Pulsed and transient characterization of THz Schottky diodes

Any non-linear electronic device can be used for the purpose of frequency mixing or multiplication. But when the frequency is very high (in THz band), only few devices can provide acceptable conversion efficiency and low noise performance. GaAs Schottky barrier diodes are preferred and commonly used in heterodyne receivers as a mixing element. However, at higher frequencies the diode size is small which reduces its thermal capability and the self-heating is significant even for small current levels. In this master's thesis different electrical and thermal characterization methods for a diode are reviewed. Limitations of the DC I-V measurement method are identified and a test is carried out to study the feasibility of a new pulsed system for characterization of THz Schottky diodes. The military standard method for thermal impedance testing is studied and suitable modifications to the military standard method are proposed. The transient temperature response of the diode is fitted to an exponential function to extract the junction temperature, thermal impedance and thermal time-constants associated with the internal distribution of thermal resistances and heat capacitances of the diode under test