This research focuses on a new powerful front-end able to reject environmental noise for capacitive sensors. Capacitive sensors can be used for indoor localization and so they can be adopted in many location-based services that improve life quality and safety. Room occupancy information can help reducing energy consumption by controlling the ambient temperature, lighting and water. Also, monitoring human activity for extended periods can detect behavioral changes, which can help recognizing the early onset of diseases like Parkinson disease. Moreover, presence monitoring systems can also be used to detect unauthorized intrusions. Capacitive sensors, operating in load mode, use just one-plate transducer and the human body as a constant-potential plate.