I know they are in the band around the edge, or at least some are (the Bluetooth antenna I found a drawing for and it’s inside one of the corners). And I know you can see the black lines between them. But which one is where, and where are the feed points? If possible, where are the nodes and antinodes, as they resonate? All this stuff is standard, classic understanding of antennas, but I have spent quite a while looking for it, and not turned up a great deal. The silhouette in Steve Jobs’s slide show, for example, leaves most of this pretty vague.
There are two redundant cellular antennas. They are the metal frame bands at the top and bottom of the phone. They are not inside the bands - the bands are the actual, conducting antennas themselves. The phone dynamically switches between the two antennas, for both transmitting and receiving, based on the receiving signal strength.
The WiFi/Bluetooth antenna is inside the phone in the top left corner, as you noted.
As far as I know, the metal frame bands on the sides are not used as antennas in the 4S.
A diagram is here, from the extraordinarily comprehensive Anandtech review:
Absolute, thanks. I like the anandtech document, but it doesn’t show the GPS antenna. I read somewhere that the GPS antenna is on one of the long sides. I don’t have any images anyplace, though, that confirm this. I also read in several places that the 4S moves the GPS antenna from the band to inside the rear glass face, and wondered if this was a patch antenna (the commonest for GPS). But I have not found any images of this, either.
By the way, I understand that the bands are the antenna elements (at least for the cellular antennas, depending on what is elsewhere), and are not casings that surround them. I meant “in” as for example “the letters are in the word”. In the OP, I might better have said that the antennas are sections of the bands.
If I had to guess, I would say the internal WiFi/BT antenna is used for GPS as well, because I haven’t seen mention of any other antennas. The iFixit teardown has high-resolution photos if you want to look for yourself (mouse over the pictures and click “View Huge”). I do not see any indication of an RF connection to either of the long side pieces:
In the iPhone 4, there were two L-shaped external antennas - one was the cellular antenna, the other was WiFi/BT/GPS (the U-shaped bottom piece on the 4 was not used, IIRC).
A few people have referred me to this, and I’ve been there - nice photos - but unless I am missing something, they do not discuss antennas at all. I understand you suggest I look for myself, and don’t claim they discuss antennas per se. Still, have I missed something there?
GPS/GLONASS functions are built-in to the Qualcomm MDM6610 baseband chip and use the cell antenna(s). The receive antenna may be the top, bottom, or both, depending on signal strength.
