There are a lot of opportunities for doing phd from USA. You do not have to go through the general SAT exam to get into research, but you might have to give IELTS for basic entry. You can browse through the courses offered by the different colleges and choose your field. Apply to the college and answer the tests. There you will be guided to the scholarship schemes. For more details : https://studyabroad.careers360.com/articles/how-apply-for-phd-in-usa