Abstract
We report on very high power resonant tunnelling diode (RTD) based monolithic microwave integrated circuit (MMIC) oscillators with 35 mW output power at 11 GHz and 10 mW at 49 GHz. The key to these high powers is the use of an epitaxial layer structure that give devices with large peak to valley voltage span (Delta V) of 1.2 V and the use of large area devices to get large peak to valley current span (Delta I). The low device self-capacitance of 0.25 fF/mu m(2) allows the use of large area devices without limiting the maximum achievable oscillation frequency. All fabrication of the oscillator MMICs was done using low-cost photolithography techniques. The achieved power levels are unprecedented for RTD oscillators and demonstrate the very high-power capability of this technology at microwave and mm-wave frequencies, and show that it could be competitive for the next generation (6G) wireless links and automotive radar applications.