High power THz oscillators with offset-fed slot antenna and high current density resonant tunneling diodes

We report experimental and theoretical results on the increase in output power of resonant tunneling diode (RTD) oscillators in sub-terahertz (THz) range with an offset-fed slot antenna and high current density. Theoretical analysis shows that the oscillation frequency increases with an offset from the center of the slot antenna. Output power also increases with the offset up to the point of the best impedance matching. As the result of calculation, the oscillation at 600 GHz with the output power of 610 muW is expected for a single RTD with high peak current density (18 mA/mum
²
) and an offset structure. In a preliminary experiment, an output power of 150 muW was obtained at 271 GHz with peak current density of 7 mA/mum
²
.