Thin film bulk acoustic wave (BAW) resonators and filters operating in the GHz range are used in mobile phones for the most demanding filtering applications and complement the surface acoustic wave (SAW) based filters. Their main advantages are small size and high performance at frequencies above 2 GHz. This work concentrates on the characterization, performance optimization, and modelling tech...

High frequency (> 200 GHz) gyrotrons are potentially useful for several important applications, including plasma heating and radar. For electron cyclotron resonance heating of a moderate-size, high power density tokamak power reactor to ignition temperatures, a gyrotron frequency around 200 GHz appears to be necessary. The design of high frequency gyrotrons is discussed. Analysis of overall gyr...

Applications of surface acoustic wave (SA W) and shallow bulk acoustic wave (SBA W) devices are reviewed. SA W-device coverage includes delay lines and filters operating at selected frequencies in the range from about 10 MHz to 11 GHz, modeling with singlecrystal piezoelectrics and layered structures, resonators and lowloss filters, comb filters and multiplexers, antenna duplexers, harmonic dev...

A technique for analysing the sensitivity of a surface acoustic wave (SAW) device is presented, based on the numerically obtained Green’s function. It is applied to devices based on a 36◦-YX LiTaO3 substrate with a ZnO guiding layer. The capability of these devices for gas and liquid sensing is shown by studying parameters such as mass sensitivity and electromechanical coupling coefficient. Dev...

Structural components subjected to high frequency vibrations, such as those used in vibrating parts of gas turbine engines, are usually required to avoid resonance frequencies. Generally, the operating frequency is designed at more than resonance frequencies. When a vibrating structure starts or stops, the structure has to pass through a resonance frequency, which results in large stress concen...

We discuss the design and operation of widely-tunable terahertz sources based on Cherenkov intra-cavity difference-frequency generation in mid-infrared quantum cascade lasers. Laser chips are integrated into a Littrow-type external cavity system. Devices demonstrate continuous terahertz emission tuning at room temperature with a record tuning range from 1.2 THz to 5.9 THz and peak power output ...

OBJECTIVE To evaluate the ability of contrast sensitivity (CS) to discriminate loss of visual function in diabetic subjects with no clinical signs of retinopathy relative to that of normal subjects. RESEARCH DESIGN AND METHODS In this prospective cross-sectional study, we measured CS in 46 diabetic subjects with a mean age of 48±6 years, a best-corrected visual acuity of 20/20 and no signs of...

typically, two configurations are used for energy harvesting, with different advantages: piezoelastic and piezomagnetoelastic. best performance of piezoelastic configuration is limited to its narrow bandwidth around the resonance frequency. if the excitation frequency slightly deviates from the resonance frequency, the power-out is severely reduced. to overcome this, the piezomagnetoelastic has...