A novel frequency continuously tunable patch-slot antenna with wide-angle discrete scanning performance and one optional backward radiation state is presented. This antenna originates from combining one patch antenna with two endfire radiation slot antennas. By loading varactors on the patch, the working frequency is continuously adjusted, and simultaneously the maximum beam direction could be reconfigured by controlling four PIN diodes located on two slots. The proposed antenna is capable of reconfiguring its maximum beam direction to six discrete angles at 0°, −36°, −78°, +36°, +78°, and 180°. A prototype is fabricated and measured to validate the design, and experimental results demonstrate that the antenna has the merits of both wide-angle beam discrete scanning performance of ±78° in the H -plane and switchable backward radiation feature within frequency tuning range of 2.24–2.58 GHz.

中文翻译：

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具有广角离散扫描和可选向后辐射的频率连续可调贴片缝隙天线

提出了一种具有广角离散扫描性能和一种可选的向后辐射状态的新型频率连续可调贴片缝隙天线。该天线源自将一个贴片天线与两个端射辐射缝隙天线组合在一起。通过将变容二极管加载到贴片上，可以连续调节工作频率，同时可以通过控制位于两个插槽上的四个PIN二极管来重新配置最大光束方向。所提出的天线能够将其最大波束方向重新配置为0°，-36°，-78°，+ 36°，+ 78°和180°的六个离散角度。制作了原型并进行了测量以验证设计，实验结果表明，该天线在广角波束离散扫描性能方面具有±78°的优点。H 平面和可切换的向后辐射特性在2.24–2.58 GHz的频率调谐范围内。