Direct Optimization of Printed Reflectarrays for Contoured Beam Satellite Antenna Applications

Abstract

Abstract-An accurate and efficient direct optimization technique for the design of contoured beam reflectarrays is presented. It is based on the spectral domain method of moments assuming local periodicity and minimax optimization. Contrary to the conventional phase-only optimization techniques, the geometrical parameters of the array elements are directly optimized to fulfill the contoured beam requirements, thus maintaining a direct relation between optimization goals and optimization variables, and hence resulting in more optimal designs. Both co-and cross-polar radiation patterns of the reflectarray can be optimized for multiple frequencies, polarizations, and feed illuminations. Several contoured beam reflectarrays, that radiate a high-gain beam on a European coverage, have been designed and compared to similar designs obtained using the phase-only optimization technique. The comparisons show that the designs obtained using the proposed direct optimization technique are superior in performance, both for multi-frequency and dual-polarization designs. A reflectarray breadboard has been manufactured and measured at the DTU-ESA Spherical Near-Field Antenna Test Facility to validate the proposed technique. An excellent agreement of the simulated and measured patterns is obtained.

Design of aperiodic frequency selective surfaces for compact quasi-optical networks

“…For the optimisation of the aperiodic FSS, the direct optimisation technique from [7] is used. The optimisation engine uses a gradient-based non-linear minimax optimisation algorithm which is the same algorithm used in TICRA's software POS [8].…”

“…In the direct optimisation technique in [7], all individual array elements are optimised simultaneously. This can be challenging if the FSS consists of several hundreds of thousands of elements.…”

Introducing Deeper Nulls and Reduction of Side-Lobe Level in Linear and Non-Uniform Planar Antenna Arrays Using Gravitational Search Algorithm

“…Hence, designing array antennas with a desired radiation pattern has been extensively studied over the last few decades [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. In these problems, we need to control parameters which depend on the structure of an antenna, and they are required in order to achieve the desired radiation characteristics.…”

“…Some of the most important traditional analytical/deterministic methods are used for array antennas, such as WoodwardLawsen method, Chebyshev method, Schelkunoff method and Levenberg-Marquardt algorithm [14], steepest decent [15], gradient-minimax [16], and intersection approach [17,18], each of which is used to fulfill various purposes in designing array antennas patterns. Many drawbacks are associated with using deterministic methods such as shortcomings in designing array antennas with complex geometrical structures, consuming more computationally time as the number of the elements in the array increases, and some of these methods are from testing and trying type, having a large gap with the most efficient conditions.…”

Reflectarray antenna with reduced crosspolar radiation pattern

“…Then, the element of the reflectarray was appropriately modified using geometrical transformations to match the required coefficients. In [5] a direct optimization technique was developed based on a gradient minimax and the use of a database in order to avoid the direct use of MoM during the optimization process. Another approach is provided in [6] where an efficient generalization of the Intersection Approach algorithm is employed to synthesize the complex reflection coefficients which provide the desired radiation patterns with both copolar and crosspolar specifications.…”