A PhD is a highly advanced degree that helps graduates become experts within a field. Earning this degree may help students be better qualified for their chosen careers as well as any other professional pursuits they may have.
You can only be in a position to solve advanced engineering problems if you have PhD training in engineering. To be admitted as a doctoral student, one must hold a masters degree in the Engineering or related subject and pass a comprehensive entrance exam.
Education in the United States is mainly provided by the public sector, with control and funding coming from three levels: state, local, and federal, in that order. The common requirements to study at a higher education level in United States will include your admissions essay (also known as the statement of purpose or personal statement), transcript of records, recommendation/reference letters, language tests
Online PhD in Engineering in USA