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A C-band broadband polarization reconfigurable antenna array is introduced to enhance the spectrum efficiency and transmission capacity. This antenna array provides four kinds of polarization switching modes, including horizontal-polarization, vertical-polarization, left circularly-polarization and right circularly-polarization. Simulation results are presented and discussed, the performance verify...
An X-band wide-slot linear array with protrusion for one dimensional wide-angle scanning is presented. The antenna element is based on a normal printed rectangular wide-slot structure, which is then folded to form a compact cavity to achieve a wide beamwidth in E-plane while retains its wide band characteristic. Metal protrusions are set between the elements in the array to improve the antenna active...
In this paper, a circular truncated cone slot antenna radiating circular polarization conical beam is presented. The circular polarization property is realized by perpendicular slots cut on the outer conductor of the circular truncated cone, and the direction of the conical beam mainly depends on the lilt angle of the outer conductor as well as proper arrangement of the position of two slot arrays...
This paper reports the design of a novel dual-polarized waveguide antenna array antenna for Ku-band (Rx: 12.2512.75GHz; Tx: 14.0–14.5GHz) satellite communications. The horizontal polarized antenna is a ridged waveguide V-shaped slots antenna, which has very low cross-polarization. The vertical-polarized antenna is a longitudinally-slotted ridge waveguide antenna, which has broadband character and...
We present a simple method to minimize the gain roll-off of the Rotman lens antenna with wide scans. Phase gradient transmission lines are used to neutralize a precipitous drop in the power efficiency of Rotman lens when the scan angle increases. To validate the proposed method, a Rotman lens antenna at X band with 8 beam ports and 9 array ports are designed and simulated. The results show that the...
In this paper, a novel single-pole-double-throw (SPDT) switch based on the ring structure is proposed, which can be applied in the multi-beam antenna arrays system. Different from the conventional SPDT switch, its reliability can be enhanced further for it does not involve any state of total reflection. Moreover, it can also perform as a power divider under the proper bias voltage.
The multi-mode OAM beams generated by a circular phased antenna array are always in divergent directions, which restrict the practical application. To relieve this drawback, the Fabry-Perot (FP) cavity is employed to meliorate the beam orientation, and enhance the directivity of the OAM array. The Fabry-Perot cavity consists of a ground plane, an air cavity and a partially reflecting surface (PRS)...
An ultra-thin water metamaterial in the shape of a fishnet structure is designed and analyzed. It is theoretically shown that coherent perfect absorption can be achieved in such a metamaterial, where the reflection and transmission coefficients have same amplitudes and nearly 180° phase delay. Moreover, the coherent absorptivity of the water metamaterial can be manipulated from 0.59% to 99.99% by...
A three-port reconfigurable network for muti-polarization antenna applications is presented. Five power routing states (1:0), (0:1), (1:1), (1: j) & (1:-j) is provided with 9 PIN diodes. The high frequency parasitic effect of the PIN diodes involved in impedance matching is accurately considered. Good matching and isolation performance is verified at the design frequency 5.2 GHz by using the co-simulation...
We present the design of a compact microstrip filtering power dividers by utilizing the coupling between adjacent resonators. For the purpose of effectively reducing the circuit area and achieving a good isolation, four novel resonators are precisely designed and arranged. Numerical simulation shows that a filtering power with size as compact as 0.16 λg by 0.16 λg can achieve a high isolation over...
The antenna structure generating orbital angular momentum (OAM) beam with small divergence angle is described in this paper. Luneberg lens, always used to generate high gain beam, is utilized in this structure to focus the OAM beam generated by the source. Luneberg lens is discretized into layers. With simulations, the OAM beam's divergence angle with 19 degree is successfully decreased to 5 degree,...
A wideband and wide-angle scanning circularly polarized array with low profile is introduced. The proposed array is composed of three annular sub-arrays with tilted elements and a ripple-shaped ground plate. A case with 64 elements is designed and simulated. The simulation results demonstrates that array scanning gain fluctuations less than 2.26 dB at the center frequency and 3 dB in the operation...
In this paper, a T-shaped feed structure is presented that enhances the performance of a polarization diversity antenna. It is a four-port network that consists of two input ports and two output ports. The −10 dB relative impedance bandwidth is 6.64 GHz from 2.31GHz to 8.95 GHz, i.e., 117.9% and the isolation is at least 29.7 dB within the same band. Furthermore, the insertion loss is less than 0...
This paper presents a wideband circularly polarized array with improved gain and sidelobe level by using bowl-shaped reflector with high impedance surface (HIS). The proposed array is composed of four crossed dipole elements which have a sequentially rotated configuration. The high impedance surface is realized by applying corrugated surface to the bowl-shaped reflector. The simulation results show...
A novel direction finding method with the time modulated linear array (TMLA) is proposed and verified, by establishing the relationship between the incident angle and the generated harmonic characteristic matrix (HCM). The principle is that the generated HCM because of the periodical modulation varies with the incident direction of the RF signal. Compared to the existing direction finding method,...
In this paper, a novel low-profile circularly polarized crossed dipole antenna operating at UHF band, with small dimensions of 180 mm × 160 mm × 4 mm ( 0.22 λ × 0.20 λ × 0.005 λ) where λ is the wavelength corresponding to resonant frequency 370MHz, is proposed. Meandering lines are designed to reduce the size of the antenna. To achieve circularly polarized radiation pattern, a feeding network composed...
The optimized metasurface layer is introduced into antenna design, which is generated by dividing a 2-D rectangular area into some grids, then the initial 2-D chromosome population is produced randomly. The size of population is the number of grids, “1” represent the metallized areas and “0” represent the areas without metal. Based on this model, we optimized two parasitic metasurface layer under...
The gain medium coated cylindrical nano particle is presented, in which the core is filled by Ag and obey Drude model, the shell is the gain medium, which was silica doped with rare earth (erbium Er3+) ions, and it obeys the Lorentz model for the relative permittivity. In the optical plane wave, we compared the silver coated gain medium cylindrical nano particle and the gain medium coated Ag cylindrical...
A discrete dielectric reflectarray for generating mixed-mode OAM radio waves is presented. The reflectarray is introduced to transform the spherical wave emanating from the feed into a vortex beam after reflection. Through perforating the flat substrate with holes of various diameters, an azimuthal variation of effective permittivity is obtained and the corresponding azimuthal phase-compensation can...
A dual-mode (l=-1 and 3) orbital angular momentum (OAM) antenna array is described in this paper. Gene Algorithm (GA) method is used to optimize the excitation of antenna array for separating different OAM mode in different beam lobe. The CST Microwave Studio is also used to simulate the 12 horn elements antenna array excited by the complex amplitude which is optimized by the GA. It is successful...
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