[Home - Affordable castings, RF, and microwave products Affordable RF and Microwave Products Affordable RF and Microwave Products Experienced engineers founded SEI, as a company providing high-level expertise of Microwave & RF Components, Connectors, and Adapters at reasonable prices. OUR SERVICES Welcome! Here are some of the many rf/microwave products we offer: SEI was started in Campbell, California in 1990 and is a division […]]