A planar Gunn diode operating above 100 GHz

We show the experimental realization of a 108-GHz planar Gunn diode structure fabricated in GaAs/AlGaAs. There is a considerable interest in such devices since they lend themselves to integration into millimeter-wave and terahertz integrated circuits. The material used was grown by molecular beam epitaxy, and devices were made using electron beam lithography. Since the frequency of oscillation is defined by the lithographically controlled anode-cathode distance, the technology shows great promise in fabricating single chip terahertz sources