Comparison between iPhone 4 antenna and iPhone 4S antenna

Improving on the external stainless steel, dual-antenna design of its predecessor, the iPhone 4, Apple has redesigned the antenna in the iPhone 4S so that the cellular radio in the phone can alternate between two antennas, depending on which is sending/receiving the best signal. These two antennas form part of the stainless steel band that covers the sides of the iPhone 4 and 4S.

The bands on the iPhone 4 are divided into four antennas, cellular, Bluetooth, GPS, and Wi-Fi. In both the iPhone 4 and 4S, the cellular (GSM) antenna is divided into two. Therefore, if the iPhone 4S is gripped in such a way as to attenuate one piece of the cellular antenna, the radio will switch to the other piece that isn’t being gripped.

The iPhone 4S can support a maximum output theoretically of up to 14.4 Mbps with HSDPA as a result of an upgraded radio chip inside the phone, in addition to being a world phone, so both CDMA and GSM customers can roam internationally on GSM networks. It also supports Bluetooth 4.0.