Design Of THz-wave Microstrip Antenna Based-on Dual-surfaced Multiple Split-ring Resonators

Terahertz-wave(THz-wave)is the electromagnetic wave operating at 0.1-10 THz frequency band with the corresponding wavelength range of 0.03-3 mm.In recent years,the THz frequency band has attracted wide attention from many researchers due to its characteristics of broadband and high-speed transmission.As one of the key front-end devices taking part in the future THz frequency band communication system,the THz-antenna normally has the structure of rectangular horn or reflectors in existing systematic simulation or experimental research,instead of planar microstrip design.In this thesis,the structure of Split-Ring Resonators(SRR)has been chosen as the basic unit of the proposed microstrip antenna in focusing frequency band.According to the known THz-wave propagation loss caused by rain and oxygen attenuations in space,finally the goal frequency band of around300 GHz has been selected for the proposed THz-wave microstrip antenna design based on Dual-surfaced Multiple SRR(DMSRR)structures.In this optimization procedure,many attempts have been tried to do the research on influences of different structural parameters on antenna performance systematically.The main research work and innovation point in this thesis are as follows:1.By employing the electromagnetic-field full-wave numerical computational method based-on Finite-Integral Time-Domain(FITD)algorithm,the antenna based-on DSMRR structures and fed with microstrip transmission lines has been optimized and designed.The influence of the structural parameters,such as split-ring gap width,ring width,ring spacing and ring number,on the antenna resonant characteristics are obtained.From the results analyses,it has been found that the resonant frequency of the proposed antenna would step down with the decreasing of the ring width and the ring spacing.Also,the ring number has significant nonlinear affect,otherwise the split-ring gap width has unobvious impact on the resonant frequency.2.The proposed dual-surfaced triple split-ring resonators THz microstrip antenna has been optimized to achieve the central resonant frequency of around 300 GHz,the bandwidth of around 35 GHz,and the antenna gain of around 3.1 d Bi.As for the limitation of fabrication and test conditions for THz-waveband devices,there is a size-scaling method proposed in this thesis,to scale up the antenna structure with equal proportion changing from 300 GHz to 2.4 GHz resonant frequency.Through the fabrication and test process for the scale-up size antenna it has been found that the experimental results have shown good agreement with the simulated ones,so as to indirectly verify the method feasibility of applying the scaling effect on designing the target DMSRR THz microstrip antennas.3.To improve the antenna gain,working bandwidth,and even achieve the multi-band operation,the array arrangement for the above DMSRR with the microstrip transmission line feeding network have been tried.Here in this thesis,a2×2 microstrip antenna array composed by the above dual-surfaced triple split-ring resonators structure has been proposed.In the same way to do the verification work,the 2×2 microstrip antenna array has also been scaled up and fabricated at the central resonant frequency of around 2.45 GHz.It can be seen that the simulated results agree well with the experimental results.