Research On Dual-band Dielectric Resonator Antenna

With the advancements in communication technology,there is an increasing demand for dual-band antennas that offer features such as miniaturization,wide bandwidth,high gain,and low cost.The dielectric resonator antenna（DRA）is a compact and low-loss antenna,while the dielectric Fabry-Perot resonator antenna（FPRA）has a high gain.In this thesis,four dual-band antennas with varying frequency ratios were designed and analyzed using DRA and FPRA.The first antenna is a finite frequency ratio stacked dual-band DRA that operates in the 2.8GHz and 4.8GHz bands with a frequency ratio of less than 3.This antenna has a compact structure and a wide impedance bandwidth suitable for 5G communication systems.The second antenna proposed is a new probe-fed wideband cylindrical dual-band DRA with a frequency ratio of 1:5.The antenna consists of a microwave hollow cylindrical DRA on a square ground plane and a cylindrical DRA,forming an FPRA inside the hollow cylindrical Dielectric Resonator（DR）.The two bands are fed by vertical strips that excite the HEM_11δmode of the DRA.This antenna has a wide impedance bandwidth for both low and high frequencies.The third antenna is a novel type of large-frequency ratio rectangular hollow dual-band DRA with a frequency ratio of 1:10.It is achieved by a new dual-band DRA-FPRA antenna constructed of a hollow rectangular DRA.The low band DRA is fed by a strip excitation on the DRA sidewall,while the high-frequency band FPRA is fed through the WR-34 waveguide.The low band DRA operates in TE_11δmode,and the high-frequency band FPRA resonance is in dielectric Fabry-Perot Resonator（FPR）mode.The significant advantage of this design is that the integration of DRA with FPRA does not affect the performance of DRA.Lastly,a new large frequency ratio wideband dual-frequency antenna design with a frequency ratio of 1:10 was developed to improve the frequency coverage of low and high-frequency bands.The antenna operates in DRA and FPRA modes in low and high frequencies,respectively,sharing the same dielectric and divided into upper and lower parts.The lower part is a hollow cylindrical DR of a single medium,and the upper part includes three DRs with different dielectric constants.The low band is fed through a vertical strip,and the high-frequency band is fed by the WR-34waveguide.This antenna provides a wide impedance bandwidth and gains bandwidth in two bands with a high-frequency ratio.