In Apple's case, the company got too cute and wrapped the antenna around the outside of the casing to improve the strength of the antenna. While HTC was not as blatant in its antenna design, the Taiwan based firm used a large metal battery cover which has some plastic parts that act as an antenna. When covered by your hand, it affects the performance of the radios inside the unit-especially the Bluetooth and Wi-Fi radios.
To appease customers, Apple ended up offering free rubber bumpers and cases to iPhone 4 buyers. The rubber prevented human contact from interfering with the antenna, which caused the attenuation. Since word about the death grip happening on the HTC Sensation is so far very limited, it might require some more problems to appear after a launch in the U.S. before the manufacturer feels compelled to offer a solution. The HTC Sensation 4G is expected to launch in the States via T-Mobile on June 15th, as we reported. But the model has already hit the market overseas, and if anyone using the handset has experienced the death grip and the loss of signal, let us know by leaving a comment in the box below.
source: GSMArena via NordicHardware (Translated)