Design and optimization for the satellite Ku-band CP array antennas

The goal is to design a Ku-band circular polarization array for satellite application, and an array of circular polarization satellite antenna covering 11.45~12.75GHz is reported. The Wilkinson equal-power splitter is first used to feed the signal power into the array, for which we have examined the simulated characteristics of the 2×1 and 2×2 arrays, while the prototype of the 2×2 array is fabricated and measured for verification purpose. Then the phased array antenna is optimized by genetic algorithms to determine the optimum parameters for the phase shifter. Note that the coupling effect between the antennas elements must be took into account to achieve good accuracy. To accomplish this, we have to calculate in advance the radiated E fields of the entire antenna array (at least including the neighboring components) with only a single antenna element being excited. The far zone E fields Er of all the angles (up to one degree resolution) are obtained and saved for successive optimization using GA algorithm. The optimum result could be programmed into a microprocessor to control the array antenna steering electronically.