| 5G technology has advanced by leaps and bounds in recent years.China has selected24.75GHz-27.5GHz and 37GHz-42.5GHz as alternative frequency bands for 5G millimeter wave technology.At the same time,60GHz band wireless short range communication technology is also attracting attention.Millimeter wave technology has become one of the key technologies in5G communication because of its high data transmission rate and low delay.Dielectric resonator antennas have high application value in modern millimeter wave communication systems because of their high radiation efficiency,low surface wave loss,wide bandwidth,light weight,small size and easy excitation.The number of wireless communication devices and users continues to grow,requiring communication systems to have wider bandwidth to meet the needs of modern communication systems.According to the antenna bandwidth index,this paper studies the technology of improving the bandwidth of dielectric resonator antenna,and further improves the performance of dielectric resonator antenna.The main contents are as follows:（1）A cylindrical wideband dielectric resonator antenna and its 4×1 array antenna are proposed based on the nested structure of K-band and Ka-band microstrip and cross-slot coupling feeds.The antenna is fed by coupling microstrip line and cross slot to increase bandwidth and produce circular polarization.By using cylindrical dielectric resonators nested with different dielectric constants to improve the impedance bandwidth,we finally realized a millimeter wave broadband dielectric resonator antenna with an operating frequency band of23.75GHz-29.35GHz,impedance bandwidth of 21.9%,gain of 6.43d Bi and axial ratio bandwidth of 7.57%.The correctness of the design is verified by comparing the measurement and simulation data.The advantage of the antenna is that it works in the millimeter wave band,and has a wide bandwidth and high gain,which can meet the current needs of 5G millimeter wave communication applications.In order to broaden the AR bandwidth,a 4×1 array based on the shunt feed network is designed to achieve 23%AR bandwidth and gain of 11d Bi.（2）A kind of millimeter-wave wideband dielectric resonator antenna based on MIMO technology is proposed.The antenna uses two inverted L-shaped microstrip wires connected by two ports to respectively stimulate two cylindrical dielectric resonators to radiate energy.A rectangular slot is etched on the ground surface below the middle position of the two microstrip wires to improve impedance bandwidth and isolation.Finally,a new antenna with a center frequency of 33.31GHz is obtained.The impedance bandwidth of port 1 is 54.01%（20.90GHz-38.89 GHz）,and that of port 2 is 55.27%（20.89 GHz-39.3 GHz）.The maximum gain of broadband dielectric resonator antenna is 14.22d Bi.In order to improve the isolation,A rectangular slot is etched on the ground surface below the middle of the two microstrip lines,and the antenna isolation is successfully raised below-15d B.The passband of the antenna covers the millimeter wave band and has a good application prospect.（3）A U-band T-shaped high gain broadband dielectric resonator antenna based on SIW feed is proposed.The antenna uses substrate integrated waveguide technology coupled to T-shaped resonator to stimulate the T-shaped resonator,through the SIW to concentrate the energy to improve the gain,through the T-groove coupled to the T-shaped resonator to produce higher order mode HEM211to improve the gain and impedance bandwidth,and finally achieve a center frequency of 60.11GHz.A T-shaped wideband dielectric resonator antenna with impedance bandwidth of 21.09%（53.32GHz-66GHz）and maximum gain of 9.46d Bi. |
