Investigation on Octagonal Microstrip Antenna for RADAR & Space-Craft applications

In this paper octagon shape planar microstrip antenna is presented. Octagonal antenna can find applications in Radar and Space-crafts. The antenna is fed by a 50 Ω microstrip line and printed on a dielectric Fr4 substrate of dimension (22mm X 22 mm) permittivity εr =4.4 and height h = 1.6 mm. The optimization on the planar octagonal microstrip has been done to accomplish an -10 dB return loss bandwidth. Moreover, in comparison with a simple rectangular shaped antenna, the proposed design enhances the bandwidth and improves input return loss. Better than 83.54 % radiation efficiency has been achieved in the range 3.1 to 15 GHz. The parameters like substrate dimension, feed size and ground plane which affect the performance of the antenna in terms of its frequency domain and time domain characteristics are investigated.