Circular Aperture Plane Antenna Array Design Optimization Algorithms

Sparse antenna array is the array whose elements are non-uniformly distributed in the array aperture. Under the condition of the same number of elements, the aperture of sparse antenna array is larger than uniform antenna array with the same geometric structure. So sparse antenna array has more narrow scanning beam and better spatial resolution. Sparse antenna array is very suitable for the applications that need a narrow main beamwidth while a high gain is not required. In addition the element spacing is larger,so the mutual coupling between elements of sparse antenna array is reduced. With these advantages, sparse antenna array has considerable practical value.The peak side-lobe level(PSLL) is an important index for the performance evaluation of antenna array. It is an important aspect of the study on the synthesis of sparse antenna array to reduce the PSLL. However, the optimization of PSLL is a complex nonlinear optimization problem in mathematics. In recent years, with the rapid development of computer technology, Intelligent Algorithm such as Genetic Algorithm(GA) has been widely used in the area of synthesis of sparse antenna array and promote it to the direction of large scale and multiple constraints.In this paper, A real GA and a binary GA are used in the study on the side-lobe level optimization of circular plane antenna array with multiple constraints and a large scale. The main contents are as follows:1. A new method based on MGA is put forward for the synthesis of sparse circular plane array with the design constraints of the element number, aperture and minimum element spacing.The constraints can still be meet by setting rational parameter of the Archimedes Spiral when elements are located along it. So the synthesis of sparse plane array is converted into element position synthesis of sparse linear array. This method effectively reduces the complexity of this problem. Generalized crossover operator and mutation operator are applied in order to make sure new individuals still meet the constraints after genetic operation.2. A binary GA is used in the study on the optimization design of thinned concentric ring antenna array and find a method to improve the efficiency of the optimization design of thinned concentric ring antenna array.3. A real coding MGA is used in the optimization of ring radius when the adjacent ring spacing is between0.5λ and A to get the its side-lobe performance.4. A real coding GA is used in the optimization of the uniform concentric ring antenna array to get its side-lobe performance by changing the number of elements on each ring.5. In the foundation of uniform concentric ring antenna array model, a study on the synthesis of sparse circular plane antenna array with low side-lobe is carried on with the constraints of aperture and minimum element spacing. The individuals meet the constraints by constructing template vector. It increases the freedom in selecting elements position by taking the residual phase of each ring into consideration.