Patent ID: 7397175

Claim:
A solid state thermionic tetrode, comprising: a first substrate having a cavity formed on one side with an insulating layer coating the one side and a surface of the cavity; an anode formed in the cavity and adjacent to the insulating layer; a grid structure, comprising: a first conductive layer formed above the anode in the cavity; a first insulating layer formed between the first conductive layer and the anode; a second conductive layer formed between the first insulating layer and the anode; and a plurality of slots passing through the grid structure to allow passage of electrons therethrough; a second substrate opposite the first substrate having a void formed therein; a cathode disposed between the void and the first conductive layer; a means for heating the cathode; and a seal between the first and the second substrates to enclose the cavity, the grid structure and the void of the tetrode in a controlled environment.