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This paper builds a complete analytical model for self-assembling microwave power sensor with thermopile and curled cantilever beam. The power sensor consists of a thermoelectric power sensor for low power detection from 0.1 mW to 100 mW and a capacitive power sensor for high power detection from 100 mW to 800 mW. The curled cantilever beam is designed to improve the dynamic range and microwave performance of the power sensor. The analytical model includes an electromagnetic model, a static mechanical model, and a stationary heat transfer model. The electromagnetic model takes the S-parameter of indirect-heating thermoelectric power sensor into consideration. The static mechanical model considers the fringing fields between the curled cantilever beam and the measuring electrode as well as the initial curling induced by the stress gradient. The experimental results show a good agreement with the theory and validate the effectiveness of the presented models. Furthermore, good performance of the power sensor has found. The measured return loss is lower than −25.5 dB at 8–12 GHz and the output of the power sensor has good linearity with the incident radio frequency power up to 600 mW. [ABSTRACT FROM AUTHOR]

In this paper, a numerical model is established to describe the effect of temperature on the packaged thermoelectric power sensor in different environments. The thermal conductivity of the GaAs substrate and the Seebeck coefficient of the thermopiles both change with the surrounding temperature and then influence the output voltage of the sensor. The return loss of the packaged power sensor is measured to be −20 dB at 10 GHz and close to −12 dB at the edge of X-band. The temperature experiment is performed from 273 K to 363 K in the temperature chamber. An agreement between the measured results and the presented model is obtained and the temperature dependence factor is close to 0.15 mV/K at 10 GHz under the incident power of 50mW. Furthermore, calibration of the output voltage is accomplished from 273 K to 363 K and the compensated power with respect to the surrounding temperature is also recorded under 50mW. [ABSTRACT FROM AUTHOR]

In this paper, a novel wind speed sensor with dual layer inductors is proposed to realize improved sensitivity for the first time. Two inductors with same structure are fabricated on front and back surface of the flexible substrate. When the wind blows towards the substrate, the two inductors on both sides bend because of wind pressure. Consequently, the total inductance variation, as a measure for the wind speed, can be increased effectively because of mutual inductance effect. The proposed anemometer is fabricated on polyethylene terephthalate (PET) substrate. Wind speed experiments are performed in the special wind tunnel and the LCR meter is applied to record the inductance variation. It demonstrates that, compared to single-layer inductors, the dual-layer design can achieve a quadruple sensitivity for the wind speed up to 11.2m/s. The reason is that the mutual inductance contributes to the total variation equally as the two self inductance. [ABSTRACT FROM AUTHOR]

• Finite element simulation of miniaturized housing structure for 3D packaged MEMS thermal wind sensor model. • Experiments are also done firstly, an agreement between simulation and experiment is obtained. • Provide a reference for the design and manufacture of MEMS thermal wind sensor miniaturization package. [Display omitted] This paper, for the first time, investigates the effects of miniaturized housing structure with various parameters on micro-electro-mechanical systems (MEMS) thermal wind sensors by simulation and experiments. Pillar diameter, number, height and curve-shaped top cover with different radian are considered to find out their influence on sensors performance. In the simulation, finite element method (FEM) software COMSOL is applied to simulate the 3D packaged sensor model. Then sensors with different housing parameters are tested in the wind tunnel based on thermal calorimetric principle, which uses flow-induced temperature gradient between symmetrically distributed thermistors to represent wind speed. An agreement between simulation and experiment is obtained, and the results demonstrate that the device's performance can be improved with smaller pillar diameter, more pillar number, and smaller pillar height. Moreover, the curved roof is designed, which provides a possibility for high wind speed measurement. [ABSTRACT FROM AUTHOR]