Dual-Channel Communication of Column Plasma Antenna Excited by a Surface Wave——Actualization and Simulation of Radiation Pattern

Along with the introduction of the concept of dual-channel communication,we utilized the finite-difference time-domain（FDTD） method to simulate and measure the radiation pattern under certain plasma densities and plasma collision frequencies.Results show that under certain settings,the radiation pattern of a plasma antenna resembles that of a metallic antenna.In contrast to a metallic antenna,a plasma antenna possesses other functionalities,such as dynamic reconfiguration and digital controllability.The data from simulation are similar to the measurement results,indicating that column plasma antenna can realize dual-channel communication.This work confirms the viability of realizing dual-channel communication by column plasma antenna,which adds a new but promising method for modern intelligent communication.

Reconfigurable Pattern Patch Antenna for Mid-Band 5G:A Review

New requirements in communication technologies make it imperative to rehash conventional features such as reconfigurable antennas to adapt with the future adaptability advancements.This paper presents a comprehensive review of reconfigurable antennas,specifically in terms of radiation patterns for adaptation in the upcoming Fifth Generation(5G)New Radio frequency bands.They represent the key of antenna technology for materializing a high rate transmission,increased spectral and energy efficiency,reduced interference,and improved the beam steering and beam shaping,thereby land a great promise for planar antennas to boost the mid-band 5G.This review begins with an overview of the underlying principals in reconfiguring radiation patterns,followed by the presentations of the implemented innovative antenna topologies to suit particular advanced features.The various adaptation techniques of radiation pattern reconfigurable planar antennas and the understanding of its antenna design approaches has been investigated for its radiation pattern enhancement.A variety of design configurations have also been critically studied for their compatibilities to be operated in the midband communication systems.The review provides new insights on pattern reconfigurable antenna where such antennas are categorized as beam steering antenna and beamshaping antennas where the operation modes and purposes are clearly investigated.The review also revealed that for mid-band 5G communication,the commonly used electronic switching such as PIN diodes have sufficient isolation loss to provide the required beam performance.

Mathematical Simulating Model of Phased-Array Antenna in Multifunction Array Radar

A mathematical simulating model of phased-array antenna in multifunction array radar has been approached in this paper, including the mathematical simulating model of plane phased-array pattern, the mathematical simulating model of directionality factor, the mathematical simulating model of array factor, the mathematical simulating model of array element factor and the mathematical simulating model of beam steering.

Optimal Design of Wireless Power Transmission Systems Using Antenna Arrays

Three design methods for wireless power transmission(WPT)systems using antenna arrays have been investigated.The three methods,corresponding to three common application scenarios of WPT systems,are based on the method of maximum power transmission efficiency(MMPTE)between two antenna arrays.They are unconstrained MMPTE,weighted MMPTE,and constrained MMPTE.To demonstrate the optimal design process with the three methods,a WPT system operating at 2.45 GHz is designed,simulated,and fabricated,in which the transmitting(Tx)array,consisting of 36 microstrip patch elements,is configured as a square and the receiving(Rx)array,consisting of 5 patch elements,is configured as an L shape.The power transmission efficiency(PTE)is then maximized for the three application scenarios,which yields the maximum possible PTEs and the optimized distributions of excitations for both Tx and Rx arrays.The feeding networks are then built based on the optimized distributions of excitations.Simulations and experiments reveal that the unconstrained MMPTE,which corresponds to the application scenario where no radiation pattern shaping is involved,yields the highest PTE.The next highest PTE belongs to the weighted MMPTE,where the power levels at all the receiving elements are imposed to be equal.The constrained MMPTE has the lowest PTE,corresponding to the scenario in which the radiated power pattern is assumed to be flat along with the Rx array.

A Substrate Integrated Waveguide Based Filtenna for X and Ku Band Application

In this paper Substrate Integrated Waveguide-basedfiltenna operating at Ku band is proposed.The model is designed on a low loss dielectric substrate having a thickness of 0.508 mm and comprises of shorting vias along two edges of the substrate walls.To realize a bandpassfilter,secondary shorting vias are placed close to primary shorting vias.The dimension and position of the vias are carefully analyzed for Ku band frequencies.The model is fabricated on Roger RT/duroid 5880 and the performance characteristics are measured.The proposed model achieves significant impedance characteristics with wider bandwidth in the Ku band.The model also achieves a maximum gain of 7.46 dBi in the operating band thus making it suitable for Ku-band applications.Substrate Integrated Waveguide(SIW)Structures possess most of the advantages over conventional radiofrequency waveguides since they have high power management capacity with self-consistent electrical shielding.The most noteworthy advantage of SIW,it can able to integrate all the components on the same substrate,both passive and active components.

Method to reconnoiter pulse amplitude train for phased array radar based on Hausdorff distance

This paper presents a method to estimate beam pointing of phased array radar by the pulse amplitude train, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, the antenna patterns modeling of the phased array system is exploited to build the radar sweeping model and the signal propagation model. Secondly, the relationship between the variation of the radiated power and the antenna beam pointing angles in the given airspace is analyzed. Based on the above two points, the sample with obvious amplitude characteristics of the pulse amplitude train can be screened out after detecting the train peaks. Finally, the sample is matched to the subsequent pulse amplitude train based on the Hausdorff distance. The proposed methods have less prior knowledge and higher efficiency and are easier to process. By cross correlating the sample of the pulse amplitude train with the sample data of the antenna follow-up radiation, the probability of detection of the beam pointing direction becomes larger in case that the subsequent antenna beam returns to the specific position.

Pattern synthesis optimization of 3-D ODAR based on improved GA using LSFE method

Pattern synthesis in 3-D opportunistic digital array radar(ODAR) becomes complex when a multitude of antennas are considered to be randomly distributed in a three dimensional space.In order to obtain an optimal pattern,several freedoms must be constrained.A new pattern synthesis approach based on the improved genetic algorithm(GA) using the least square fitness estimation(LSFE) method is proposed.Parameters optimized by this method include antenna locations,stimulus states and phase weights.The new algorithm demonstrates that the fitness variation tendency of GA can be effectively predicted after several "eras" by the LSFE method.It is shown that by comparing the variation of LSFE curve slope,the GA operator can be adaptively modified to avoid premature convergence of the algorithm.The validity of the algorithm is verified using computer implementation.

Study of Electromagnetism Compatibility of Bleeper Station

Transmitted power will decrease, cross-modulate distortion and inter-modulate distortion will be caused and antenna pattern will shift if transmitted antennas are fixed together. All these will lead to the alteration of area coverage. According to the basic theory of electromagnetism compatibility a computer model is established. We do some quantitative analysis of the problems above and give total number, arrangement mode and distance between antennas of bleeper station that operate at 150 MHz. The relation of these factors above are also given. All these are basis of the arrangement of antenna group of bleeper station.

A NOVEL NULLING ALGORITHM IN THE SUBARRAY OF A LARGE ARRAY

Forming nulls in the radiation pattern of an antenna is to suppress the interference from certain directions or to cancel desired signals. This letter presents an effective method based on the Gram-Schmidt orthogonal algorithm for fonning nulls in the subarray of a large array. The theory and realizing methods are discussed, and the corresponding fonnulas are derived in details. The simulation results are given to demonstrate the feasibility, the availability and the quick-convergence of the presented method.

Multi-Step Amplitude Quantization for Ultralow Sidelobe Phased Arrays by Direct Optimization Synthesis

In this paper, a new amplitude quantization synthesis method for ultralow sidelobe phased arrays is proposed, which is based on the constrained nonlinear optimization algorithm. By introducing a set of critical constraint conditions into the optimization model, we can directly quantize the amplitude distribution instead of replacing it with a continuous equivalent aperture antenna. The mutual coupling and the element patterns are also considered in the quantization synthesis. Finally, some array simulation results are given to show the effectiveness of the method.

PO Analysis for RCS of Nonorthogonal Dihedral Corner Reflectors Coated by RAM

The backscattering radar cross section (RCS) of nonorthogonal dihedral corner reflectors coated by RAM (radar absorbing materials) is formulated by the method of PO (physical optics), where singly, doubly, and triply reflected contributions are considered. The final expressions are analytical and allow for the incidence nonperpendicular to the fold axis of the reflector. The results are compared with ones of MoM (method of moment), which shows that the trend of backscatter pattern of the dihedral corner reflector can be well predicted by this method.

Design of hexagon microstrip antenna for vehicle-to-vehicle communication

Considering the shortcomings of the existing vehicle-to-vehicle（V2V） communication antennas, this paper proposes a regular hexagon broadband microstrip antenna. By loading shorting pins and etching V-shape slots with different size at each angle of the regular hexagon patch, it realizes impedance matching and obtains better impedance bandwidth. The simulated results show that the relative bandwidth of this antenna reaches 35.55%, covers the frequency band of 4.74 GHz to 6.79 GHz. The antenna acquires an omni-directional radiation pattern in the horizontal plane whose out of roundness is less than 0.5 d B. In addition, the antenna is manufactured and tested, whose tested results are basically consistent with simulated results. Because the height of antenna is 3 mm, it is easy to be hidden on roof of a vehicle for V2 V communication.

Analysis of airborne antenna using a FEM-UTD hybrid method

In this paper,the near-field vector components were used to combine the FEM method and the uniform-geometrical theory of diffraction(UTD)method for analyzing phased array antenna mounted on an airborne platform.First,HFSS,a set of software based on finite element method(FEM),was utilized to find the near-field vector components of the phased array antennas,and then these vector components were used as the source of the UTD method to get the disturbed radiation pattern.Numerical results show that the hybrid of the two methods not only extends the use of the UTD program,but also effectively solves this type of challenging problems.

Recent Advances in Reconfigurable Antennas at University of Technology Sydney

This paper presents an overview of the recent advances in reconfigurable antennas for wireless communications at University of Technology Sydney.In particular,it reports our latest progress in this research field,including a multi-linear polarization reconfigurable antenna,a pattern reconfigurable antenna with multiple switchable beams,and a combined pattern and polarization reconfigurable antenna.