Modulation techniques of the SAW sensor's echo in accordance with the physical phenomena

Lead Research Organisation: Imperial College London
Department Name: Electrical and Electronic Engineering

Abstract

It is already known that the centre frequency of the surface acoustic wave is determined by the shape and spacing of the IDT and its fingers. For a simple IDT structure the centre wavelength and thus frequency is determined by the spacing between consecutive positive and negative electrodes. Thus by straining the material in the direction perpendicular to the electrodes, measurable frequency modulation will occur. It is yet to be researched and understood how other physical phenomena allow wave modulation. Moreover, various transducer techniques shall be examined (e.g. 3-phase IDT, finger withdrawal,varying finger overlap etc.) to achieve the best results. It is known that by converting EM wave into acoustic one the IDT excites more modes than it is desired. More specifically bulk waves can be observed, however they are undesired as they contribute to energy loss. Other modes will also be excited and the key challenge will be to minimize the effect of the slowest ones on the overall system accuracy. Moreover, guided acoustic waves shall be considered and examined to evaluate their sensitivity to the aforementioned stimuli, and whether mode spreading (due to most likely laminated structure) can be contained. Finally, other sensing options shall be considered, e.g. slow wave structures. To achieve all of the above simulation models shall be built and tested.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509486/1 01/10/2016 30/09/2021
2030265 Studentship EP/N509486/1 01/10/2017 31/08/2021 Jakub Szypicyn
 
Description With a use of memristors we have shown that it is feasible to build analogue reconfigurable electronic blocks, with functions which were until now reserved for digital systems such as FPGA.
Exploitation Route Precise analogue computation units may be realised with arbitrary precision. Furthermore our finding allow to build complex differential equation solvers, which would operate at a fractional cost of modern day digital systems.
Sectors Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Electronics