The role played by phasor measurement units (PMU) in power grid monitoring systems today showcases the importance and usefulness of this device. There is a significant challenge regarding the design and implementation of PMUs today. This challenge stems from the closed source philosophy employed by commercial PMU vendors who strongly protect their hardware and software designs keeping it away from researchers. This philosophy has motivated a number of researchers to develop their own PMU devices. This thesis presents the design and implementation of a PMU device utilizing off-the- shelf components to estimate power system parameters such as voltage magnitude, phase angle and frequency with key design information extracted from the OpenPMU group and the IEEE C37.118-2011 standard. The functionality of the PMU was tested by performing important power system experiments which compared measured result of voltage magnitude, phase angle and frequency of a balanced three phase signal from a rapid prototyping system with estimated results from PMU. The conducted experiments confirmed that the PMU could estimate voltage magnitude, phase angle and frequency approximately equivalent to the measured quantities of the input signal.