Title :
Bandwidth Enhancement of Low-Profile PEC-Backed Equiangular Spiral Antennas Incorporating Metallic Posts
Author :
Veysi, Mehdi ; Kamyab, M.
Author_Institution :
Electr. Eng. Fac., K. N Toosi Univ. of Technol. (KNTU), Tehran, Iran
Abstract :
This communication examines parasitic coupling to achieve higher bandwidth (BW) and further size reduction for low-profile PEC-backed equiangular spiral antennas. The parasitic loading is realized by metallic posts placed between the antenna plane and metal reflector. The parasitically excited metallic posts can considerably improve the antenna axial ratio at low frequencies as well as make it more rigid in construction. However, in practical applications, the low-profile equiangular spirals, albeit compact, suffer from the lack of a proper planar feed. To obviate this problem, a planar spiral-shaped microstrip feed is proposed.
Keywords :
antenna feeds; microstrip antennas; planar antennas; spiral antennas; antenna axial ratio; antenna plane; bandwidth enhancement; low-profile PEC-backed equiangular spiral antennas; metal reflector; metallic posts; parasitic coupling; parasitic loading; planar spiral-shaped microstrip feed; size reduction; Antenna measurements; Antenna radiation patterns; Feeds; Microstrip; Microstrip antennas; Spirals; Equiangular spiral antenna (ESA); freestanding equiangular spiral antenna (FESA);
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2011.2164194
