Reports are emerging which claim iPhone 3G owners sometimes face a challenge getting a consistent mobile signal when making calls on their phones – and it could be the Infineon chip inside the device that’s too blame, an analyst states.

Apple’s discussion threads are also full of users complaining at poor call quality – and these reports aren’t just emerging in the US.

After reading many of the threads in various forums around the internet, it seems users are complaining not only calls dropping, but applications freezing up.

Nomura Securities analyst Richard Windsor said the problems being reported are “typical of an immature chipset and radio protocol stack,” and that the blame may lie with Infineon, makers of the 3G chipset.

More damning evidence from T-Mobile in the Netherlands, which warned on the company blog: “The 3G coverage of T-Mobile is as good as the competition, there can therefore not lie. We suspect that it is a hardware / software specific issue of the iPhone itself.”