<p>I can give you a list of related fields:</p>
<p>software design (applications and os): computer science, software engineering (which is taught in both computer science and computer engineering undergraduate level), and computer engineering</p>
<p>communication-wise: electrical engineering, computer science
iPhone product: mechanical engineering, electrical engineering
electronic components: mechanical engineering, electrical engineering, computer engineering</p>
<p>also notice that physics, chemistry, biomedical science, material science, and mathematicians are also involved in the design process. </p>
<p>I can continue to break down the subjects, but I think this is enough.
Mechanical engineers mostly deal with the product design, while the electrical engineering mostly deal with the electronic components. Computer engineering are said to deal with computer architecture and hardware application (in terms of software), and at the same time computer science (mostly software engineers) do the application and system developments.</p>
<p>The electrical engineering can break down into many sub-fields. Computer engineering is not really any expertise. But it allows you, as an undergraduate to explore variety of things before going to a graduate school. As a computer engineering student, I suggest you to look at the sample cirrumulam of a computer engineering degree. I also double major with standard physics and mathematics, and I believe with these two other degrees I can go on to graduate school and study physics. Physics is really important. When we finally talk about quantum computing, computer science, physics, mathematics, and electrical engineering all come together. </p>
<p>To understand how iPhone is designed, I suggest you to check out how a microprocessor is designed. I did a paper last semester. I was impressed by the technical details.</p>