Frequency Selective Surfaces for Long Wavelengths

长波长的频率选择表面

• 批准号: EP/E021409/1
• 负责人: Anthony Brown
• 金额: $ 32.88万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE021409%2F1
• 关键词: Frequency; Selective; Surfaces; Long; Wavelengths

Mobile communications and wireless computer networking are already enourmously popular with user numbers and system types set to continue increasing. Each system requires the use of certain transmission frequencies which must be separated in some way to avoid interference. OFCOM, the government body that licences the radio spectrum is beginning to deregulate the process of radio frequency usage and it is vital to devise a means of making the radio environment both more immune from interference and safe from eavesdropping. Also prisoners who should not be allowed access to telephones are using mobile phones smuggled into prisons. The phones are used to organise crime outside, smuggle in drugs and coordinate escapes and riots. This is of great concern to the prison authorities and the UK government as it is technically difficult to stop mobile phone communications without interfering with the phones of innocent users near the prisons. Parallel to the above issues is the fact that modern buildings are lined with a metallic layer for thermal insulation. This layer screens building interiors and can significantly reduce the strength of radio signals passing inside. This can reduce the coverage of radio systems used by the emergency services within buildings placing personnel at risk. This research seeks to create Frequency Selective Surfaces (FSS) to filter out radio signals at mobile frequencies while passing channels used by authorised services. The FSS designs will be convoluted and interweaved to compress their size and will be mounted in small apertures in metal screened walls. A specified isolation level will be aimed for and the performance will be made adaptable by integrating switching diodes to the design. Computer simulations will be made to predict the propagation of signals through the FSS and into rooms.

移动的通信和无线计算机联网已经非常流行，用户数量和系统类型将继续增加。每个系统都需要使用某些传输频率，这些频率必须以某种方式分开以避免干扰。OFCOM是授权无线电频谱的政府机构，它开始放松对无线电频率使用过程的管制，设计一种使无线电环境更不受干扰和窃听的方法至关重要。此外，不应允许使用电话的囚犯正在使用偷运进监狱的移动的电话。这些手机被用来组织外部犯罪、走私毒品以及协调越狱和骚乱。这是监狱当局和英国政府非常关注的问题，因为在技术上很难在不干扰监狱附近无辜用户电话的情况下阻止移动的电话通信。与上述问题平行的是，现代建筑物内衬有金属层用于隔热。这一层屏蔽了建筑物内部，可以显著降低通过内部的无线电信号的强度。这可能会减少建筑物内紧急服务所使用的无线电系统的覆盖范围，使人员处于危险之中。这项研究旨在创建频率选择表面（FSS），以过滤出移动的频率的无线电信号，同时通过授权服务使用的信道。FSS的设计将是回旋和交织，以压缩其大小，并将安装在金属屏蔽墙的小孔。一个指定的隔离水平将是目标和性能将通过集成开关二极管的设计适应。将进行计算机模拟以预测信号通过FSS并进入房间的传播。

项目成果

Simulation of Propagation through a Frequency Selective Wall at 3GHz

3GHz 频率选择性墙传播仿真

• 发表时间: 2010
• 作者: M Yang