for the tech interview, the engineer asked me the question regarding Oscilloscope. More specifically he asked me if I know what is going on when Oscilloscope's frequency passed certain frequency that machine can display on the screen. If you keep turning the knob the increase the frequency, in somehow it falls into totally different phases. He asked me the explain it. (which I can not)
and he asked me about Fourier Transform question. Basically he gave me an equation and let me transform it to meet the spec.
second parts of the interview is more in comfortable environment. It was all general questions you can think of in any company interview.