Research On Millimeter-wave Wide Angle Scanning Phased Array Antenna Based On Ridged Substrate Integrated Waveguide

With the rapid development of modern wireless technology,phased array antennas can adjust the direction of high-gain beams or form special beam shapes according to requirements,which is very important for the fields of millimeter wave communication（5G/6G）,radar,imaging and detection,etc.In particular,phased array antennas with wide-band and wide-angle scanning have become a research hotspot.The substrate-integrated ridge waveguide is a new type of waveguide structure proposed in recent years that combines the advantages of the substrate-integrated waveguide and the ridge waveguide.Features such as low loss.In this paper,for the 5G millimeter-wave frequency band（24.25-29.5GHz）,three phased array antennas are designed based on the substrate-integrated ridge-waveguide slot antenna array sub-array,and the radiation characteristics of different forms of the substrate-integrated ridge waveguide slot antenna are analyzed.The influence of different feeding networks on the overall performance of the antenna,the designed antenna has the advantages of wide bandwidth,wide scanning angle,simple structure and easy integration.The specific research contents of this paper are as follows:1.High isolation collinear slot phased array antenna based on PCB technology:the substrate-integrated ridge waveguide structure composed of metal strips and metallized vias equivalent to lower ridges has the characteristics of broadband and small cross-sectional size.The slot realizes the slot antenna array based on the ridge waveguide.The centerline collinear slot is adopted,and the ridge is bent into a curved form to disturb the current to realize radiation,so that the low cross-polarization ridge waveguide slot antenna array sub-array can be realized.On this basis,the 1×4-element column sub-arrays are distributed at equal intervals on the E surface（scanning surface）to form a 4-element array with an array spacing of 0.53?_?.A choke slot equivalent to a dielectric through hole is added between the array elements to improve the port isolation..The simulation shows that the impedance bandwidth of the 4×4 element antenna array is 11%,the peak gain of the array reaches 13.7d Bi,the isolation of the array port is below-16d B,and the scanning of more than±50°can be achieved in the entire frequency band.The test and simulation are basically consistent.2.Broadband high-gain phased array antenna based on LTCC process:the series-parallel combined feed network has broadband and low-loss transmission characteristics,and the upper-layer ridge waveguide slot antenna is fed by the substrate integrated waveguide slot coupling,which broadens the impedance of the antenna bandwidth.Adding a slot on the non-scanning surface effectively increases the radiation aperture and improves the gain of the array sub-array,thereby realizing a broadband and high-gain ridge waveguide slot antenna array sub-array.On this basis,the 1×8-element column sub-arrays are distributed at equal intervals on the E surface（scanning surface）to form a 4-element array with an array spacing of 0.46?_?,adding isolation grooves between the array elements and periodically arranged metallized vias are equivalent The metal walls improve coupling and improve scanning performance.The simulation shows that the impedance bandwidth of the 4×8 element antenna array is 20%,the in-band gain is higher than 15d Bi,the isolation of the array port is below-15d B,and the scanning of more than±55°can be achieved in the whole frequency band.The test and simulation are basically consistent.3.Low-cross-polarization collinear slot wide-angle scanning phased array antenna based on LTCC process:adopt centerline collinear slot,and maintain the symmetry of the overall structure of the antenna to reduce the cross-polarization of the array;add metal walls on both sides of the slot Reducing the aperture efficiency effectively widens the unit beam width,thereby realizing a low cross-polarization wide active beam width ridge waveguide slot array sub-array.On this basis,the 1×4-element column sub-arrays are distributed at equal intervals on the E surface（scanning surface）to form a 4-element array,and the array spacing is 0.4?_?.The simulation shows that the impedance bandwidth of the 4×4 element antenna array is 20%,the peak gain of the array reaches 13.7d Bi,and the scanning of more than±60°can be achieved in the entire frequency band.The test and simulation are basically consistent.