Introduction to DGS: The Concept and Evolution

This chapter addresses some insightful fundamentals which cover the evolution starting from the concept of photonic crystals, the working principles, known geometries along with an account of their chronological developments, and different areas of applications. Defected Ground Structure (DGS) means a single or a limited number of slots strategically etched on the ground plane of a microwave printed circuit board to attribute a feature of stopping wave propagation over a band of frequencies. The DGSs can be broadly classified into two categories depending on their configurations: single unit cell DGS; and multiple unit cells with uniform or non‐uniform periodic arrangement. The feature of tunability of resonance has been examined with the DGS geometries. Since its inception in 2000, the DGS has been applied to almost all major printed circuits and antennas to enhance their performance and mitigate some design issues.