Study On The Four-dimensional End-fire Antenna Arrays With Integrated Feeding Networks

End-fire phased antenna arrays and circularly polarized phased antenna arrays are widely used in military and civil applications. However, modern wireless systems often pose very strict and even harsh requirements on the end-fire phased antenna arrays or circularly polarized phased antenna arrays, such as wide beam scanning angles, wideband, ultra-low sidelobes or low cross polarization components, which are often too difficult to meet simultaneously. By introducing an additional time dimension, four-dimensional(4D) antenna array can be sued to effectively reduce the difficulty of the design of traditional end-fire phased antenna arrays which depend on feeding amplitude and/or phase only.This thesis focuses on the technology of 4D antenna array and phased antenna array. The 4D antenna array technology is applied to the design of circularly polarized antenna arrays and end-fire phased arrays. The main contents are divided into three parts.Firstly, a planar end-fire phased array is designed at lower frequency band. The principle of directional superposition and symmetric boundaries are used in the simulation, in order to realize an end-fire scanning within the ± 25 degrees of scanning range. Detailed analysis has been made. In addition, the phenomena of beam up-squinting is analyzed and discussed, and some improvement approaches are briefly discussed.Secondly, 4D antenna arrays and sequence rotation technologies are used to design a 16-element circularly polarized linear antenna array. The cross polarization component is reduced in the main lobe direction, and high circular polarization purity is obtained. Moreover, the time modulation technique in 4D antenna arrays is made full use of on the design of the circularly polarized antenna array. By using DE algorithm, the time scheme and static excitation amplitude for each element are optimized respectively. Ultra-low sidelobe pattern is obtained, and the cross polarization component is also suppressed in the main lobe direction at the same time.Finally, this thesis focuses on the study of the 4D end-fire antenna arrays integrated with feeding network. A lot of analysis and experiment have been done to study the integration and miniaturization for 4D antenna array integrated with feeding network. It is more efficient in practical application without the additional RF switch system. Quasi-Yagi, umbrella dipole microstrip antenna array are designed. Ideal radiation pattern and bandwidth is obtained. According to a novel time modulation scheme, phase-shifting switch circuit is proposed and designed. Two channels are used to realize 180 degree phase shift, so as to improve the antenna efficiency of the 4D antenna arrays. Experimental results of the phase-shifting switch circuit show that the circuit meets the requirements of the novel time modulation scheme.