3D printed wideband flat gain multilayer nonuniform reflectarray antenna for X‐band applications

Abstract

Reflectarray antenna designs have become an efficient solution alternative to their counterpart designs due to their beam scanning capability, low profile, high gain, and mounting flexibility. Herein, design and realization of a wideband, flat gain multi-layer nonuniform reflectarray (MNURA) using 3D printing technology is presented. Design optimization of the proposed MNURA has been achieved in the two stages: First, a 3D CST Microwave Studio based Multilayer Perceptron Neural Network (MLP NN) model establishes the reflection phase characteristic of the MNURA unit element as an accurate continuous function of the geometrical design parameters and dielectric constant. Then Differential Evolutionary Algorithm DEA is selected as a powerful optimization algorithm for determining the optimum geometrical design parameters and dielectric constant of MNURA throughout the X-band to have a large range, wideband, and flat gain RA design. 3D printing technology has been used for prototyping of the proposed MNURA design. Here, the resulted optimum dielectric constant value of 2.2 is realized by 56% infill rate of "Polar White" PLA using the relation between the infill rate and dielectric constant. The prototyped antenna has a total size of 300 × 300 (mm), and its measured performance characteristics achieve a wideband flat gain of 23.2 dBi with a ripple level of almost 1.5 dBi and return loss characteristic of less than −10 dB over the operation band of 8 to 12 GHz. K E Y W O R D S 3D printer, flat gain, multilayer perceptron neural network, reflectarray, wideband, X-band 1 | INTRODUCTION Due to their beam scanning capability and being low profile, reflectarrays (RAs) have become an efficient solution alternative to their counterpart design of reflector and phased array antennas. RA designs are simply hybrid of a reflector antenna and a planar phased array antenna which has a suitable phasing scheme in order to convert the incoming spherical wave produced by a feed antenna into a pencil beam in a specified direction. 1-4 With respect to their unique features of high gain, mounting flexibility, and being planar, Microstrip Reflectarray (MRA) designs have a wide range of applications such as space, radar, and long-distance communication applications. 5 However, these designs suffer from disadvantage of having a narrow bandwidth characteristic. Thus, the narrow bandwidth characteristics caused by intrinsic narrow bandwidth of a microstrip patches and spatial phase delays between the feed and unit cell elements 6 is a challenging design problem.

Ensemble‐based surrogate modeling of microwave antennas using XGBoost algorithm

“…65 The challenging problem in reflectarray designs is their need of high computational power for optimization process, which requires a high-performance hardware setup or long simulation duration. 66,67 One of the efficient solutions for having fast design optimization of reflectarray designs is the usage of data-driven surrogate models that create a mapping between geometrical design parameters of unit elements and the reflected EM wave phase. 63 In Ref.…”

3D EM data‐driven artificial network‐based design optimization of circular reflectarray antenna with semi‐elliptic rings for X‐band applications

“…This data is obtained as the phases of the reflected waves from the unit cell placed at the termination plane of the TEM mode waveguide simulator implemented the 3D CST MWS‐based analysis (Figure 1B). 3,4 The optimum MLP NN structure is generated by applying Backpropagation Bayesian regularization, which is resulted with the three hidden layers having 15, 30, and 15 neurons respectively, with Mean Absolute Error value of 0.5°. Thus this MLP NN provides an accurate and fast model for the continuous function of the reflection phase φ R for a unit semi‐elliptic ring RA element in terms of the geometrical variables and frequency for the selected ring width w = 2.5 mm.…”

Wideband 3D‐printed dielectric reflectarray in Ka‐band

“…The dielectric reflectarray based on 3D-printed has a wider bandwidth, low cost and simple production. [13][14][15][16][17][18] The multi-layer non-uniform reflectarray 13 and the circular-hole dielectric reflectarray [14][15][16][17][18] using PLA printing technology have improved a certain operating bandwidth.…”