Resonant-Tunneling-Diode Terahertz Oscillator Using Patch Antenna Integrated on Slot Resonator for Power Radiation

In this paper, we proposed and fabricated resonant-tunneling-diode (RTD) terahertz oscillators integrated with slot-fed patch antennas to extract output power without using typical Si lenses. A square patch antenna with a 170 μm-long side was fabricated on a 7 μm-thick benzocyclobutene (BCB) layer stacked on an RTD with a slot resonator. The RTD oscillated at ~ 510 GHz, and an output power of ~ 40 μW radiated in the upward direction without the Si lens. An equivalent circuit model was proposed to estimate the output power, and the circuit parameters were derived from the calculated admittance by electromagnetic simulation. The dependence of the output power on the side length of the patch antenna agreed with the theoretical calculation. Higher output power was expected with the optimization of BCB thickness and RTD with a high current density. The radiation pattern was measured, and a directivity of 7 dBi was obtained.