Abstract: A Gunn diode includes an active layer having a top and a bottom, a first contact layer disposed adjacent to the top of the active layer, a second contact layer disposed adjacent to the bottom of the active layer, wherein the first and second contact layers are more heavily doped than the active layer, and at least one outer contact layer disposed at an outer region of at least one of the first and second contact layers, the at least one outer contact layer being more heavily doped than the first and second contact layers, wherein the first and second contact layers, the active layer, and the at least one outer contact layer include a base material that is the same.

Abstract: The invention provides a high gain ultra high frequency amplifier with high output power and low phase shift. This amplifier, whose organization is arborescent, comprises a plurality of series amplification stages (1st to 5th), each stage comprising a plurality of elementary cells. Each cell has only one input but at least two outputs. A cell is, for example, a field effect transistor, with input at the gate and outputs at two drains. The input of the first transistor forms the input of the amplifier. A metalization which joins together all the outputs of the transistors of the last stage forms the output of the amplifier. The transistors are input and output matched by means of microstrip lines, capacities and inductances. The monolithic implantation of this amplifier may, among other things, be provided concentrically about the input transistor or linearly with the transistors of the last stage on one line and those of all the other stages on another line.