Another Antenna Engineer on the iPhone
Spencer Webb at AntennaSys has written a good post on the iPhone antenna problems. What’s he’s said about detuning and attenuation is very similar to what I’ve said in other posts. I doubt this is because he reads my blog, it’s more likely because we’ve both had similar experience with handsets before and know many of the same things.
I have been thinking about this more though, and there is a possible explanation for why damp hands may cause the problem. As I said earlier at GHz frequencies damp hands don’t conduct well. But, what if the problem is at much lower frequencies? It could be that the WLAN/BT/GPS antenna is polluted with low frequency interference in the KHz or MHz region. Then, when the user puts a damp finger over the gap that interference is conducted to the cellular antenna. This would only cause a problem if the cellular antenna radio were sensitive to the low frequency interference, that shouldn’t happen but it could happen if mistakes in the design were made.
That would be a very odd cause though, I still think detuning is more likely.
Tags: Handsets, Integration, Slot Antennas