Control grid Control grid The control grid is an electrode used in amplifying thermionic valves (vacuum tubes) such as the triode, tetrode and pentode, used to control the flow of electrons from the cathode to the anode (plate) electrode. The control grid usually consists of a cylindrical screen or helix of fine wire surrounding the cathode, and is surrounded in turn by the anode. The control grid was invented by Lee De Forest, who in 1906 added a grid to the Fleming valve (thermionic diode) to create the first amplifying vacuum tube, the Audion (triode). In a valve, the hot cathode emits
Xiaodong Wang (electrical engineer) Xiaodong Wang (electrical engineer) Xiaodong Wang () is an information theorist and professor of Electrical Engineering at Columbia University. He earned a BS degree in electrical engineering and applied mathematics from Shanghai Jiaotong University, an MS degree in electrical and computer engineering from Purdue University, and a PhD from Princeton University in electrical engineering. He formerly served as assistant professor of Electrical Engineering at Texas A&M University before he joined Columbia as an assistant professor in January 2002. He is a Fellow of IEEE and an ISI Highly Cited author. He has won numerous prestigious awards, among them the National