The Investigation Of Thermal Characteristics Of Gaas-based Microwave Power Device And High Frequency Anti-osillation Circuit

Microwave power semiconductor devices having a significant feature in the highfrequency, high-power applications, the application in modern society has become increasingly widespread, such as communications, aerospace, computer signal processing are involved. However, under high power dissipation, the device selfheating effects occur, the active region temperature will be higher, resulting in a decline device electrical characteristics and the device life. Thus, accurate measurement of the device temperature and constituting of the thermal resistance are the essential role of the device life and reliability. In this paper, using the electrical temperature sensitivity method to measure the channel temperature of the device, based resistance tester of our lab, testing the microwave power semiconductor devices thermal resistance, as well as the design of the anti-self-excitation circuit.The research work includes the following aspects:1. Based on microwave transmission and impedance matching theory, design antiself-excitation circuit and measuring AlGaN/Ga N HEMT, respectively. Resolve the signal crosstalk and self-oscillation itself produced. Application of our laboratory resistance tester, complete resistance measurement devices and other related experiments, and proposed several ways to inhibit the elimination of self-excited oscillation circuit.2. Based on the electrical temperature sensitivity method to measure the channel temperature of the device, using our lab thermal resistance tester to research the influence of the thermal inhomogeneity to the device thermal resistance. We choose AlGaAs/InGaAs pHEMT to complete the experiment. Temperature coefficient and temperature-sensitive parameters have been measured. To ensure the device is formed in the same heat unevenly distributed, we placed the device on a heated platform, and applying the same power, different voltage and current ratio. The result shows that different drain-source voltage will cause the device thermal resistance changed. Use infrared cameras to monitor the device surface temperature changes, and compared with the electrical measurement method3. Based on the principle of resistance measurement tester, changes in test conditions, continuous pulse excitation is applied repeatedly, measuring junction temperature in different duty cycles of a single pulse at the junction temperature and track junction temperature changes with the times of pulses, research transient thermal resistance device under different duty cycle pulse.4. Take advantage of the ISE-TCAD software to simulate the device thermal inhomogeneity. Simulated the electric field distribution inside the device at different drain-source voltage, and explore the reasons causing internal thermal resistance of the device at equal power to change.