A Wireless Passive Pressure and Temperature Sensor via a Dual LC Resonant Circuit in Harsh Environments

Highly Sensitive Reentrant Cavity-Microstrip Patch Antenna Integrated Wireless Passive Pressure Sensor for High Temperature Applications

“…When the pressure increased from 0.25 bar to 3 bar, the resonant frequency varied from 2.03 GHz to 1.76 GHz, presenting an approximately linear relationship with the loaded pressure. An average sensitivity of 981.8 kHz/kPa was calculated to be 50 times greater than the LC based wireless sensor proposed in [3]. But the measured resonant frequency, 2.39 GHz, of the sensor with no pressure load was deviated from the simulated frequency, 1.719 GHz; this is mainly due to the calculation error of the equivalent lumped model, the electromagnetic field distribution error caused by the punched aperture, and the process error during the fabrication.…”

“…We can see that there is a one-to-one relationship between each temperature and the correspondent linear function which can be determined using (10) and (11). For practical application, the pressure can be obtained relying on a method called table lookup on the premise that the temperature is measured in advance via methods proposed in [3][4][5]. It can be seen from Figure 12(d) that the pressure obtained by table lookup is around the referenced pressure with a maximum error of 5.78%.…”

“…It was fabricated in LTCC ceramic with low profile and high integration. Tan et al proposed LC based sensor which can realize temperature and pressure measurement simultaneously, providing temperature compensation for pressure, making it precise for the measurement of the pressure at high temperature [3]. But the lumped circuit has low factor, causing a rapid reduction of the stored energy and a short wireless transmission distance [4,5].…”

Technique for wireless reading of passive microfluidic sensors

“…As a matter of fact the typical interrogation range achievable by sensors integrated in Radio-Frequency Identification (RFID) tags does not exceed few meters and the typical long-range qualification for batteryless RFID tags is around 12 meters [1, 2]. Moreover passive sensors using an electromagnetic transduction (see, e.g., [3][4][5]) allow higher reading range (up to some decameters [6]) but suffer from poor measurement resolution of the physical or chemical quantity of interest compared to their active counterpart.In this Letter we report for the first time a wireless reading technique for improving the measurement resolution of wireless, batteryless and chipless sensors. The technique is applied here for the remote interrogation of the passive microfluidic temperature sensors reported in [7].…”

“…As a matter of fact the typical interrogation range achievable by sensors integrated in Radio-Frequency Identification (RFID) tags does not exceed few meters and the typical long-range qualification for batteryless RFID tags is around 12 meters [1, 2]. Moreover passive sensors using an electromagnetic transduction (see, e.g., [3][4][5]) allow higher reading range (up to some decameters [6]) but suffer from poor measurement resolution of the physical or chemical quantity of interest compared to their active counterpart.…”