Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 50: III-V Semiconductors II (mainly Arsenides)
HL 50.5: Vortrag
Mittwoch, 28. März 2012, 10:30–10:45, EW 203
Detection of THz Signals with a GaAs Field Effect Transistor — •Sascha Preu1, Sangwoo Kim2, Peter G. Burke3, Hong Lu3, Mark S. Sherwin4, and Arthur C. Gossard3 — 1Lehrstuhl für angewandte Physik, Univ. Erlangen, Germany — 2Tanner Research, Monrovia, CA, USA — 3Materials Department, University of California, Santa Barbara, CA, USA — 4Physics. Dept, Institute for THz Science and Technology, University of California, Santa Barbara, CA, USA
We report on direct detection and homodyne mixing operation of a field effect transistor (FET) far above frequencies where the transistor has gain. The FET consists of a remotely doped AlGaAs-GaAs channel with a two dimensional electron gas. For direct detection, the THz power is coupled to the device via a broadband logarithmic-periodic antenna with a frequency range of about one order of magnitude (50 GHz-500 GHz). The FET rectifies the THz signal along the gated region, providing a DC signal proportional to the total incident THz power. Despite a large impedance mismatch, we achieved a direct detection noise equivalent power (NEP) of 20 nW/√Hz at room temperature at 230 GHz. Further optimization and impedance matching suggests a theoretical detection limit below 1 pW/√Hz. We also investigated a FET under mixing operation with narrowband antennas, resulting in an NEP of 960 pW/Hz at 370 GHz.