A novel reconfigurable antenna covering an 11.5:1 bandwidth is designed and fabricated for cognitive radio applications. The proposed novel antenna has two independent paths to cover 430 MHz to 5 GHz frequency range. The first path is directly connected to an ultrawideband antenna, which covers 1–5 GHz operation frequency range. The second path, for the frequency range between 430 MHz and 1 GHz, goes through a dc-controlled varactor-based matching network. The switching functionality between wideband (1 to 5 GHz) and reconfigurable region (430 MHz to 1 GHz) is realized by two discrete switches. The designed antenna has a simple structure and compact size of 60 mm $\times100$ mm. The proposed novel antenna has great potential for use in cognitive radio systems.

中文翻译：

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一种用于认知无线电应用的新型紧凑型可重构宽带天线

一种覆盖 11.5:1 带宽的新型可重构天线是为认知无线电应用设计和制造的。拟议的新型天线有两个独立的路径，以覆盖 430 MHz 至 5 GHz 的频率范围。第一条路径直接连接到超宽带天线，覆盖 1-5 GHz 的工作频率范围。对于 430 MHz 和 1 GHz 之间的频率范围，第二条路径通过基于直流控制的变容二极管匹配网络。宽带（1 至 5 GHz）和可重构区域（430 MHz 至 1 GHz）之间的切换功能由两个分立开关实现。设计的天线结构简单，尺寸紧凑，60 mm $\times100 $ mm。所提出的新型天线在认知无线电系统中具有巨大的潜力。