Project Documentation
Sponsored by
Lorand Technologies 
MEMS WIRELESS TRANCEIVER
As the size of electrical components becomes smaller and smaller, the future of electronics lies not in nanotechnology, but in microtechnology. The marketability of MEMS, or microelectromechanical systems, is increasing as the field expands and new applications are developed. Most of the MEMS products developed are sensors which relate changes in capacitance, resistance, or voltage to changes in the environment. Despite the complexity of these devices, they are worthless without a method of reliably communicating with the sensor. In this project, a transceiver will be designed to communicate with a sponsor-provided MEMS sensor that will be positioned on a motor a specified distance away. In this setup, the transceiver will wirelessly communicate with the sensor via a 27 MHZ frequency in order to monitor the health of the motor in a non-invasive manner. Non-invasive testing is typically accomplished by means of small sensors that are positioned within the structure or system and remain there throughout the life of the unit in question. These sensors typically monitor the frequency and amplitude of a system’s vibration and pass these values to a computer for analysis of the data. Unusual or extreme shifts in these parameters can indicate that a system may be malfunctioning or needs maintenance. Non-invasive sensor devices have already been designed and are currently available on the market. However, the available designs operate at frequencies far beyond the ISM band. One of the biggest issues with devices operating at this frequency is interference. To counteract the effects of interference, the transmitter and receiver operate at slightly different frequencies and must perform modulation to communicate. Because pre-existing designs already functions at high frequencies, it is undesirable to modulate these signals to even higher frequencies. To avoid issues caused by operation at higher frequencies, this project aims to communicate with a sponsor-provided MEMS sensor via radio frequencies. This goal is to be accomplished by sending high-power radio signals to the MEMS sensor for excitation before switching to a receiving mode to gather data from the sensor. The response of the MEMS sensor is frequency variant, and this variance in frequency will allow us to determine the overall health of the system. This will be accomplished by taking the received frequency response of the system and applying a fast Fourier transform (FFT) to the signal and looking for frequencies that are outside of the standard value. Once the FFT has been performed on the systems microcontroller, the microcontroller will relay the data to a computer where a graph will be plotted to display the characteristics of the systems status. The completed design package will contain a fully integrated system. The system will consist of a printed circuit board (PCB) with embedded microcontroller that provides bidirectional communication to the sensor through the 27 MHz antenna. The PCB will also be capable of interfacing with the PC via serial USB communication. The system will have a launchable application on the Windows platform to provide the user with system diagnostics. The goal of this project is to create a fully functional and reliable piece of test equipment that will allow the sponsor to easily monitor the health of their systems.