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Omnidirectional and Circularly Polarized Slotted Antenna Array With Increased Bandwidth Performance by Using Nonidentical Waveguide Slots
Author(s) -
Turkmen Ceyhan,
Secmen Mustafa
Publication year - 2018
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/2018rs006635
Subject(s) - optics , beamwidth , omnidirectional antenna , axial ratio , circular polarization , slotted waveguide , physics , turnstile antenna , azimuth , bandwidth (computing) , beam waveguide antenna , radiation pattern , waveguide , helical antenna , coaxial antenna , slot antenna , antenna (radio) , telecommunications , computer science , microstrip
In this paper, the design, production, and results of an omnidirectional and circularly polarized antenna for satellite communication applications such as telemetry or telecommand are explained. The antenna is fed by a special transition structure between rectangular waveguide to circular waveguide in order to provide symmetrical circular waveguide mode of TM 01 and eliminate dominant but asymmetric mode of TE 11 . The radiation part on the antenna has the geometry of inclined waveguide slots placed in a rotationally symmetric way on a circular waveguide and two radially outward parallel cylindrical plates in order to provide circular polarization. In the design of the antenna, nonidentical slots are used on the circular waveguide where half of the total number of slots is reduced to increase the bandwidth of the antenna. The realized antenna is found to give about 5–6% impedance bandwidth around 12 GHz where it is just approximately 2.5% when all slots in array are identical. The usage of nonidentical slots results in degradation of gain variation and axial ratio performances as compared to the antennas with identical slots; however, it still performs gain variation less than 3 dB over full azimuth plane, and axial ratio under 3 dB over full azimuth plane and elevation beamwidth of minimum 50° for the given bandwidth.