Electro-thermal simulation of micromachined power sensors at dc and microwave frequencies

In this paper a theoretical simulation model for characterization of the electrical and thermal behavior of micromachined power sensors at both the dc and high frequencies (microwave and millimeter waves) is developed. The sensor fabrication techniques is based on bulk and surface micromachining of AlGaAs/gaAs heterostructures. The simulation is based on the solution of the coupled electromagnetic field and heat transfer equations, using hybrid finite-element/finite-difference techniques. The model can be used as an effective tool for adjustment of design parameters, such as geometric configuration of the sensor resistive element, and arrangement of thermocouples around the resistor for optimum sensitivity and noise figure. Simulated results were compared with experimental measurements with good agreement.