Design Of A Novel Dual-band Microstrip Antenna And Study Of Graphene-based Antenna

Microstrip antenna has widely applied in biomedicine,radar and its detection,space science,satellite navigation,mobile devices etc.with its excellent performance.This paper has combined the advantages of the disk and the concentric ring for dual-band microstrip antenna which is operated in TM₁₁ mode and TM₁₂2 mode,respectively.The antenna is designed for working in WLAN 2.45 GHz and 5.3 GHz band.However,spectrum resources become valuable with the development of communication technology.The terahertz frequency which is located between electromagnetism and optics and has been attracted much attention.A novel graphene-based artificial magnetic conductor antenna in terahertz band has discussed in this paper presents.This work can be summarized as follows:?1?A novel dual-band microstrip antenna using a ring and concentric disk which is worked at WLAN has been proposed.The mutual loading effect between the disk with the concentric ring and the influence of the feed port and edge effects have been considered.The maximum working frequency range using the disk and ring antenna is discussed.It is found that the mutual loading perturbs the resonant frequencies and thus the outer and inner radii of the ring and the radius of the disk calculated from the cavity models need to be slightly adjusted.Based on the change of the antenna radiation characteristics,the reasonable radius range of the disk and ring have got through HFSS simulation results.?2?How to increase the impedance of the ring which is operated in high order mode is discussed.It was further found that the traditional U-slot technique and E slot cannot be used to enhance the impedance bandwidth of the circular ring microstrip antenna effectively.With the effects of two rectangular slots,the ring antenna bandwidth increases nearly twice and meets the WLAN communication standards.?3?The effects of differently-driven ports for the ring which is operated by higher mode are discussed.Due to the introduction of the differential signal,ring of the antenna coupling mode is inhibited.It is shown that the differentially-driven ring has an improved current distribution,a better impedance matching,and a double impedance bandwidth.Moreover,a higher gain is obtained for the disk.?4?A novel graphene-based artificial magnetic conductor antenna in terahertz band has been proposed.A complementary structure is used and can be tuned by applying a bias voltage where the conductivity of graphene is tunable.An equivalent circuit model is then given to analyze the elements of the complementary structure.Both the simulated and analytical reflection phase results are presented with some agreements in different chemical potential.Further,the characteristics of a dipole antenna which is placed over the12*12 units graphene-based AMC is analyzed.