Terahertz Resistor-coupled Arrayed Resonant-tunneling-diode Oscillators with High DC-to-RF Efficiency using Metal-insulator-metal Capacitor

Resistor-coupled arrayed resonant-tunneling-diode (RTD) oscillators have emerged as promising candidates for high-performance Terahertz sources. Despite various advantages, the DC-to-RF efficiency of such oscillators is still low. The reason is the loss caused by resistors, which form the ends of the slot antennas. This paper presents a method to increase the DC-to-RF efficiency of resistor-coupled arrayed oscillators. Edged resistors at the ends of slot antennas are covered by metal-insulator-metal capacitors, which shunt the currents flowing through those resistors. Thus, the conduction loss caused by edged resistors is reduced. Owing to low conduction loss, high output power is obtained, resulting in a high DC-to-RF efficiency. It is estimated that the proposed oscillator’s output power and DC-to-RF efficiency reach 1.53 mW and 0.44% at 450 GHz, respectively. A high power density of up to 62 mW/mm2 is another advantage of the proposed RTD oscillator. With the improved characteristics, we believe the proposed oscillators could promote various Terahertz applications.