antenne rothammel
Dear david21,
Let's see if I can answer your queries, based upon my limited experience with bowties...
1-what is the advantages of bowtie antenna?
Bowtie antenna is a balanced antenna, which means you will expect low cross-polarisations. It is broader in bandwidth when compared to the normal wire dipole, which can be led further if you plan to make a broadband array.
2-in which frequencies is it used?
Oh! It can be used at any frequency! Just ensure that the side of the bowtie-triangle is a quarter-wavelength to the lowest frequency of interest. So technically, quarter-wave plus quarter-wave will make it a half-wave-length dipole!
3-how should feed it?
Like some forum-threadders say, you can feed it with coaxial lines (but this time round you gotta find out what is the optimal height your radiators should be to the ground plane), or you can feed it via microstrip transmission lines.
4-whats the design formulas for bowtie antenna(for example relationship between antenna dimention and angle with frequency)?
I think I just casually mentioned about the dimension criteria as above. As for the flare angle, the basic knowledge goes that the broader the angle, the broader the bandwidth. 60 to 90 degrees are good try-outs!
5-is it a wideband antenna or not?
Contrary to what most people would say, I prefer to call it BROADBAND. Anything which has a frequency response match of less than an octave (obviously must be more than just a few percent, e.g. 5%), is broadband. Anything more, is wideband. This is just my technical preference. It helps to not mislead people.
Hope these helps.
BR,
Dave