Cavity backed rectangular spiral antenna

Image of the Cavity backed rectangular spiral antenna.

This antenna is the rectangular version of the Cavity-backed Archimedean spiral antenna and is intended to be used where a square mounting footprint is required. It has the advantage that it can operate in a slightly lower band than an Archimedean spiral constrained to the same space, but the Rectangular spiral shows degraded axial ratio and irregular performance across the band (as shown in the graph images below).

Comparison between the Cavity backed rectangularspiral and Self complimentary spiral designed at 5GHz.