MEMS Integrated Packaging for RF Circuit Testing and Self Calibration

Abstract

This paper presents MEMS enhanced integrated packaging which provides testing and self-calibration to identify process-related defects and out of specification circuits, thereby enabling the package to calibrate itself in case of faults and defects to designed performance levels. We have developed a novel multi-tone dither test technique where the test stimulus is generated by modulating the RF carrier signal with a multi-tone signal generated using an Arbitrary Waveform Generator (AWG) with additive white Gaussian noise. This test stimulus is provided as input to the RF circuit and peak-to-average ratio (PAR) is measured at the output. For a faulty circuit, a significant difference is observed in the value of PAR as compared to a fault-free circuit. Simulation is performed for various circuit conditions such as fault-free as well as fault-induced and their corresponding PARs are stored in the look-up table. Hardware testing is performed and the results are compared with the look-up table to verify whether the device is fault-free. In faulty circuit conditions, calibration is performed using a tuning circuit which consists of MEMS switches. The entire validation of the design using test technique and self-calibration of the RF circuit is automated using the calibration algorithm. This testing and self-calibration technique is exhaustive and efficient for present-day communication systems.