Ultra violet radiation controlled non-linear dielectrics

紫外线辐射控制非线性电介质

基本信息

批准号：
EP/E044840/1
负责人：
Neil Alford
金额：
$ 38.01万
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2008
资助国家：
英国
起止时间：
2008 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FE044840%2F1
关键词：
Ultra violet radiation controlled non

项目摘要

The term beam steering means the focussing of a beam of light in order to improve the amount of light reaching a specific target, rather like a searchlight. But to increase the coverage the bean is rapidly modulated - the searchlight is very rapidly swept back and forth. The same principle applies to radio waves and microwaves. This proposal aims to make an array of antennas that can be electronically steered in order to improve this focussing. To achieve this we need phase shifters which are devices that can alter the output signal phase on the application of a voltage. In comparison with current communication systems, in which transmitter/receiver antennas operate without beam steering, this will improve their performance hugely. Transmitter power is reduced, saving energy and reducing electromagnetic radiation, and inter-channel interference is reduced due to the space resolution of radiation directions.The main barrier preventing the development of phased-array antennas is the high cost of the antenna control systems containing banks of phase-shifters. The cost of ferrite or semiconductor based phase-shifters in these banks depends on frequency band and costs from $50 (L-band) up to $250 (Ka-band) and more for one unit. Taking into account the need to use between 20-1000 similar devices for each antenna to provide the required antenna parameters it becomes clear that 60 - 90% of the price of steerable beam antennas is connected with their control system. Phase-shifters and other control devices based on ferroelectric films can reduce the cost of a single element down to a few dollars due to their technological simplicity. However, ferroelectric devices exhibit residual polarization (a hysteresis phenomenon that is observed after decreasing the bias voltage down to zero) and slow relaxation at pulsed control voltage. This disadvantage is the main barrier for their implementation, as it causes a decrease of tunability and an ambiguous time response to the pulsed control voltage. The aim of this proposal is to develop new tuneable [ferroelectric] devices based on a new phenomenon. We and our collaborators have made an interesting observation: a reduction in the hysteresis of ferroelectric materials upon the application of ultra violet light. This discovery requires further experimentation. The effect could be used in an entirely new generation of electronic devices.

术语“光束控制”是指对光束进行聚焦，以提高到达特定目标的光量，就像探照灯一样。但为了增加覆盖范围，光束被快速调制——探照灯非常快速地来回扫过。同样的原理也适用于无线电波和微波。该提案的目的是制造一个可以电子控制的天线阵列，以提高聚焦能力。为了实现这一目标，我们需要移相器，这些设备可以在施加电压时改变输出信号相位。与当前的通信系统（其中发射器/接收器天线在没有波束控制的情况下运行）相比，这将极大地提高其性能。发射机功率降低，节省能源并减少电磁辐射，并且由于辐射方向的空间分辨率而减少通道间干扰。阻碍相控阵天线发展的主要障碍是包含组的天线控制系统的高成本移相器。这些组中基于铁氧体或半导体的移相器的成本取决于频段，一台设备的成本从 50 美元（L 波段）到 250 美元（Ka 波段）不等。考虑到每个天线需要使用 20-1000 个类似设备来提供所需的天线参数，很明显可操纵波束天线的 60-90% 价格与其控制系统相关。由于技术简单，基于铁电薄膜的移相器和其他控制装置可以将单个元件的成本降低至几美元。然而，铁电器件表现出残余极化（将偏置电压降低至零后观察到的磁滞现象）和脉冲控制电压下的缓慢弛豫。这一缺点是其实施的主要障碍，因为它导致可调谐性降低以及对脉冲控制电压的模糊时间响应。该提案的目的是开发基于新现象的新型可调谐[铁电]器件。我们和我们的合作者做了一个有趣的观察：应用紫外线后铁电材料的磁滞现象减少。这一发现需要进一步的实验。该效应可用于全新一代电子设备。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Effect of ultraviolet radiation on slow-relaxation processes in ferroelectric capacitance structures

紫外线辐射对铁电电容结构慢弛豫过程的影响

DOI：
10.1063/1.3327236
发表时间：
2010-04-20
期刊：
Journal of Applied Physics
影响因子：
3.2
作者：
P. Petrov;N. Alford;A. Kozyrev;M. Gaǐdukov;A. Altynnikov;A. Vasilevskiy;G. Konoplev;A. Tumarkin;A. Gagarin
通讯作者：
A. Gagarin

Dissociation of misfit and threading dislocations in Ba0.75Sr0.25TiO3 epitaxial film

Ba0.75Sr0.25TiO3 外延薄膜中失配和螺纹位错的解离