Optimizing the Gain of an Array in a Particular Direction to Enhance the Detection of Arrival Signal

Direction-Of-Arrival (DOA) detection is a fundamental procedure required by several monitoring and tracking systems for defense purposes and other security applications as well as industrial monitoring and measurement. The ability of a system to accurately determine the incident angle of an arbitrary electromagnetic wave incoming toward the observer device is an important as well as challenging task especially when low-cost and robustness are also key points for the overall tracking and detection or surveillance solution. So several Direction of Arrival DOA estimation algorithms were developed relying on basic array configurations, in most algorithm the effects of mutual coupling between antenna elements is not considered. When antenna elements are placed in an array structure, where the antenna elements are situated in the near-field region of the other antennas, the radiation characteristics of the antennas differ from the stand-alone radiation characteristics. Compensating for these mutual coupling effects in DOA estimation algorithms in a real challenge. This paper discusses an algorithm for optimizing the gain of an antenna array on an incoming signal. An algorithm for optimizing the gain of an adaptive antenna system is discussed. The gain optimization is accomplished by a constrained gradient-search technique. The algorithm is presented and some simple examples showing how the gain is optimized in a four-element array are given. The formalism descring the optimizing the gain of an array in a particular direction has been applied to the rectangular array, by assume that Θ = 30⁰, φ =45⁰, and optimizing in this direction. The results concerning the variation of the maximum gain with the number of five to seven elements.