Low-Noise Microwave Devices: AlGaN/GaN High Electron Mobility Transistors and Oscillators

Noise and transport properties of state-of-the-art AlGaN/GaN high electron mobility transistor (HEMT) heterostructures are analyzed with respect to high-frequency oscillator applications for different dissipated powers. The phase noise of a monolithic microwave integrated circuit oscillator based on the best choice AlGaN/GaN HEMT amplifier was investigated. A low level of the phase noise of the oscillator was registered. The up-conversion factor was found to be as low as 15 MHz/V for a frequency offset of 100 KHz, demonstrating that AlGaN/GaN HEMTs offer an excellent potential for a wide range of microwave applications.