Reconfigurable and Integrated Antennas for Cognitive Radio

认知无线电(CR)是一项革命性的技术，旨在显著提高频谱使用效率。认知无线电源于软件无线电的概念，可以看作是软件无线电在环境意识方面的延伸。基本上，CR依赖于无线电能够感知特定频段是否正在被使用，如果没有使用，则在不干扰其他授权用户的传输的情况下利用该频谱。如果主用户返回到同一频段进行传输，则无线电切换到另一频段，或停留在同一频段，修改其传输功率电平或调制方案以避免干扰。这种适应或改变的敏捷性允许这样的无线电感知周围的世界并从经验中学习。尽管这种网络的软件和情报要求尚未确定，但对无线电本身的影响构成了巨大的挑战。要实现频谱灵活性的这一能力，优化功率、调制、范围和其他通信参数，极其灵活的射频前端至关重要。因此，天线前端的挑战是巨大的，这在本提案中得到了解决。

Cognitive radio (CR) is a revolutionary technology that aims for remarkable improvements in efficiency of spectrum usage. Originating from the concept of software defined radio (SDR), CR can be viewed as an extension of SDR in terms of environmental awareness. Basically, CR relies on a radio being able to sense whether a particular band is being used and, if it is not, to utilise the spectrum without interfering the transmission of other authorised users. If the primary user returns to the same band for transmission, the radio switches to another band, or stays in the same band, modifying its transmission power level or modulation scheme to avoid interference. Such agility to adapt or to change allows such the radio to perceive the world around it and learn from experience. Although the software and intelligence requirements of such a network have yet to be defined, the implications on the radio itself pose tremendous challenges. To achieve this capacity for spectrum agility, optimising for power, modulation, range and other communication parameters, an extremely flexible RF front end is vital. As such, the antenna front end challenges are immense, which are addressed in this proposal.