First, HR contacted me by email, and I took a phone interview with HR, and then with hiring manager.
After few weeks HR contacted me for on-site interview, but they said no supporting trip for interview and any relocation. However, I accepted it and I went the company with my expenses.
During the interview,
1. talking with hiring manager
2. Written test (From all areas of EE courses, total about 40 problems??, diode circuit, op-amp, transistor circuit calculation problem, signal, UNIX/LINUX commands. All problems were college)
3. Hands-on test: Measurement of voltage, current and something on the their board with oscilloscope and DMM
4. Interview with director
and, finish and returned home.