Design and manufacture of the broadband Spiral antenna with the elimination of left circular polarization and tapering microstrip balloon of 50 ohms.

Today, antenna with high bandwidth is very important in commercial and military sectors. Helical antennas are of independent frequency type that can solve this demand. In this article, we have reached this demand by using a two-span Archimedean spiral antenna with the width of each arm equal to 0.24 mm. This structure is simulated and built using HFSS software. One of the advantages of this antenna is the 12 GHz bandwidth, which includes the frequency band from4.5 to 16.5 GHz. By using the metal cover (cavity) the left-handed circular field produced by the helical antenna has been removed. Placing the absorber behind the antenna removes the electric and magnetic fields that disrupt the performance of the microstrip balloon. From the microstrip balloon structure, we were able to increase the impedance of the 188-ohm spiral antenna to 50 ohms. In the end, the manufactured antenna is tested and measured, and the measurement results are in good agreement with the simulation.