Design of a Bifocal Single Reflectarray Antenna with Improving Beam Scanning Performance

2015 ◽  
Vol 9 (1) ◽  
pp. 200-207
Author(s):  
Yan Qu ◽  
Chenjiang Guo ◽  
Wencan Peng ◽  
Jun Ding ◽  
Yuteng Gao ◽  
...  

A novel scheme is introduced to design the high gain beam scanning reflectarray antennas for limited scan range application. At first, various existing schemes for beam scanning reflectarray antennas design are reviewed and it is concluded that as a convenient design scheme, the feed displacement technique is preferred for limited scan range applications. In order to improve the scan range, a bifocal single reflector aperture phase is introduced for reflectarray aperture phase design, and in order to further improve the performance, a circular path for feed displacement is introduced to take the place of the conventional lateral path. Based on the introduced scheme, a Ku band bifocal single reflectarray antenna is designed for limited scan range application. The scan performances of the designed reflectarray are analyzed numerically and compared with conventional parabolic design. Numerical results show that the bifocal design shows significant improved scan performance with less 0.8 dB gain loss and lower than -13 dB side lobe level over entire scan range -30° to +30°, which illustrates that the bifocal design for limited field of view beam scanning reflectarray is a promising attempt.

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Yu Zhai ◽  
Ding Xu ◽  
Yan Zhang

This paper presents a lightweight, cost-efficient, wideband, and high-gain 3D printed parabolic reflector antenna in the Ka-band. A 10 λ reflector is printed with polylactic acid- (PLA-) based material that is a biodegradable type of plastic, preferred in 3D printing. The reflecting surface is made up of multiple stacked layers of copper tape, thick enough to function as a reflecting surface (which is found 4 mm). A conical horn is used for the incident field. A center-fed method has been used to converge the energy in the broadside direction. The proposed antenna results measured a gain of 27.8 dBi, a side lobe level (SLL) of −22 dB, and a maximum of 61.2% aperture efficiency (at 30 GHz). A near-field analysis in terms of amplitude and phase has also been presented which authenticates the accurate spherical to planar wavefront transformation in the scattered field.


Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2181
Author(s):  
Ziyang Wang ◽  
Xiaotian Pan ◽  
Fan Yang ◽  
Shenheng Xu ◽  
Maokun Li

A reconfigurable electromagnetic surface has been studied to realize the adjustable orbital angular momentum (OAM) beams for real-time wireless communication and dynamic target detection in the future. OAM mode switching realized by many previous designs suffers from low gains without OAM beam scanning. In this article, a 1-bit reconfigurable reflectarray antenna is designed, fabricated, and tested for the real-time control of OAM mode switching and large-angle vortex beam scanning in three-dimensional space. The proposed reflectarray surface is composed of 1-bit electronically reconfigurable cells, and the size is 24 λ × 24 λ with 2304 units. The reconfigurable element is designed by using a radiation patch loading a PIN diode with effective control of two states, “ON” and “OFF”, for the demand of 180° phase difference. The reflectarray surface can be assigned to a code sequence of 0 or 1 by the Field-Programmable Gate Array (FPGA) in real time. Henceforth, the coding surface can dynamically control the generation of high-gain OAM beams, where only the optimized phase distributions on the surface need to be changed according to demand. To verify the concept, a large-scale reflectarray surface is fabricated and measured with an oblique feed at 15°. Different OAM-carrying phase distributions for different OAM beam states are calculated and tested. The test results show that the OAM mode switching between l = 1 and l = 2 is realized, and other variable modes such as l = 3 or l = 5 can also be achieved by modifying the phase encoding sequence. Furthermore, the direction of the vortex beams can be accurately controlled with gains over 20 dBi, and the large-angle vortex beam scanning is verified. Therefore, all results demonstrate that the proposed 1-bit reconfigurable reflectarray is efficient for the regulation and control of OAM-carrying beams for the demand of real-time dynamic wireless communications in the future.


Author(s):  
Luong Xuan Truong ◽  
Truong Vu Bang Giang ◽  
Tran Minh Tuan

This paper proposes a new design of low sidelobe level (SLL) and high gain linear printed Vivaldi antenna array. The array composes of two parts, which are a linear Vivaldi antenna array and a back reflector. The array consists of 10 single Vivaldi antennas and a series-fed network, those are based on Roger RO4003C substrate (ε = 3.55) with the dimension of 140 x 450 x 1.524 mm3. A new Bat algorithm with the amplitude-only control technique has been applied to optimize the output coefficients of the series-fed network for gaining a low SLL. The simulation results indicate that the proposed antenna provides a low SLL of -29.2 dB in E-plane with a high gain of 16.5 dBi at the frequency of 3500 MHz. A prototype of the proposed antenna array has been fabricated. The measured data has a good agreement with the simulated data.


2012 ◽  
Vol 58 (1) ◽  
Author(s):  
M. F. Ismail ◽  
A. Wahid ◽  
M. K. A. Rahim ◽  
F. Zubir

A dual layer microstrip reflectarray composed of two stacked arrays with Minkowski and square patches of variable dimension is presented. The reflection phase coefficients on the reflector surface is achieved by tuning the dimensions of the patches. This technique is to broaden the bandwidth and to extend the reflection phase range compare to a conventional single layer reflectarray. From the simulation results of a unit cell composed of two stacked arrays of Minkowski and square patch showed that, 415° reflection phase range is achieved and lower insertion loss which is lower than 0.9 dB. Base on the simulated reflection phase coefficient, a dual layer microstrip reflectarray antenna with Minkowski and square radiating shape elements have been design and model using commercially available computer models of CST Microwave Studio. The reflectarray has been constructed using Taconic RF-35 substrate. From the radiation pattern at 11 GHz frequency, it shows that the HPBW of 4.7º in both plane, a side lobe level (SLL) of –17 dB and a maximum directivity of 26.1 dBi.


A single feed microstrip patch elliptically annular antenna array has been proposed for high gain circularly polarized (CP) radiation. An array of elliptically annular patches antenna resonates at a frequency of 3.77 GHz which can be used in satellite communication and radar application. A corporate feed network with quarter-wave transformer has been used for uniform excitation of all the array elements. Thus a good circular polarization is obtained by using a single feed with enhanced gain 15.62 dB compared to single patch. The radiation pattern, axial ratio and input impedance of the proposed elliptically annular antenna array is compared with single element elliptically annular antenna. A substantial gain enhancement with low side lobe level (SLL) is observed keeping circular polarization intact. Further, simulated and measured results of the proposed antenna array have been compared and found that axial ratio and gain are in good agreement.


2017 ◽  
Vol 6 (4) ◽  
pp. 63-69 ◽  
Author(s):  
R. Singha ◽  
D. Vakula

A broadband gradient refractive index (GRIN) metamaterial is used to improve the gain of the tapered slot antenna. The proposed metamaterial is capable of reducing the side lobe level of the antenna. The gradient refractive index (GRIN) metamaterial is constructed by using non-resonant parallel-line unit cells with different refractive index. Due to the non-resonant structure, the proposed unit cell exhibits low loss and large frequency bandwidth. The metamaterial, whose effective refractive index is lower than that of the substrate on which the antenna is printed. Therefore, the proposed metamaterial is act as a regular lens in beam focusing. The GRIN metamaterial is integrated in front of the antenna which has the capability to manipulate electromagnetic wave accurately. The measurement results indicate that the reflection coefficient of the antenna is below -10 dB over the frequency band from 3 to 11 GHz. The radiation pattern of the antenna shows the beam width becomes narrow and directive with low side lobe level. The peak gain is increased by 2.1 dB at 9.5 GHz.


2018 ◽  
Vol 60 (3) ◽  
pp. 709-713 ◽  
Author(s):  
Amin Darvazehban ◽  
Seiran Khaledian ◽  
Omid Manoochehri ◽  
Mohammad Ali Salari
Keyword(s):  

2018 ◽  
Vol 915 ◽  
pp. 231-236
Author(s):  
Harun Mecidoglu ◽  
Hamid Torpi

In this thesis, the RF front-end was done at K/Ka (18-27 GHz/26.5-40 GHz) bands used for satellite communication and satellite TV [1]. In this study, vertical polarized signal transmission and horizontal polarized signal reception were performed. The design is set to be compatible with TURKSAT 4B [2]. RF front-end is consist of an offset dish providing high gain and low side lobe level (SLL) for collecting the signal, a circular horn antenna which is compatible with RHCP (Right Hand Circular Polarization) and LHCP (Left Hand Circular Polarization) polarizations at the focal point of the dish, to separate dual polarization an orthomode transducer (OMT) and a transmit reject filter to prevent the receiver from the strong signal generated at the transmitter side (cross-pol). In the design waveguide structures is used to work in microwave frequencies and for high power delivery requirements. AWR Microwave Office, Computer Simulation Technology (CST) and MATLAB (Matrix Laboratory) programs are used for simulation, optimization and calculations.


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