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Dielectric constant variation with temperature for different wax samples is analysed with the help of split ring resonators (SRRs). The method employs a simple extraction procedure to obtain the unknown permittivity values from a calibration curve drawn between relative permittivity of standard samples and resonant frequency of SRR with each of the samples placed above it. The wax sample is placed...
We report on the experimental calibration of the temperature coefficient of frequency (TCf) in single crystal 6H-silicon carbide (SiC) microdisk resonators based on a smartcut technology. We vary the temperature (T) from −32ºC to 125ºC while monitoring the undriven thermomechanical multimode resonances of the devices using sensitive optical motion detection. Both torsional mode and flexural mode resonances...
The microwave resonant elements with electronic control on the basis of semiconductors p-i-n diodes are considered. The possibility of the existence a high-Q resonance of E-type in semiconductor p-i-n structures in the microwave range is shown. The dependence of the resonance frequency and the unloaded Q-factor of the p-i-n diode from forward current is investigated. The temperature dependences of...
Throughout our research about lead-free piezoelectric ceramics, we have found that some of lead-free ferroelectric ceramics indicate the excellent piezoelectric properties as compared with PZT-based ceramics under some specific conditions such as high temperature, large amplitude vibration or large mechanical stress. Bismuth layer-structured ferroelectric ceramic, Bi4Ti3O12 (BIT), has high Curie temperature,...
Micromechanical resonators (MEMS resonators) often show a discrepancy between the frequency-temperature (ƒ-T) characteristics they have in open-loop and closed-loop measurements. We show that this discrepancy is due to the nonlinear amplitude-frequency (A-ƒ) effect: the quality factor (Q) can increase by more than a factor of 2 when the resonators go from a high temperature to a low temperature; simple...
In recent years, MEMS gyroscope which is a kind of angular-rate-sensor has been improved greatly. In this paper, the effect of temperature changing on MEMS gyroscope is analysed. An evaluation and compensation platform based on the MCU and PC software has been fabricated. The temperature tests were done and some novel compensation algorithms were presented to fit the temperature curve. The thermal...
In this paper we present the temperature compensation of aluminum nitride (AlN) Lamb wave resonators for a future application to XOs and TCXOs for a frequency ranging from 100 MHz to 1000 MHz. The temperature coefficient of frequency (TCF) for the lowest symmetric Lamb wave mode S0 for AlN plates with h/lambda<0.3 is found to be around -30 ppm/K. A zero TCF resonator is obtained by adding a compensating...
Optical communication systems based on dense wavelength division multiplexing (DWDM) would benefit from the ability to adjust the operating wavelength of a laser transmitter. Previous attempts, including thermal adjustment, etalon based wavelength locking, and various types of optical frequency and phase locked loops such as the Pound-Drever-Hall technique suffer from weaknesses including sensitivity...
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