Research On Polarization And Frequency Reconfigurable Dielectric Resonator Antenna

With the rapid development of wireless communication technology,the market demand for communication in different frequency bands is increasing,and the number of antennas in communication systems is increasing,too.The increase in the number of antennas results in the large size of the wireless communication system equipment,serious electromagnetic interference between the antennas and poor communication quality.Multi-band and reconfigurable antenna technology can reduce the number of antennas in the system and become one of the research hotspots in the field of antenna design.The dielectric resonator antenna is widely used due to its small size,high efficiency,and wide bandwidth.This paper researches the multi-band and reconfigurable dielectric resonator antennas.The specific work is as follows:1.A three-band dual-polarized dielectric resonator antenna is designed.The three-band dual-polarization performance is achieved and and bandwidth is broadened by studying the influence of the L-shaped slit and the circular hole on the ground of the dielectric resonator antenna.Through embedding slots and holes on the ground plane,horizontally rotated current is formed on the ground.Combining the fields of the fundamental mode in DRA and horizontally rotated current on the ground,an omnidirectional circularly polarized radiation is formed in the first band.Meanwhile,the slots and holes in the ground plane can cause perturbation to resonator to enlarge the second band.The third frequency band is realized by the higher order mode of resonator.Through the optimization of the parameters of slots and holes,the antenna is designed,processed and tested.2.A wideband polarization reconfigurable dielectric resonator antenna is designed.The reconfigurable microstrip line is controlled by PIN diodes.The resonator is fed by the microstrip line through an annular slot and the HEM₁₁?modes with different polarization and phase are excited in the resonator,which enable antenna to achieve wideband polarization reconstruction between liner polarization,left-hand circular polarization,and right-hand circular polarization.Through the optimization of parameters such as the ring gap,the antenna is designed,processed and tested.Compared with the previously reported polarization reconfigurable antennas,the circularly polarized operating bandwidth of this antenna is significantly improved when the dimensions are similar.3.A frequency reconfigurable dielectric resonator antenna is designed.The reconfigurable microstrip line is controlled by PIN diodes.Frequency reconfigurable is achieved by exciting various resonant modes within the dielectric resonator at different locations and differently shaped slots.Under the different combinations of PIN diodes,the microstrip through the semi-annular slits,rectangular slits and circular slits excites the quasi-HE₁₁?mode,HE₂₁?mode and EH₃₁₁₊?mode of the dielectric resonator,respectively.Thereby,the antenna can work in three separate frequency bands.Through the optimization of parameters such as semi-annular slits,rectangular slits and circular slits,the antenna is designed,processed and tested.