A Parasitic Hat for Microstrip Antenna Design Based on Defected Structures for Multiband Applications.

In this article, a novel design of a quadband parasitic hat microstrip antenna is proposed for multiband applications. The proposed antenna consists of a rectangular patch of dimensions 30 mmχ11 mm cut with four L-shaped slots connected with a rectangular slot in the middle of the front side of the antenna to form a parasitic hat based upon defected microstrip structure. On the other side of the antenna, a defected ground structure is integrated as five rectangular slots embedded in the ground plane with the same width but with various lengths. The suggested antenna is designed and fabricated on a substrate material with an area of 45 χ 40 mm2 with a thickness of 1.52 mm to generate four frequency bands. The proposed antenna is fed by a microstrip transmission line. The simulated radiation patterns, return losses, maximum gains, and efficiencies of the antenna are carried out by using electromagnetic simulation software based on the finite element method. The measured return loss results validate that the suggested antenna can be designed to cover the frequency ranges from (3.8464 to 4.1456) GHz for sub-7GHz 5G applications, (6.7 to 7.162) GHz for ultra-wideband applications, (9.1616 to 9.5187) GHz for maritime radio-navigation positioning systems, and (11.5421 to 16.4085) GHz for radionavigation satellite standards. The suggested antenna is based upon defected ground structure and defected microstrip structure techniques to improve the antenna performance. [ABSTRACT FROM AUTHOR]