A Reflectarray with Octagonal Unit Cells for 5-G Applications (original) (raw)
Related papers
Iranian Journal of Science and Technology, Transactions of Electrical Engineering, 2019
This paper presents two designs of reflectarrays with two different unit cells: a novel broadband microstrip unit cell and a 3D all-metal unit cell. The microstrip unit cell consists of two concentric octagonal rings plus an octagonal patch with an empty cross inside. On the other hand, the all-metal unit cell is composed of a pure copper cuboid. These reflectarrays are designed to work around 28 GHz for suitable 5G operation. A pyramidal horn antenna is used for the feeding purpose. The F/D ratio is equal to one. The reflectarray is 107 mm × 107 mm in dimensions. The simulation results show that the reflectarray based on the microstrip unit cell achieves a 1-dB gain-bandwidth of about 31.2% with a gain equal to 27.2 dB at 28 GHz. On the other hand, the all-metal reflectarray achieves a 1-dB gain-bandwidth of 14.5% and a gain equal to 28.5 dB at 28 GHz. From the obtained results, it is clear that the microstrip reflectarray is superior from the gain-bandwidth perspective, while the allmetal reflectarray is superior from the gain perspective. The microstrip reflectarray has been fabricated, and its performance has been measured. A good agreement between the simulation and measurement results has been achieved.
Design and Analysis of Reflectarray Compound Unit Cell for 5G Communication
Applied Computational Electromagnetics Society, 2020
In this paper, a single-layer compound unit element is proposed for reflectarray antenna design operating in Ka-band (26.5-29.5GHz) at the center frequency of 28GHz. A systematic study on the performance of a compound unit element is examined first. The structure of the proposed unit element is a unique combination of two different shape simple patches i.e. cross dipole and square patches. The desired phase range is achieved due to the multi-resonance of both patch elements with a single layer without any air-gap. The compound unit element is simulated by computer models of CST Microwave studio based on the Floquet approach (infinite periodic approach) and it has achieved 348.589o reflection phase range. Furthermore, the analysis of the reflection phase range, S-curve gradient, reflection magnitude, fabrication tolerance, and surface current density is also simulated and demonstrated. Based on the remarkable performance, the proposed element can be considered as the best element of ...
Comparison and Analysis of Unit-Cell Environment Behavior of Reflectarray Antenna
2016
The reflectarray combines much of the simplicity of the reflector antenna with the performance of the array antenna. This paper presents an analysis and design of unit cell of reflectarray antenna using a square patch and square loop radiating elements and the steps taken in the design of a reflectarray unit cell operates in X -Band (8-12 GHz) at the center frequency of 10 GHz. The result of an analysis is generated from the Computer CST Microwave Studio using the approach of Floquet. This model takes into account a mutual coupling between elements, and is an efficient way to accurately characterize reflectarray elements.
Design and Simulation of a Reflectarray Antenna using New Cell for Different Beam Angles
International Journal of Grid and Distributed Computing, 2016
In this paper a new cell is proposed for reflectarray antenna and is used to design the antenna to obtain to maximum gain and efficiency using phase synthesis in a frequency band of 11 GHz up to 11.7 GHz for different beam angles. The proposed cell is a double ring of hexagon which introduces multiple resonances which can provide more than 360 degrees phase variation by changing the loop size. Design method is based on phase-only algorithm where amplitude of the field on the reflectarray surface is forced by the feed. A 1.2 m reflectarray is designed for different beam directions. The results show maximum directivity of 42 dB and maximum efficiency of 73% for the required bandwidth. Focal length is 1.5 m which is set for maximum efficiency.
Design and Analysis of 28 GHz Millimeter Wave Antenna Array for 5 G Communication Systems
2018
Microstrip patch antennas with significant attributes such as low cost, light weight, low profile and compatible with Monolithic Microwave Integrated Circuit are used widely in mobile communication. This paper presents the design of 28 GHz microstrip patch array antenna. The patch is designed using the substrate Rogers RT Duroid 5880 with a dielectric constant ɛr = 2.2 and a thickness of 0.254 mm. The overall dimension of single patch is 14.71 mm x 7.9 mm x 0.254 mm. A quarter-wave transformer is incorporated and a lumped port is used to excite the antenna having an input characteristic impedance of 50 Ω. And further the design performance of a 2 x 1 and 4 x 1 array is evaluated on Roger Duroid 5880 without and with reflective materials for gain enhancement. The gain of the 2 x 1 array is of 10.20 dB and the 4 x 1 is 13.55 dB. Furthermore, the proposed design performance is evaluated on different types of substrate and with varied substrate thickness. The comparative analysis clearl...
Microstrip Reflectarray Design for 26 GHz
The European Journal of Research and Development
This paper presents microstrip reflectarray design using variable size unit cell approach for 26 GHz, and investigates the effect of feed antenna distance to the surface. The unit cell structure is made up of a 1.5 mm foam layer (εr=1.37) and a 0.787 mm substrate layer (εr=2.2) between the ground and reflective layers. Two arrays of 14λx14λ in size were designed to reflect the incoming wave in the θ=25º direction; the distance to the feed was 160 mm in one design and 320 mm in the other design. Simulation results show gain of 30.2 dBi for the former and 29.8 dBi for the latter. 3-dB gain bandwidths were 11 % and 14 %, respectively
Dielectric Resonator Reflectarray Antenna Unit Cells for 5G Applications
International Journal of Electrical and Computer Engineering (IJECE), 2018
This paper presents an investigation for the performance comparison of three different unit cell configurations operating at 26 GHz for 5G applications. The unit cells are cross shape dielectric resonator, cross microstrip patch and cross hybrid dielectric resonator. Verification of the comparison has been done by simulations using commercial Computer Simulation Technology Microwave Studio (CST MWS). The simulated results for reflection phase, slope variation, reflection loss and 10% bandwidth were analyzed and compared. The results indicate that the optimum configuration to be deployed for the reflectarray's unit element in order to fulfill the 5G requirements of a wide bandwidth is the cross hybrid DRA. This configuration is a combination of cross DRA with cross microstrip patch as the parasitic element in order to tune the phase and provide a wide phase range with smooth variation slope. Cross hybrid DRA provided a wide phase range of 520° with 0.77 dB loss and 10% bandwidth of 160 MHz.
Reflect-Array Design for 28 GHz
This paper presents results of a high-gain fixed-beam microstrip reflect-array design for 28 GHz using variable size unit cells. The array employs a simple, single-layer structure on a 0.508 mm Roggers 5880 substrate. It comprises 33×33 unit elements over 198×198 mm surface. Each unit cell is 6x6 mm size, i.e. ×. at 28 GHz, and has a square patch at the center, size of which is varied between 2 mm to 4.5 mm in order to derive a highly directive beam in a desired direction. Simulation results show a highly directive beam, with low side-lobe level for reflection angles in the (-50, 50) range. The array has a gain of 32.5 dBi at 20° beam direction, half-power-beam-width of 3.15°, and a sidelobe level of-17 dB. For the 50° beam direction, the corresponding values are 30 dBi, 5.1° and-15.6 dB, respectively.
On Radiation Performances of Reflectarray Antennas Constructed With Subwavelength Unit Cells
IEEE Antennas and Wireless Propagation Letters, 2015
Multi-element approach is utilized to increase the phase variation range of a square-ring sub-wavelength unit cell (UC) from 313° to more than 560°. Radiation characteristics of three thin reflectarray antennas (TRAs) constructed with the proposed UCs are investigated. This investigation demonstrates that to achieve a broadband highly efficient TRA, the employed λ/5-UC must have reflection loss considerably less than 0.1 dB and its constructing elements should also scatter the incident fields in the same fashion, i. e., the current distributions of all parts of the multi-element UC are of the same shape and cophased.
Design and SAR assessment of three compact 5G antenna arrays
Scientific Reports
In this paper three different multi stub antenna arrays at 27–29.5 GHz are designed. The proposed antenna arrays consist of eight single elements. The structure of feeding parts is the same but the radiation elements are different. The feeding network for array is an eight way Wilkinson power divider (WPD). To guarantee the simulation results, one of the proposed structures is fabricated and measured (namely the characteristics of S11, E-, and H-plane patterns) which shows acceptable consistency with measurement results. The simulation results by CST and HFSS show reasonable agreement for reflection coefficient and radiation patterns in the E- and H- planes. The overall size of the proposed antenna in maximum case is 29.5 mm × 52 mm × 0.38 mm (2.8 {{\varvec{\lambda}}}_{0}$$ λ 0 × 4.86$${{\varvec{\lambda}}}_{0}$$ λ 0 × 0.036$${{\varvec{\lambda}}}_{0}$$ λ 0 ). Moreover, for Specific Absorption Rate (SAR) estimation, a three-layer spherical human head model (skin, skull, and the br...