Ring Shaped Compact Microstrip Reflectarray Antenna

Regularly shaped compact microstrip antennas have a small size but their gain is insufficient for most applications. Therefore, a ring-shaped compact microstrip reflectarray with microstrip antenna feed has been proposed. Different configurations, namely, 1 × 3, 3 × 1, plus-shaped and 3 × 3 have been analyzed. The 3 × 3 configuration yields an optimum gain of 10.8 dBi and a narrow beamwidth of 22.7°.