Self-calibrating Network

After the use of an active phased array for a long time,the amplitude and phase values of the output of the receiving/transmitting modules will change due to the aging of some components in the link and the change of the surrounding environment.As a result,the amplitude and phase at the antenna feed ports are different from the theoretical value,which leads to the deterioration of the radiation performance.Therefore,the phased array needs to have the function of online monitoring and calibration in the process of use,which can independently discover and calibrate the errors between channels.In the thesis,a phased array antenna with a self-calibration network is studied for this requirement.In the thesis,a Ku-band phased array antenna with a self-calibration network embedded in the antenna element is developed.In view of the fact that the structure of improving scanning performance and the self-calibration network cannot be placed between the phased array elements at the same time,the structural fusion method was adopted.The Substrate Integrated Waveguide(SIW)back cavity was fused with a microstrip coupler,and a self-calibrating network with improved scanning performance was designed.The dynamic range of the coupling coefficient is reduced by designing reactance control blocks on the self-calibration network.After the Ku-band phased array antenna has the self-calibration network proposed in this thesis,the gain is increased by1.95 d B,and the sidelobe level is decreased by about 4.20 d B when scanning at –50° in the E-plane.At the center frequency of 16 GHz,the self-calibrated network coupling coefficient is between-18.9 d B and-22.2 d B.The Ku-band phased array antenna proposed in this thesis is experimentally studied by using multilayer printed circuit board(PCB)technology.And the scanning pattern and coupling coefficient are measured.In the thesis,a V-band phased array antenna with a self-calibration network embedded in the feedline is developed.By designing the transmission line of striplineSIW-rectangular waveguide(RWG)and fan-out the feedlines,the problem that the size of V-band chip is larger than the gap between elements and the chip and antenna unit cannot be connected vertically is solved.Based on the structure of the SIW-RWG transmission line,the SIW single window coupler for self-calibration is designed.The coupler is simple and compact,without additional metal laminated structure.At the center frequency of 60 GHz,the self-calibration network coupling coefficient is-40 d B±5 d B.Also,the V-band phased array antenna with the self-calibrating network is experimentally studied by using multilayer printed circuit board(PCB)technology,and its radiation performance is measured.The phased array antenna,frequency conversion module,waveform control board,power board,and other devices were assembled into a phased array system,and the scanning performance of the whole phased array is measured,and the beam can achieve ±50° scanning.