摘要 : Today, microstrip antennas have received a lot of attention due to their unique features such as low weight and volume, easy and cheap construction, and the ability to adapt to planar structures. Of course, the important problem w... 展开 Today, microstrip antennas have received a lot of attention due to their unique features such as low weight and volume, easy and cheap construction, and the ability to adapt to planar structures. Of course, the important problem with these antennas is their small gain and bandwidth. In this paper, the gain and bandwidth of the microstrip antenna with a patch in the form of Antipodal Vivaldi are improved by using log-periodic structures. Three 8-element log-periodic structures designed in a straight-line, U-shaped and V-shaped are proposed, simulated and fabricated. The dimensions of these antennas are 287.2 × 48 mm 2 , 182.5 × 160 mm 2 and 195 × 200 mm 2 respectively. The results of the measurements show that the bandwidth of the 8-element straight-line, U-shaped and V-shaped antennas are 3–18, 2.6–18, and 2.4–18 GHz respectively, and their maximum gain are 6.26, 8.3, and 7.61 dBi, respectively, which has increased the bandwidth by approximately 125% compared to the single element mode and increased the gain from 2.26 to 4.3 dBi. These quantities show that among the three antennas proposed in this article, the V-shaped antenna has the highest bandwidth (15.6 GHz) and the U-shaped antenna has the highest maximum gain (8.3 dBi). Of course, it is possible to achieve more gain by changing the angle between the branches of the V-shaped antenna, but it may ruin the bandwidth. 收起