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about helix antenna design
Hi people:
Does anyone could tell me how to calculate the number of turns required by given frequency? e.g. 2.4GHz. What are the factors that going to effect the turns? It would be so great if you can list some reference. Cheers! |
about helix antenna design
Does anyone could tell me how to calculate the number of turns required by given frequency? e.g. 2.4GHz. What are the factors that going to effect the turns? It would be so great if you can list some reference. Cheers! ==================================== What type of helix do you want? End-fire or broadside radiation pattern? They are altogether different in construction. |
about helix antenna design
wrote in message oups.com... Hi people: Does anyone could tell me how to calculate the number of turns required by given frequency? e.g. 2.4GHz. What are the factors that going to effect the turns? It would be so great if you can list some reference. Cheers! There is quite a bit of on-line info on 2.4 GHz helix construction, and we built two of the versions that have the most complete photo and detail coverage (33mm and 42mm form dia). Neither worked worth a damn, despite all the effort put into their construction. Then we built the Biquad, which worked very well, and finally the can-type waveguide or "Cantenna" was the simplest and worked the best (use a 3/4 liter can that's 84mm dia, and at least 145mm long). The helix might be good if you have the ability to construct a self-supporting bare-wire helix, but the types wound on PVC pipes with vinyl insulated wire just don't work - - worse, actually, than the simplest 1/4-wave whip. Use a Wi-Spy Spectrum Analyzer to test performance with the antenna under test connected to your wireless router. A more accurate (but more expensive) arrangement is to use the Wi-Spy and an internal coupling antenna inside a shielded box, with a variable attenuator good to 2.4 GHz between the antenna under test and the Wi-Spy. Using this configuration, my results put both the Biquad and 84mm cantenna at +6dB, a 1/4-wave whip at 0dB, a 1/4-wave whip and groundplane at -3dB, and both Helicals at -7 dB. The Cantenna has better directionality and so was preferred over the Biquad. Chuck, W6PKP |
about helix antenna design
I think i would like to choose end fire pattern. because it's
construction is relatively noncritical. Cheers! Reg Edwards wrote: Does anyone could tell me how to calculate the number of turns required by given frequency? e.g. 2.4GHz. What are the factors that going to effect the turns? It would be so great if you can list some reference. Cheers! ==================================== What type of helix do you want? End-fire or broadside radiation pattern? They are altogether different in construction. |
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