Like other professors, I get a very large number of email requests about applying to graduate school. In general, I will not be able to reply - except for a very few exceptionally excellent applicants per year- and for this I apologize. It does not reflect on your abilities as a researcher, or even on my interest in having you as a graduate student; it is simply a result of an inbox overloaded by bulk emails about graduate school applications.
In any case, do not be discouraged. You should still consider applying to UCSD. The application procedure and details can be found on the ECE department webpage.
Good luck with your application.