Investigation and Optimization of Planar and Printed Antennas

Author: Tamar Makharashvili
Keywords: Microstrip patch antenna, rectangular patch antenna, wideband and U-slot antennas, log-periodic printed dipole array antenna, frequency notch.
Annotation:

Antenna is one of the most important means in radio frequency (RF) systems for receiving or transmitting signals from and into the air as medium. Without proper design of the antenna, the signal generated by the RF systems will not be transmitted and no signal can be detected at the receiver. Antenna design is an active field in communication for future development.For operation in high frequency range one of popular antenna design is the microstrip patch antenna (MPA). In this work, properties of two microstrip, log-periodical and rectangular, patch antennas are studied. Three models of rectangular patch antenna are considered: wideband, U-slot dual-band and double U-slot triple-band patch antennas. By cutting a U-shaped slot in a rectangular patch antenna, an exclusion band appears, filtering out certain frequency range. This is caused by resonance properties of U-slots. For each antenna, a computer model was constructed. Calculated reflection coefficients were compared with measurements. By analyzing antenna input impedance vs. frequency and current distribution, conclusions are drawn about role and importance of U-slot. By means of computer modeling, a method allowing optimization of geometrical size of a log-periodic printed antenna AARONIA AG HyperLOG 60100 was considered. According to it, dipoles are inclined to the central axis by α angle. Computer simulations were used in order to investigate two cases: for α = 30° and 45°. It is shown that antenna properties: reflection coefficient, input impedance and gain change insignificantly as a result, while antenna width is reduced significantly (by 22%). The research also describes how log-periodic printed dipole array antenna is combined with U-slot technique in order to introduce a notch-filtered frequency band in antenna bandwidth (3.1GHz - 11GHz). Dependence of antenna VSWR property on position of U-slot is also investigate in this work. All computer models were constructed and calculated by means of EM simulation software EMCoS Antenna VLab and EMCoS MTEC VLab. This work underlines the importance of using computer simulation in antenna design and optimization. These means allow quickly and accurately predict properties of a desired antenna. Modeling also provides the way to optimize existing antenna designs and prepare them for manufacturing.

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პრეზენტაცია: ბრტყელი და დაბეჭდილი ანტენების გამოკვლევა და ოპტიმიზაცია [ka]
ნაშრომი: ბრტყელი და დაბეჭდილი ანტენების გამოკვლევა და ოპტიმიზაცია [ka]