Abstract: The invention relates to a device (1) for measuring the state of polarization of an incident wave of frequency 10 GHz to 30 THz, comprising a field effect transistor (2), a reception antenna (3). According to the invention, the antenna parts (31, 33) detect a component of polarization of the wave, collinear with a direction (X) causing in the transistor (2) an alternating detection voltage (Us), the parts (32, 33) detect a component of polarization of the wave, collinear with a direction (Y) causing the appearance in the transistor (2) of an alternating detection voltage (Ud), the transistor (2) being designed to generate, as electrical detection signal (?U) between the source terminal (21) and the drain terminal (22), a DC detection voltage (?U) a part of which is determined by the state of elliptical polarization of the wave by interference in the transistor (2) between the alternating voltages (Us, Ud).

Abstract: The purpose of the present invention is to improve the efficiency of conversion between terahertz electromagnetic wave energy and direct current energy via plasma waves in a terahertz electromagnetic wave conversion device with a field effect transistor structure. This invention has an HEMT structure having a substrate, an electron transit layer, an electron supply layer, a source and a drain, and includes a first and second group of gates. The gate length of each finger of the first group of gates is narrower than the gate length of each finger of the second group of gates, and each finger of each group of gates is disposed between the source and the drain on the same cycle. A first and second distance from each finger of the first group of gates to two fingers of the second group of gates adjacent to each finger are unequal lengths.

Abstract: The invention relates to a device (1) for measuring the state of polarization of an incident wave of frequency 10 GHz to 30 THz, comprising a field effect transistor (2), a reception antenna (3). According to the invention, the antenna parts (31, 33) detect a component of polarization of the wave, collinear with a direction (X) causing in the transistor (2) an alternating detection voltage (Us), the parts (32, 33) detect a component of polarization of the wave, collinear with a direction (Y) causing the appearance in the transistor (2) of an alternating detection voltage (Ud), the transistor (2) being designed to generate, as electrical detection signal (?U) between the source terminal (21) and the drain terminal (22), a DC detection voltage (?U) a part of which is determined by the state of elliptical polarization of the wave by interference in the transistor (2) between the alternating voltages (Us, Ud).

Abstract: The purpose of the present invention is to improve the efficiency of conversion between terahertz electromagnetic wave energy and direct current energy via plasma waves in a terahertz electromagnetic wave conversion device with a field effect transistor structure. This invention has an HEMT structure having a substrate, an electron transit layer, an electron supply layer, a source and a drain, and includes a first and second group of gates. The gate length of each finger of the first group of gates is narrower than the gate length of each finger of the second group of gates, and each finger of each group of gates is disposed between the source and the drain on the same cycle. A first and second distance from each finger of the first group of gates to two fingers of the second group of gates adjacent to each finger are unequal lengths.