Apple may design its own LTE chip for the iPhone 6 successor Starting with 2015 iPhone models, Apple may use its custom radio chips, Digitimes reveals, as the company is apparently forming an R&D team to work on baseband chips, which are responsible for handling wireless connectivity on a handset including cellular radios responsible for LTE. Designed by Apple, these chips would be built by Samsung Electronics and Globalfoundaries, according to “industry sources.”