Research And Design Of The Low-profile Magneto-electric Dipole Antenna

Wireless communication equipments are being upgraded continuously with the rapid expansion of wireless communication technology such as Bluetooth,WCDMA and LTE,etc.Moreover the antenna,as the front-end of RF equipments,is a vital factor that influence the quality of wireless communication.Designing of the low-profile and high-performance antenna is helpful for enhancing the performance of wireless communication equipments.So,two types of low-profile magneto-electric dipole antenna based on the magneto-electric antenna theory is studied and designed in this dissertation:The first is a microstrip-type end-fire magneto-electric dipole antenna of which the rectangular patch works as an electric dipole and the hollow triangular patch works as a magnetic dipole,a good compensation of radiation pattern is achieved.A high front-to-back ratio of more than 19dB is achieved.The cross polarization of the antenna is lower than-40dB,and a maximum gain of 4.93 dBi is achieved,the impedance frequency band is from 2.281 GHz to 2.536GHz(S11<-10dB)which covers the ISM-2.4GHz band.The proposed antenna is similar to the conventional microstrip antenna in shape,but its cross-polarization level is much lower.The second is a low-profile wideband magneto-electric dipole antenna.The antenna consists of a pair of metal patches,two metal walls that connect the metal patches and the metal ground,a slotted U-shaped reflector and a ?-shaped feeding structure.The two metal patches works as an electric dipole,the metal walls and the metal ground between them together with the ?-shaped feeding structure equals to a magnetic dipole.The antenna bandwidth is wide because of the properly designed?-shaped feeding structure.The current path of the antenna is lengthened by the slots on the metal ground,as a result,the profile height of the antenna is reduced.A greater antenna gain is achieved because of the U-shaped reflector.The antenna achieved a maximum gain of 8.83dBi,a cross-polarization level of lower than-39dB,and a front-to-back ratio of more than 20dB.The impedance frequency band is from 1.824GHz to 2.877GHz(S11<-10dB)which covers plenty of frequency bands including LTE1900,WCDMA band and LTE2300,etc.The prototype of the two proposed antennas are fabricated and tested.The acceptable results obtained between the measured and tested results proves the feasibility of the proposed antenna designing schemes.