Filtering by Aliasing: Sharp Programmable Integrated Filters using Simple Time-Varying Components

这是一个极好的建议，将对无线通信接收器做出重大贡献，并将允许增强对无线电频谱的访问。这一点变得非常关键，因为频谱接入正在成为一个重大的社会问题。这项研究如果成功，将缓解其中的一些问题，并将产生重大的社会效益。它还载有一项推广活动和研究与教育结合的综合计划。更广泛的影响项目的更广泛的影响至少有两方面。首先，研究活动带来了可重构集成滤波器设计的突破，这对软件定义无线电和认知无线电的研究，特别是通信系统的发展和电子工业的发展至关重要。特别是，在不久的将来，启用认知无线电可能会支持对更多私人和公共连接的日益增长的需求。其次，研究活动的结果和发现将有助于开发学术材料，并培训未来的电路和系统设计师，让他们了解多学科思维对解决当前和未来通信系统问题的重要性。提出的研究目标是开发锐利的、可编程的集成滤波器，使包括软件定义和认知无线电在内的广泛应用成为可能。所述滤波器将减小所接收通信信号的带宽和动态范围，使其适于数字化和随后的接收机处理。所提出的方法是采用简单但周期性时变的电路元件，在数字化之前显著提高采样实例的有效滤波。这项研究的智力价值在于，使用周期性时变元件是一种更有效的、从根本上不同的电路设计方法。今天，大多数滤波器都是时不变的，特别是在无线接收器中，它们需要高质量的声学滤波器组件，这些组件体积大，价格昂贵，难以集成，最重要的是，不可编程。拟议的方法将消除对这种不灵活的组成部分的需要。所提出的研究的具体目标是使用原型集成电路进行验证，并开发必要的理论方法来分析时变电路。预计后者也将使周期性时变电路在滤波器设计应用之外得到更广泛的接受。

THIS IS AN EXCELLENT PROPOSAL WHICH WILL MAKE SIGNIFICANT CONTRIBUTIONS TO WIRELESS COMMUNICATION RECEIVERS AND WILL ALLOW ENHANCED ACCESS TO THE RADIO SPECTRUM. THIS IS BECOMING VERY CRITICAL SINCE SPECTRUM ACCESS IS BECOMING A MAJOR SOCIETAL ISSUE. THIS RESEARCH, IF SUCCESSFUL, WILL ALLEVIATE SOME OF THESE PROBLEMS AND WILL RESULT IN MAJOR SOCIETAL BENEFITS. IT ALSO CONTAINS A COMPREHENSIVE PLAN FOR OUTREACH ACTIVITIES AND INTEGRATION OF RESEARCH AND EDUCATION.BROADER IMPACTSThe broader impacts of the project are at least two fold. First, the research activity brings a breakthrough in the design of reconfigurable integrated filters that is crucial to the re-search on software-defined and cognitive radios and the growth of communication systems in particular and the electronics industry in general. In particular, enabling cognitive radios can po-tentially support the increasing demand for more private and public connectivity in the near fu-ture. Second, the results and discoveries of the research activities will be useful in developing academic material and training future circuits and systems designers in the importance of multi-disciplinary thinking for solving current and future communication systems problems.INTELLECTUAL MERITThe objective of the proposed research is to develop sharp, programmable integrated fil-ters that will enable a wide range of applications including software defined and cognitive radios. Such filters will reduce the bandwidth and the dynamic range of the received communication signals rendering them amenable to digitization and subsequent receiver processing. The proposed approach is to employ simple but periodically time-varying circuit components to significantly enhance effective filtering at sampling instances prior to digitization. The intellectual merit of the research is that the use of periodically time-varying components is a much more efficient and fundamentally different approach to circuit design. Today, most filters are of the time-invariant variety and particularly in the wireless receiver, they need high quality acoustic filter components that are bulky, expensive, difficult to integrate and most importantly, not programmable. The proposed approach will obviate the need for such inflexible components. Specific goals of the proposed research are validation using a prototype integrated circuit and the development of necessary theoretical methods to analyze time-varying circuits. It is expected that the latter will also enable wider acceptance of periodically time varying circuits beyond filter design applications.