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Image of the Printed rectangular spiral. |
The printed rectangular spiral antenna is a wide band, circularly polarized antenna. The antenna properties are comparable with those of the Archimedean spiral antenna. This geometry is favored above that of the Archimedean spiral in situations where the object on which the antenna is to be mounted is square, since it utilizes the area optimally, at the cost of more uneven performance across wide bandwidths. If space is at a premium, the ends of the arms are sometimes terminated with loads to compensate for the end reflections at low frequency operation. Typical applications of this antenna include Electronic warfare (EW) systems.
The structure consists of four individual rectangular waveguide sections which are connected and separated by a central metallic block which extends the length of the waveguide. Each waveguide is flared in both directions to create an aperture which forms...
This axial-mode helix array consists of four identical helices placed in a 2-by-2 grid, rotated sequentially about their axis, and fed sequentially out of phase.