A plasma column excited by a surface wave can act as a plasma antenna. Experiments are carried out to study the current and conductivity distributions, field, power patterns, directivity and efficiency of such a plasm...A plasma column excited by a surface wave can act as a plasma antenna. Experiments are carried out to study the current and conductivity distributions, field, power patterns, directivity and efficiency of such a plasma antenna. In addition, an equivalent metallic copper antenna is built up and its antenna parameters are compared with that of the plasma antenna. Our findings indicate that the power content in the harmonics of the plasma antenna is more prominent as compared to the copper antenna （which only generates a fundamental frequency）. However, the power patterns for both antennae are quite similar. To provide a more qualitative understanding regarding the generation of harmonics in the field of the plasma antenna, a bi-spectral analysis is performed to study the nonlinear interactions in the current fluctuations. Some specific features of the plasma antenna are investigated in our study, which may enhance the application prospect of the plasma antenna with respect to the conventional metallic antenna.展开更多
Several antennas based on cylindrical array and uniform hexagonal array are designed and fabricated on flexible substrate-Teflon.To validate the designed prototypes,the antennas are fabricated and their performance is...Several antennas based on cylindrical array and uniform hexagonal array are designed and fabricated on flexible substrate-Teflon.To validate the designed prototypes,the antennas are fabricated and their performance is analyzed.The highlight scheme is to improve the signal performance and electromagnetic field distribution by appropriately changing the parameters of the antennas array,signal frequencies,and steering angles.The proposed antennas array is capable of applying shaping radiation band technique to generate tunable power and radiation domain.The distribution of the field,and the bit-error-rate transmigration coefficient characteristics are measured.The results show that the proposed scheme can achieve better performance by searching the optimal parameters of antenna array.展开更多
Due to the consideration of safety,non-contact measurement methods are be-coming more acceptable.However,massive measurement will bring high labor-cost and low working efficiency.To address these limitations,this pape...Due to the consideration of safety,non-contact measurement methods are be-coming more acceptable.However,massive measurement will bring high labor-cost and low working efficiency.To address these limitations,this paper introduces a deep learning model for the antenna attitude parameter measurement,which can be divided into an an-tenna location phase and a calculation phase of the attitude parameter.In the first phase,a single shot multibox detector(SSD)is applied to automatically recognize and discover the antenna from pictures taken by drones.In the second phase,the located antennas’fea-ture lines are extracted and their attitude parameters are then calculated mathematically.Experiments show that the proposed algorithms outperform existing related works in effi-ciency and accuracy,and therefore can be effectively used in engineering applications.展开更多
文摘A plasma column excited by a surface wave can act as a plasma antenna. Experiments are carried out to study the current and conductivity distributions, field, power patterns, directivity and efficiency of such a plasma antenna. In addition, an equivalent metallic copper antenna is built up and its antenna parameters are compared with that of the plasma antenna. Our findings indicate that the power content in the harmonics of the plasma antenna is more prominent as compared to the copper antenna （which only generates a fundamental frequency）. However, the power patterns for both antennae are quite similar. To provide a more qualitative understanding regarding the generation of harmonics in the field of the plasma antenna, a bi-spectral analysis is performed to study the nonlinear interactions in the current fluctuations. Some specific features of the plasma antenna are investigated in our study, which may enhance the application prospect of the plasma antenna with respect to the conventional metallic antenna.
基金Projects(61803390,61501525)supported by the National Natural Science Foundation of ChinaProject(61927803)supported by Major Scientific Instrument Development Project of National Natural Science Foundation of China。
文摘Several antennas based on cylindrical array and uniform hexagonal array are designed and fabricated on flexible substrate-Teflon.To validate the designed prototypes,the antennas are fabricated and their performance is analyzed.The highlight scheme is to improve the signal performance and electromagnetic field distribution by appropriately changing the parameters of the antennas array,signal frequencies,and steering angles.The proposed antennas array is capable of applying shaping radiation band technique to generate tunable power and radiation domain.The distribution of the field,and the bit-error-rate transmigration coefficient characteristics are measured.The results show that the proposed scheme can achieve better performance by searching the optimal parameters of antenna array.
文摘Due to the consideration of safety,non-contact measurement methods are be-coming more acceptable.However,massive measurement will bring high labor-cost and low working efficiency.To address these limitations,this paper introduces a deep learning model for the antenna attitude parameter measurement,which can be divided into an an-tenna location phase and a calculation phase of the attitude parameter.In the first phase,a single shot multibox detector(SSD)is applied to automatically recognize and discover the antenna from pictures taken by drones.In the second phase,the located antennas’fea-ture lines are extracted and their attitude parameters are then calculated mathematically.Experiments show that the proposed algorithms outperform existing related works in effi-ciency and accuracy,and therefore can be effectively used in engineering applications.
