Sun Baohua

Efficient optimization of flat-top patterns using genetic algorithm for the deep space detection application

The optimization of a flat-top pattern of planar 2-D array antenna is proposed in this paper. The shaped-beam planar array is employed to be an element of very large array for the deep space detection. A conventional genetic algorithm is chosen for the optimization. However, the synthesis of a flat-top shaped beam using a planar 2-D array is difficult because of the inherently large number of degrees of freedom involved in the algorithm (in generally, the amplitude and phase of each element must be determined). Therefore, a sub-array rotation method, which lies on the flat-top pattern synthesis itself, is proposed in this study to resolve the design problem. A 10times10 (100) element array is employed, and the results of the optimized flat-top pattern are shown to illustrate the validity and high efficiency of the technique.

Rigorous full-wave analysis of the base-station antennas

Rigorous analysis of the Base-Station (BS) antennas with reflector is made in this letter. The wire-grid modeling of BS antenna is established. In order to improve the solution accuracy and efficiency, some efficient techniques such as three-term sinusoidal interpolation basis function and discrete wavelet transform are used. Numerical examples considered here are the typical vertically polarized and the dual-polarized BS antennas. The calculated results for the vertically polarized BS antenna are in good agreement with the measured data, which show that the analysis modeling used is accurate and reliable.

ANALYSIS OF MONOPOLE ANTENNA ON CIRCULAR DISC BY MODE MATCHING

Mode matching is used for the analysis of monopole antenna on circular disc, which is achieved by developing a novel model consisting of two artificial ground planes above and bellow the monopole antenna. Using this model, the input impedance is computed and compared with measured data reported in literatures, and excellent agreement is observed.

A NEW MOMENT METHOD FOR THE FAST AND ACCURATE ANALYSIS OF NORMAL MODE HELICAL ANTENNAS

In this letter, a new moment method using helical segments is presented to model Normal Mode Helical Antenna (NMHA). Using this method, the NMHA can be modeled by a few segments. The current distributions and radiation patterns of some NMHAs are calculated. A comparison is made between results obtained using this helical segment algorithm and a linear segment algorithm, and the results of the two algorithms agree fairly well. When calculating the impedance matrix [Z], all the elements of the matrix can be obtained by only calculating a few elements with the application of the symmetric and periodic characteristics of the NMHA. Therefore, the CPU time and the memory storage are significantly reduced, with the accuracy and speed enhanced.