Design And Research Of Dual-frequency Resonator Antenna

Resonator antenna is a sort of high-gain antenna which has advantages of simple structure,low profile and simple feeding.Resonant antenna consists of three parts,feeding antenna,ground and partially reflective surface(PRS).Several dual-band resonant antennas are proposed and designed in the paper,including based on dielectric-slab and based on frequency selective surface.The main work in this paper can be summed up as follows:1.The resonator antenna is analyzed with a ray-tracing model and the main parameters are concisely derived.A method for designing dual-band resonator antenna which is based on invertible reflection phase gradient is introduced.2.Design and implementation of the dual-band resonator antenna based on dielectric slab is introduced.Multilayered Media Theory is introduced which can calculate the reflection of multi-dielectric-slabs.And the transmission-line theory and Smith Chart are applied in the design of the PRS.Then a dual-band resonator based on three dielectric slabs is proposed which can achieve wonderful pattern by low-permittivity slab.The design is validated by a practical antenna design and corresponding experiments.3.Some improvements in dual-band resonator antenna based on dielectric slab is proposed.Firstly a dual-band resonator antenna based on two dielectric slab is designed,and the antenna can reach a lower profile.Then a PRS made of three lays of dielectric slabs whose frequency ration can be flexible adjustment.Simulation proved that the antenna loaded with the PRS whose frequency ratio is 1.38 to 1.8 works well.4.Dual-band resonator antenna based on FSS is introduced.FSS replaces the structure made of dielectric slabs as PRS,generally lowing the profile,increasing the degree of freedom and eliminating the effects of dielectric constants and thicknesses of the slab.Firstly a single layer and double side ring FSS is applied to dual-band resonator antenna,and the antenna can achieve high gain at two frequencies if the frequency ratio is less than 1.3.Then the configuration of ring on the bottom side is changed,and the resonator antenna loaded with the new FSS can achieve a bigger ratio.The design is validated by a practical antenna design and corresponding experiments.