Sökning: "Acoustic devices"
Visar resultat 1 - 5 av 81 avhandlingar innehållade orden Acoustic devices.
1. AlN Thin Film Electroacoustic Devices
Sammanfattning : Recently, the enormous growth in personal communications systems (PCS), satellite communication and various other forms of wireless data communication has made analogue frequency control a key issue as the operation frequency increases to the low/medium GHz range. Surface acoustic wave (SAW) and bulk acoustic wave (BAW) electroacoustic devices are widely used today in a variety of applications both in consumer electronics as well as in specialized scientific and military equipment where frequency control is required. LÄS MER
2. Acoustic and afterload evaluation of left ventricular assist devices
Sammanfattning : Background: Heart Failure is a serious condition with consequences not only for the individual patient but also for the society with a 5-year mortality rate of 45-60%, and a substantial economic burden. The estimated prevalence in Sweden is 2.2% and the age adjusted prevalence increases with higher age. LÄS MER
3. Computational analysis and design optimization for acoustic devices
Sammanfattning : This thesis focuses on material distribution topology optimization for acoustic waveguides. The limitations of the material distribution approach are discussed in the context of acoustic waveguides with extensive viscous and thermal boundary losses. LÄS MER
4. Studies of acoustic waves, noise and charge pumping using single-electron devices
Sammanfattning : This thesis covers a range of experiments on single-electron devices, electrical circuits that utilize the discreetness of the electron charge. The Single-Electron Transistor (SET) is of special importance among these, being the most sensitive electrometer demonstrated, and sufficiently mature to serve as a building block in sensors and detectors for physical phenomena that can be transformed into charge signals. LÄS MER
5. Studies of the Reactive Sputtering Process and its Application in Electro-Acoustic Devices
Sammanfattning : Electro-acoustic devices such as surface acoustic wave (SAW) and bulk acoustic wave (BAW) devices have been in commercial use for over 60 years and can be found in applications ranging from specialised scientific and military equipment to consumer products, such as mobile telephones, TV and radio receivers, etc. Today by far the largest market for electro-acoustic devices is the telecommunication industry which annually consumes approximately three billion acoustic wave filters for frequency control alone. LÄS MER