| During recent years,millimeter wave broadband antenna as an important part of satellite communications,radar reconnaissance and other fields,its ability to carry information and transmission rate plays a key role in the wireless communication system.The circularly polarized(CP)antenna has the advantages of resisting multipath interference and avoiding polarization mismatch,which has high research value and usage significance.In this paper,the research objective is to increase the radiation intensity and improve the radiation direction in the design of microstrip antenna arrays and magnetoelectric dipole(ME-dipole)antenna arrays,and the main contents are as follows:1.Two miniaturized CP antenna arrays are designed with the research goal of improving radiation intensity.The antenna unit is designed with a wideband ME-dipole and probe feed design to achieve circular polarization through tangential electric dipole and perturbation.Additionally,the magnetic dipole is achieved through metalized vias design for a low profile.The units are arranged in a 2x2 parallel array to enhance radiation intensity.Based on the experimental results,it was found that the impedance bandwidth is 41.5%(29.2-44.5GHz)and the AR bandwidth is26.7%(34.7-45.4GHz).The gain was observed to be stable at 13.7d Bic,with radiation efficiency being above 80%.Additionally,the compact size of the system offers the benefits of broadband,high gain,and miniaturization.Another one presents a differential fed CP planar aperture antenna array that utilizes substrate integrated waveguide(SIW)as the feed network to reduce the antenna profile.The measured results indicate an impedance bandwidth of 33.3%(28.1-39.3GHz),an AR bandwidth of 12.4%(35.0-39.6GHz),a peak gain of 15.8d Bic,and a cross-polarization level above 20 d B.This technology offers the benefits of both broadband and high gain,similar to traditional aperture antennas,but with the added advantage of a smaller size and the ability to be easily integrated with differential circuits.2.To design two wide AR CP antenna arrays with different arrangements with the objective of improving the radiation direction.The proposed antenna design consists of a microstrip line-metal via feed CP microstrip antenna with an added arc patch on the radiation patch.This expansion of the AR bandwidth effectively addresses the issue of radiation direction deflection.To further improve the performance,the unit is composed of a 2x2 periodically arranged antenna array.Based on the physical test results,the impedance bandwidth was found to be 35.4%(28.8-41.2GHz)while the AR bandwidth was 26.8%(28.8-37.7GHz).The radiation direction showed significant improvement,and the cross-polarization was lower.The slot-coupled fed wideband ME-dipole antenna is designed with quarter-circle microstrip lines and cross slots of unequal lengths,which enable the antenna to achieve circular polarization(CP).Additionally,the tangential angle of the electric dipole and the asymmetric distribution of the magnetic dipole further improve the CP performance.The 2x2 antenna array is used as a subarray and arranged in a periodic manner to form a 16-unit antenna array through sequential rotation.This design achieves a concentrated radiation direction and widens the AR bandwidth.The simulation results indicate that the S11 value is less than-10 d B within the frequency range of 20 to 35 GHz.The antenna array also possesses a wide axial ratio(AR)bandwidth of 27.2%(22.2-29.2GHz)and a peak gain of 16 d Bic.These characteristics make the antenna array ideal for meeting the requirements of the current millimeter band wireless development,due to its broadband,high gain and wide AR capabilities. |
PDF Full Text Request