Frequency Agility in Microwave Dielectric Resonators

微波介质谐振器的频率捷变

• 批准号: EP/C528573/2
• 负责人: Neil Alford
• 金额: --
• 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: 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%2FC528573%2F2
• 关键词: Frequency; Agility; Microwave; Dielectric; Resonators

At present. cellular mobile communication systems use input and output filters which are tuned to cover the whole band of interest. This is done because tuneable filters that have low enough loss or do not themselves produce significant unwanted signals do not exist. For example, filters can be tuned by using varactor diodes but these are nonlinear devices which produce unwanted signals that are too large for the filters to be used in commercial communication systems. They also have low unloaded 0 which result in filters with a high insertion loss. A low loss, low spurious interference, filter which could be tuned to a single communications channel would offer tremendous advantages in the design of the rest of the system. These are:The ability to exclude, at an earlier stage in the receiver to that currently possible, signals in the same band as your own. This would considerably ease the problems of spectrum planning and greatly improve spectrum efficiency and the information transfer capacity available to users (the public). Spectrum is. of course, a unique, limited resource, so any spectrum efficiency improvements are worthwhile.The ability to reduce greatly the amount of unwanted signals radiated from a transmitter. The design of power amplifiers for 3G communication systems is much more difficult than for GSM systems. For example, the amplifiers must have a linear transfer characteristic. which is not required for GSM.In order to achieve this frequency agility we intend examining two methods. These are1 Ferroelectric/paraelectric tuning - where a voltage will alter the relative permittivity of the material and hence the frequency.2 Piezoelectric tuning - where a change in the position of a tuning element will alter the frequency.In order to verify these ideas, a prototype device of each will be manufactured and tested.The prototype will comprise* a single resonator dual mode 2 pole filter* a a 2 resonator 2 pole filter and a 2 resonator dual mode 4 pole filter

现在。蜂窝移动通信系统使用输入和输出滤波器，这些滤波器经过调谐以覆盖整个感兴趣的频段。这样做是因为不存在具有足够低损耗或本身不会产生显着不需要的信号的可调谐滤波器。例如，可以使用变容二极管来调谐滤波器，但这些是非线性器件，会产生对于商业通信系统中的滤波器来说太大的不需要的信号。它们还具有低空载 0，这导致滤波器具有高插入损耗。可以调谐到单个通信通道的低损耗、低寄生干扰滤波器将为系统其余部分的设计提供巨大的优势。它们是： 在接收器中较早阶段排除当前可能的、与您自己的频带相同的信号的能力。这将大大缓解频谱规划的问题，并大大提高频谱效率和用户（公众）可用的信息传输能力。频谱是。当然，这是一种独特的、有限的资源，因此任何频谱效率的改进都是值得的。能够大大减少从发射机辐射的不需要的信号量。 3G通信系统的功率放大器的设计比GSM系统的功率放大器的设计困难得多。例如，放大器必须具有线性传输特性。这对于 GSM 来说不是必需的。为了实现这种频率捷变，我们打算研究两种方法。这些是 1 铁电/顺电调谐 - 电压将改变材料的相对介电常数，从而改变频率。2 压电调谐 - 调谐元件位置的变化将改变频率。为了验证这些想法，将制造和测试每个设备的原型设备。原型将包括* 一个单谐振器双模 2 极滤波器* 一个 2 谐振器 2 极滤波器和一个 2谐振器双模4极滤波器