1. Field of the Invention
The present invention relates to an apparatus for recognizing a security code having an electromagnetic band gap (EBG) pattern.
2. Description of the Related Art
Generally, Microwave Band Gap (MBG) structures or EBG structures are implemented on microstrips, and are used for various purposes, e.g., improving the performance of an antenna, improving the power efficiency of an amplifier, realizing the high quality (Q) of a resonator, controlling harmonic components, and designing a new type of duplexer. Microstrip circuits applied to such EBG structures can be manufactured using a method of punching a dielectric substrate, a method of etching a ground surface to have a uniform shape, and a method of changing a microstrip line itself.