A CMOS digital microcircuit, utilizing sub-micron technology, was designed for the purpose of providing integrated control circuitry to an array of high-voltage micro-electromechanical systems (MEMS) switch based phase shifter devices. The grid of MEMS phase shifters is part of a phased array antenna system. The phase of each element of the array is controlled via the CMOS microcircuit. This paper presents the design, physical layout, and the measured test results for CMOS digital control circuit that has been fabricated using the MOSIS Integrated Circuit Fabrication Service. The circuit converts serial data to parallel outputs to reduce number of control lines and lower the cost of wiring the phased array. In addition, discrete digital control circuitry for loading phase shifts into each MEMS device is presented.
Infrared (IR) techniques can accurately measure temperatures with high spatial resolution, on the order of a few microns resolution. In microelectronics, however, a device’s hot spot, the junction temperature, is a small fraction of a micron. Accurate prediction of junction temperature is critical for reliability and thermal management. This paper presents an accurate closed form model for the junction temperature as a function of device geometry. Based on knowledge of the temperature profile it is possible to reverse the averaging inherent in the IR measurement and obtain the junction temperature accurately based on IR microscopy. This paper illustrates this approach for the case of field effect transistors (FETs) and applies it to several actual measurements.