Design of Compact Dual Band Microstrip Antenna using DGS and Shorting Post Methods

In this paper a low profile, compact dual band microstrip antenna has been presented. The proposed design for the size reduction consists of hybrid techniques that is both Shorting Post and Defected Ground Structure (DGS). DGS is produced by trimming circular slots on the ground and Shorting posts are drilled as Plated through Holes (PTH) through the substrate from patch to ground for more reduction of the size. Implementing these results in increase of antenna electrical length which accompanied with raise in the path of current distribution. The final designed antenna is compared with conventional patch antenna which is designed without size reduction methods. The resulting final antenna is smaller than the conventional patch antenna by 42.25%. The designed antenna is fabricated and it's characteristics are tested using Vector Network Analyser and proposed design resonates at both 900 MHz and 1800 MHz frequencies which we use for Global System for Mobile(GSM) applications. This antenna is used in many wireless communication systems like Laptop, Cell Phone, Radio Detection and Ranging (RADAR) where compactness is required.