Study And Implementation Of Antenna Optimization Based On Parallel Calling Fit Software

In the antenna design process always involves the problem about optimization, which use traditional methods often have certain degree of difficulty and challenge. If the problem is complicated, in the course of the antenna modeling and solving because of the serial nature of the program, the optimized efficiency is often low. To solve the above problem, an automatic optimization approach of microwave passive components design based on differential evolution strategy (DE) and MPI parallel framework, though externally parallel calling the solver of electromagnetic simulation FIT software as the tool for calculating the antenna, is developed in this paper. In order to demonstrate the effectiveness and the feasibility of this application, several antennas are designed and optimized.Firstly, the electromagnetic simulation FIT software and differential evolution strategy are introduced. The simulation FIT software has the powerful function of setting up solid models and plotting out computation mesh automatically. The theory base of the optimization program is differential evolution strategy. Then the code of differential evolution strategy is written by analyzing its principle and characteristic. The code's correctness is validated with several canonical test functions.Secondly, Visual Basic interface program is developed in order to combine external differential evolution module and FIT software with seamless integration, which's own Visual Basic for Applications macro language provides the possibility for this combination. The serial program with differential evolution strategy through externally calling FIT software to optimize antenna is implemented. Using this program, an ultra-wideband notch patch antenna was designed with optimizing the location and length of the slot. The simulated results show that the designed antenna is applicable in UWB system, with the trap frequency range is from 5.62GHz to 6.01 GHz. Satisfy the design requirements of the antenna. The approach establishes a foundation for application in parallel computation technology to improve the efficiency of optimization.Thirdly, the involved parallel differential evolution focusing on realized model was mentioned. With the introduction of the coarse-grained parallel model and Transport Operator in the serial program, achieve the program of parallel calling FIT software to optimize antenna. The detail steps and features of this approach are mainly discussed here. The same patch antenna with an ultra-wideband is both optimized by the serial and parallel methods. Through comparing the optimization time and the final results, demonstrate the effectiveness and efficiency of this parallel differential evolution optimization program.Finally, with the parallel optimization program, two kinds of ultra-wideband antenna array are optimized and designed. One is the knife-type horn antenna array, as both in the E-plane and H-plane composing arrays, effectively reducing the beam width of the enhanced direction. By increasing the wire and optimizing the distance between antenna elements and other parameters, satisfying the front and behind radiation and direction design requirements. The other is non-uniform arrangement of Vivaldi antenna array, with the mirrored elements are placed alternately in the H-plane to cancel out the cross-polarized fields. Though optimizing the array element spacing, the high main lobe gain is achieved, while the maximal side-lobe level of the array is limited.