0.1-2GHz spiral antenna design?

[flaw]

Hi,
I'm currently looking at 2-arm archimedean spirals as a possible antenna design in the frequency range 0.1-2.0 GHz. Any thoughts on this or any other possible designs for this frequency range.

Thanks in advance.

 

[flatulent]

This is a good choice if you want the beamwidth to be relatively constant over the frequency range. A fixed aperture type will have a narrowing beamwidth with increasing frequency. A logperiodic type will have a fixed beamwidth that is directional which you may not want. Also the spiral and log periodic are planar but need to be mounted in different ways. The fixed aperture is three dimensional. These physical characteristics may not fit into your system requirements. Note that the log periodic will stick out and the spiral will be conformal.

 

[flaw]

i'm looking at conformal applications. thanks for your reply!

 

[flatulent]

One further thing to consider is what is behind the conformal antenna. This will affect the impedance and the radiation pattern. One way to fix these is to have a cavity backing. That is a five sided metal box. If what is behind your antenna is homogeneous like a building wall that is not conducting this cavity is not necessary. If there are electronics some feedback interaction will occur.