In this thesis, I demonstrate a genetic-algorithm-based optimization method for designing matching and decoupling networks (MDNs) for asymmetric two-element antenna arrays. The proposed method considers practical aspects in MDN realization by accounting for short pieces of transmission lines between the lumped elements and only using capacitor/inductor values from a predefined database of commercially available lumped component values. In addition, the proposed algorithm is able to explore all subsets of a general MDN topology in its search for a solution, providing some flexibility for system optimization (e.g., reducing the number of lumped elements used in an MDN). Details about the proposed approach along with performance analysis of four design examples based on this method are presented. One of the designs was fabricated and measured to demonstrate the effectiveness of the proposed design method. Chapter 1 provides the motivation and context for this work with relevant literature review and objectives of this thesis. Chapter 2 reviews existing MDN design techniques and discusses practical design considerations for the proposed method. Chapter 3 briefly discusses the basics of genetic algorithm (GA) and its relevance to this work. Chapter 4 presents the method proposed in my thesis work and describes how the genetic algorithm is implemented for designing MDNs for asymmetric two-element antenna arrays. Chapter 5 reports the details of four different MDN design examples along with their simulation and measurement results. Chapter 6 concludes the thesis work and discusses potential future development to further advance this work.