Design of UHF log-periodic dipole antenna
Date of Issue2016-06-01
School of Electrical and Electronic Engineering
Ultra High Frequency (UHF) has been widely used in the wireless communication of aircrafts, especially the Unmanned Aerial Vehicle (UAV). Because of the specific requirements for the aircraft, such us the wide bandwidth and small size, it is significant and practical to do the research on the UHF miniaturized antenna. This thesis mainly researches on the significance of the aircraft antenna and its research status, and then introduces the basic theory and mathematic method of the log-periodic antenna techniques, additionally with the common methods of miniaturization technology, which have been proposed by many experts. All these works provide the academic foundation for the antenna design. This thesis studies the UHF log-periodic dipole antenna (LPDA). It starts with the main parameters of the log-periodic dipole antenna and then provides a basic antenna design. Furthermore, a modified structure is proposed with the basic design, in which a resister is connected to the open-end of the antenna and also a load hat is added at each end of the element to reduce the antenna size, meanwhile broadening bandwidth. After the analysis of the theory and design, this UHF loaded antenna is simulated on HFSS. Through the parametric study, the parameters get optimized and the final structure is determined. Finally, the antenna is fabricated and tested by some related equipment, with the measurement results in good agreement with the simulated results. The miniaturized UHF log-periodic dipole antenna designed in this thesis not only has good VSWR, radiation patterns and high realized gain, but also has small physical size, which satisfies the specific UAV requirements.
DRNTU::Engineering::Electrical and electronic engineering