Rubén Caballero, who led Apple’s 5G modem team until January, reportedly warned Steve Jobs that the iPhone 4 would drop calls.
From The Verge:
First, The Information reports he was the driving force behind Apple’s in-house 5G modem efforts — because yes, it seems that Apple is trying to design its own 5G modem to compete with Qualcomm. We can’t read too much into his departure because 5G is ridiculously messy right now and Apple’s at the eye of the storm, so there could have been any number of reasons for him to get pushed out or decide to move on…
But second, Caballero happens to be the same antenna expert who reportedly warned Steve Jobs that the iPhone 4’s antenna design might be prone to dropping calls, and he’s apparently been rising up the ranks since then. His LinkedIn page states he’s been at the company for over 14 years, and a 2018 profile at CNET en Español suggests he and his team have touched every wireless element of every Apple device since.
My take: Interesting guy. As the Verge says, there could have been any number of reasons for him to get pushed out or decide to move on.