Introduction

The invention relates to a system for the wireless measurement of different quantities. Such system is composed by a passive circuit containing a resistive-transduction sensor and a simple electronic readout unit. The invention comprises also a measurement method to determine the value of the quantity of interest starting from a reading of system electrical impedance.

Technical features

The system of the present invention is composed by two parts. The first part is a circuit made only by passive elements, among which there are an antenna and any resistive-transduction sensor. Therefore, different quantities can be measured, according to a specific application. Furthermore, the passive circuit can be fabricated through low-cost additive technologies. The second part is an electronic readout unit. It is equipped with another antenna that couples with that of the passive circuit, allowing for circuit power supply without adding any battery to the circuit and the wireless measurement of the quantity of interest. In addition, it presents also the electronics needed to read system electrical impedance (in particular, its real part) and for a proper treatment of the generated reading signal. Finally, the unit implements a method that allows determining the value of the quantity of interest from impedance reading.

Possible Applications

• Industrial field: process control;
• Transportation sector: monitoring the conditions of the means of transportation;
• Building sector: structural health monitoring of buildings or infrastructures;
• Food: monitoring food and beverage quality;
• Medical field: monitoring vital parameters.

Advantages

• Possibility of monitoring different quantities;
• The use of batteries inside passive circuit is avoided;
• Wireless measurement of the quantity;
• Possibility of measuring in hermetic environments;
• Low-cost fabrication of disposable passive circuits;
• Measurement applications inside human body.