Abstract: Transmission lines have variable characteristic impedance and length which may also be integrated with modulators and switches. The external electrical voltage controls the number of loads connected to the transmission line as well as connecting required loads to the transmission line and to modulate the value of a load connected to the transmission line. The transmission line includes several twin-conductor transmission lines where one conductor (2) is a main conductor. The other conductors (11), including those with different lengths, are either connected to conductive parts (1) or spaced by a gap from the conductive parts (1). The transmission lines form an ohmic contact with a semiconductor layer (4) having an electronic or hole-type conductivity with a pre-formed non-rectifying contact. The conductive parts (1) may be formed at the beginning or at the end of the transmission line or, alternatively, at the beginning and at the end of the transmission line.

Abstract: The semiconductor device comprises a low-conductivity or insulating layer (5) on one surface of which is formed a conducting section (6) while the other face is provided with a hole- or electron-type semiconductor layer (1) with an ohmic contact. A semiconductor or metal layer (2) is provided on the surface of the semiconductor layer and with (1) forms a p-n junction or Schottky barrier with another ohmic contact. The choice of the alloy cross section and thickness of the layer (1) is restricted by the condition that said layer or part of it must be fully depleted by the basic charge carriers until breakdown of the p-n junction and/or the Schottky barrier when the latter is subjected to an external bias determined by the inequality shown in the application. The p-n junction and/or Schottky barrier can be formed with a non-homogeneous dopant section along a selected X direction on the surface of the layer (1).