Search

In this article, a new temperature drift compensation method using variable circuit parameters is proposed for micro-electromechanical systems (MEMSs) thermal wind sensors. Different temperature coefficients of resistance between heating resistor and ambient temperature resistor, together with mismatched resistor, give rise to temperature drift, which has been analyzed. An adjustable resistor is introduced in parallel with ambient temperature sensing resistor, achieving a new equivalent resistance Rs’. The temperature drift can be eliminated by recording the resistance at different temperatures. The sensors were tested in the temperature chamber and their heating power were compared to the calculations. Above all, the speed experiments have been performed in the wind tunnel with the temperature varying from 0 °C to 40 °C. The results indicated that the maximum wind speed errors in constant temperature difference (CTD) mode were close to 1.027, 0.611, and 0.530 m/s for the three sensors after compensation. The maximum related errors are less than 2.70%, 2.17%, and 2.24%, respectively. Compared to the uncompensated devices, the errors have been reduced by about 91.28%, 89.67% and 83.23%, respectively.

The low efficiency of iterative optimization in Microelectromechanical Systems (MEMS) devices is due to their complete separation from interface circuits. In the case of board-level circuits, this problem is particularly evident. To solve this problem, this paper proposes a system-level co-simulation strategy that combines the macromodel of a MEMS device extracted by Verilog-A with board-level circuits, exploring an efficient and accurate MEMS-assisted optimization design method. In order to better adapt to actual interface circuit, the macromodel of sensor is divided into two sub macromodels corresponding to the control circuit and processing circuit. The sub macromodels are coupled with the temperature information. Subsequently, the influence of packaging is investigated based on co-simulation approach. The simulation results show the power consumption is proportional to the heat conductivity of packaging, and the sensitivity is inversely proportional to heat conductivity. Therefore, based on system-level co-simulation prediction, a hollow glass with low heat conductivity is used to encapsulate the sensor chip. The comparison shows good agreement among the results of co-simulation, experiment and finite element analysis. Specifically, the heating power of the latest sensor ranges from 70 mW ~ 150 mW, and the sensitivity has been improved to 16.3 mV/( $\text{m}\cdot \text{s}$ -1). Therefore, this robust system-level co-simulation method has shown its potential in MEMS design and optimization. [2023-0068]

This letter presents a wideband substrate-integrated H-plane horn antenna loaded with a novel E-plane corrugation. Classical substrate integrated waveguide (SIW) H-plane horn antennas suffer from poor impedance matching, large E-plane half-power beamwidth, and strong back radiation due to the thinness of the substrates. A substrate-integrated E-plane corrugation is introduced as an effective solution, implemented using the multilayer printed circuit board technique. The elaborated corrugated SIW horn is well matched with reflection coefficients less than $-$10 dB from 26 to 40 GHz. The back radiation suppression reflected by front-to-back ratios is improved to minimum 20 dB and up to 40 dB in the entire Ka-band. Furthermore, the corrugation reduces the half-power beamwidth of the E-plane radiation patterns successfully, e.g., from 180$^{\circ }$ to 80$^{\circ }$ at 30 GHz, whereas the H-plane patterns are maintained and unaffected. Consequently, the antenna gain is well enhanced. A prototype of the corrugated horn is fabricated and then measured. The measurement is in good agreement with the simulation. The proposed corrugated SIW horn antenna is compact in a planar structure so as to easy integration and array deployment. The wide bandwidth, narrow E-plane half-power beamwidth and low back radiation make it very promising for applications as millimeter-wave probes or handset antennas.