Research On Tiled Phased Array Antenna With Nonpower Of 2 For Low-earth-orbit Satellite Communication

In recent years,satellite communications have developed towards a high-throughput and low-orbit trend to meet the demand for large capacity and high data transmission rate in the development of wireless communications.The tile-type active phased array antenna is small in size,low in profile,fast in beam switching,and high in integration.It has strong application value for satellite communications with extremely high space utilization.Irregular tile-type active phased array antennas can be applied to specific space size designs in space-stricken satellite communications,and they are no longer limited to the conventional power-of-two array scale.They can also be effectively integrated with various radio frequency devices.At the same time,the vertical layout of each module of the phased array system can also improve the space utilization of the system and meet the needs of different projects,which has strong practical application significance.Thesis focuses on the research of non-two-power square tile-type active phased array antenna.The main content of this thesis is as follows:(1)A Ka-band non-power-of-two active phased array antenna is researched and designed.First,the optimal array size of the antenna in a limited area to be 10×10 and thesis selects Ka-band active chips to determine the tiled phased array antenna stack structure,array layout,and feed network routing plan,and then determine the antenna unit form;Secondly,on the basis of the antenna sub-array design,the sequential rotating feed structure is used to improve the cross-polarization and axial ratio characteristics of the antenna array,and the decoupling analysis of the antenna array is carried out by introducing a grounded metal grid structure.The design of 1 point the 24 constantamplitude in-phase power divider is used to control chips;Finally,the 10×10 active phased array antenna is processed and tested based on the multilayer PCB process.The measurement results show that the working frequency band is 30.5 GHz?31 GHz.The effective gain inside is 22 dBi,the scanning range of the elevation plane and the azimuth plane is ±40°,and the antenna axis ratio within the scanning range is less than 3 dB.(2)A K-band non-power-of-two active phased array antenna is researched and designed.First,the optimal array size of the antenna to be 6×7 under the same design area as the Ka-band,and thesis selects the K-band active chip to determine the tiled phased array antenna stack structure,array layout,and feed network routing plan,and then determine the antenna unit form.Aiming at the self-excitation problem that may occur in the K-band phased array,the isolation of the antenna array is improved by adding a back cavity to suppress the coupling between the antenna elements;Secondly,the control of the chip is completed by designing a 1 minute 12 constant amplitude in-phase power divider;And finally based on the multilayer PCB process,the 6×7 active phased array antenna is processed and tested.The measurement results show that the effective gain in the band is 18.7 dBi in the working frequency band 20 GHz?20.5 GHz,and the elevation and azimuth planes can reach with ±30° beam coverage,the antenna axis ratio is less than3 dB within the scanning range.