Reseach On Grating Lobe Supression Methods Of Large Spacing Phased Array Antenna

In this paper, grating lobe suppression methods on large spacing phased array antenna in X-band were analyzed. Firstly the planar phased array antenna grating lobe’s formation and its avoiding were introduced. Then the paper put emphasis on the large spacing grating lobe suppression technology of phased array antenna.The grating lobe of large spacing phased array antenna could be reduced by certain methods. 1) Optimized the aperiodic element arrangement or aperiodic subarrays arrangement to distribute grating lobes energy. 2) Using high-powered element pattern, combining with the principle of pattern multiplying, it is an effective way to reduce array grating lobes for limited scan phased array. 3) Combining irregular element arrangement with the active pattern for element closely, grating lobe suppression effect is more significant. By these means, we designed some typical array arrangement which the grating lobe suppression effect is obvious, and analyzed the characteristics on far field radiation. The main contents include:1. Arrangement forms for the aperiodic large spacing planar octagonal array were researched in order to analyze its ability to suppress grating lobes, and low sidelobe technique, such as Taylor incentive distributions, was adopted. On the basis of researching radiation characteristics of periodic array and uniform array, avoiding the grating lobes as the main purpose, the forms of aperiodic octagonal array were designed.● Using stochastic optimization algorithms, optimized a kind of aperiodic octagonal array that consisted of a single sub-array;● Adopting DFP-BGFS variable metric optimization algorithm to optimize the central location for equal spaced sub-arrays, and finding a group of corresponding eccentric distribution.● Combined sparse array principles with characteristics of no parasitic gate lobes for uniform array,it was designed that the compact octagonal array composed of the multi-subarrays, and was used efficient feed element to suppress the grating lobe of far-field pattern.● Researched subarrays rotation octagonal array, arrangement form of planar array antenna was designed to analyze its grating lobe suppression.2. The grating lobe suppression was discussed for aperiodic ring gate array of equal spacing in the radial. Using heuristics to build two array structures: arc-ring gate array consist of fan-shaped sub-array and trapezoidal ring gate array consisted of trapezoidal subarray. Gave the arrangement forms of two structures, it was analyzed that radiation characteristics. The study found grating lobe level is low, and it is far beyond 50 ° from the normal position of antenna array.3. The grating lobe suppression was discussed for large spacing aperiodic planar rectangular array in terms of optimizing the eccentric distribution of equal spacing sub-array, designing an aperiodic rectangular to suppress grating lobes to analyze the impact of the sub-array size on grating lobes. The larger sub-array’s size is, the more obvious suppression of parasitic grating lobe.