Design And Study Of Planar Array Antenna

With the rapid development of wireless communication technologies,communication systems have placed higher demands on the performance of antennas.The air-fed array antenna consists of a feed and a planar array,which combines the advantages of reflector antennas and microstrip array antennas.In terms of structure: the antenna has the characteristics of light weight,small size,simple feeding mode and easy manufacture.In terms of performance: the antenna has the characteristics of high gain,high efficiency and flexible beam control.Due to the simple phase control of the array element,both reflectarray antenna and transmitarray antenna show the advantages of designing the orbital angular momentum vortex-electromagnetic wave.The research of reconfigurable air-fed array antenna and the planar array generating orbital angular momentum have attracted more and more attention from scholars at home and abroad and become an important direction of antenna research.In this dissertation,we focus on the design of high-gain array antennas,the design of reconfigurable array antennas,and the application of array antennas in the generation of vortex electromagnetic waves.The details are as follows:1.The angle rotation method uses a fixed-size reflectarray unit to realize the design of a circularly polarized reflectarray antenna.The theoretical analysis of the angle rotation method is carried out,the feasibility of the angle rotation method to realize the circularly polarized reflection array antenna is deduced.The corresponding relationship between the rotation angle and the compensation phase is quantitatively analyzed.A novel type of reflectarray unit is designed.By optimizing the parameters,we obtain a wideband unit cell and design the circularly polarized reflectarray antenna using angle rotation method.Finally,the designed circularly polarized reflectarray antenna achieves 20% 1-dB gain bandwidth and 30% 3-dB axial ratio bandwidth.2.X/Ku dual-band single-layer reflectarray antenna is presented.The proposed reflectarray antenna operates in two separated bands with separate feeds.The reflectarray element is composed of a split ring with two phase delay lines and a phoenix patch.The split ring and phoenix patch are designed for operation at X-and Ku-bands,respectively.The split ring is selected as the lower frequency element because of the large enough internal space.The phase shift of these two elements does not depend on variation of external size,which provides a feasible method for designing dual-band elements.The lower-band phase shift is obtained by changing the rotation angle of the phase delay lines.The movement of the inner loop of phoenix patch provides the required phase shift for the higher band.The proposed element realizes 360°phase shift range in both bands.The reflectarray is fabricated and measured to validate the design.The measured gains are 22.9dBi at 8.5GHz with aperture efficiency of 40%,and 28.8 dBi at 16GHz with aperture efficiency of 44.8%.Besides,the 1 dB gain bandwidths are 20.5%(7.9GHz-9.7GHz)at lower band and 13.3%(14.7GHz-16.8GHz)at higher band.3.A double-layer highly efficient and wideband transmitarray antenna is presented.The transmitarray element is composed of four metal vias and two cross-patches with two stubs.The metal vias penetrate the entire substrate and arrange symmetrically.The cross-patches are printed on both sides of the dielectric substrate.The metal vias are introduced to enhance the coupling strength.The stubs are added to ensure sufficient phase shift range.The achievable transmission magnitude is greater than-2dB and the phase shift range exceeds 360° within the whole band.A transmitarray antenna using the proposed element was designed,manufactured and measured.The simulation and measurement results are in good agreement.The measured maximum gain is 29.2dBi at 18 GHz with 51.4% aperture efficiency.Experimental results show that the proposed antenna has a 1-dB gain bandwidth of 9%(17.2GHz-18.8GHz).The proposed double-layer transmittarray antenna realizes the low-profile characteristic,simplifies the design complexity and solves the problems of the mass and the cost.4.A double-layer wideband transmitarray antenna using two degrees of freedom elements is presented.The double-layer transmitarray antenna is composed of 441 elements.Each element includes four metal vias and two patches with two degrees of freedom(TDF)printed on both sides of the dielectric substrate.Four metal vias are used to achieve the maximum transmission magnitude and two patches with TDF are adopted to obtain a sufficiently large variation range of phase shift.A square transmittarray is designed,fabricated,and measured to validate the proposed design.Simulation and measurement results have good agreement.Experimental results show that the proposed antenna has high gain of 30.0 dBi at 21 GHz,aperture efficiency of 40% and 1-dB gain bandwidth of 9.6%(20.1GHz-22.2GHz).The proposed double-layer transmittarray antenna greatly simplifies the design complexity and reduces the thickness,the mass,and the cost with respect to existing transmitarray antennas.5.Digital 1bit reflectarray array antenna design.A multi-layer unit based on the concept of polarization rotation is proposed to realize the 1-bit phase shift.The magnetic current model and spatial matching are used to discuss the working principle,and the design and performance of the unit are simulated.In order to verify the performance of the unit,a transmitarray antenna is designed and fabricated.The designed transmitarray antenna realizes beam scanning in a wide-angle domain by controlling coding.Due to the wide operating bandwidth,simple beam control and strong scanning capability of the proposed reflectarray,the proposed reflectarray antenna has an important potential in satellite applications.6.Vortex electromagnetic wave generation based on transmitarray.This paper studies the distribution of energy and phase of vortex electromagnetic waves in space.The modal and characteristics of the vortex electromagnetic wave are analyzed and discussed.We calcualte the phase distribution of transmitarray element using the Matlab under different modes.A novel type of double-layer transmission element is designed,and the achievability of the performance of the transmitarray unit is analyzed by current distribution.Finally,an orbital angular momentum vortex electromagnetic wave generating device working in the ku band is designed.The proposed transmitarray antenna is manufacture and tested.The simulation and measurement performance have good consistency.