Apple has used Infineon baseband chipsets in all its iPhone models as well as the current iPad. A new report from China's Commercial Times (Google translation), however, suggests Apple will drop Infineon in favor of Qualcomm for the fifth-generation iPhone hardware.

Intel has tried to get a piece of the iPhone pie since the device was released, suggesting that its Atom platform was better suited for smartphones than ARM. However, Apple has traditionally favored its own customized ARM processors over Atom for its mobile devices. With Intel's recent acquisition of Infineon's wireless division, Intel effectively bought its way into the iPhone and the iPad.

There's little to suggest that Apple has any issue with the merger; Intel CEO Paul Otellini told Fox Business two weeks ago that Apple CEO Steve Jobs was "very happy" with the deal.

The Infineon wireless division produces baseband hardware for UMTS-based 3G technology, as well as LTE and WiMAX, but the company doesn't produce CDMA-compatible chipsets. For the long-rumored CDMA-equipped iPhone expected to launch this January, Apple most likely turned to top CDMA baseband supplier Qualcomm.

According to the Commercial Times report, Apple's work with Qualcomm on a CDMA version of the iPhone 4 led it to choose the company to be the sole baseband supplier for the fifth-gen iPhone. AppleInsider noted that some analysts believe moving to Qualcomm is the right move for Apple, since it could reduce Apple's reliance on a "single supplier," but that argument doesn't make much sense if Apple is merely switching from one single supplier to another.

What may have sealed such a deal, though, is a chipset that Qualcomm first announced last year capable of connecting to LTE, CDMA/EV-DO, and GSM/UMTS wireless networks. Such a baseband chipset could allow Apple to produce a single iPhone model compatible with 4G and 3G networks practically anywhere in the world. Though the US domestic market is an obvious place where CDMA compatibility would come in handy, other markets such as China Unicom or SK Telecom in Korea would also benefit from CDMA compatibility.

The chipset is also compatible with Simultaneous Voice-Data Operation (SV-DO), which could let users on CDMA networks like Verizon to use voice and data simultaneously. That capability is currently only available to uses on UMTS networks like AT&T, though Verizon is rumored to be looking at supporting technology to do the same.

Though Qualcomm promised the chip would be available from prototyping in mid-2010, that was likely too late for Apple to adopt it for an upcoming CDMA version of the iPhone 4. If Apple decides producing separate GSM and CDMA iPhones are the best strategy for sales, it has no good reason to dump Infineon/Intel baseband chips. On the other hand, if Qualcomm can deliver on the promise of its mixed-mode chipset, Intel could once again find itself holding the short end of the iPhone stick.