In this paper, a microstrip‐fed narrow slot antenna with end‐fire radiation and expanded bandwidth under dual‐resonant modes operation is proposed. At first, the open‐ended slot radiator is studied and used to effectively suppress all the undesired even‐order modes, reduce the antenna size, and form up the end‐fire radiation pattern simultaneously. After that, by symmetrically introducing a pair of slot stubs near the electric‐field distributions nodal lines of its second odd‐order mode, the resonant frequency of second odd‐order mode is gradually moved down. As such, the first and second odd modes could be effectively moved in proximity to each other, thus resulting in the improved impedance bandwidth of the slot antenna under dual‐mode operation. To validate the predicted results, the proposed wideband microstrip‐fed slot antenna is in final fabricated and measured. Both simulated and measured results are derived with good agreement. Measured results indicate that the impedance bandwidth of the slot antenna has achieved an immense enhancement up to about 25.5% (2.43‐3.14 GHz). Moreover, the front‐to‐back ratio (FBR) beyond 6.0 dB has been successfully obtained across the whole operating band for end‐fire radiation.

中文翻译：

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在双共振模式下具有端射辐射的宽带微带馈送缝隙天线

本文提出了一种在双共振模式下具有端射辐射和扩展带宽的微带馈送窄缝天线。首先，研究了开放式缝隙辐射器，并将其用于有效抑制所有不希望的偶数阶模，减小天线尺寸并同时形成端射辐射图。此后，通过在第二奇数阶模式的电场分布节点线附近对称引入一对狭缝，第二奇数阶模式的谐振频率逐渐降低。这样，第一和第二奇数模式可以有效地彼此靠近移动，从而在双模式操作下提高了缝隙天线的阻抗带宽。为了验证预测结果，拟议中的宽带微带馈送缝隙天线已完成制造和测量。模拟和测量结果均具有良好的一致性。测量结果表明，缝隙天线的阻抗带宽最大提高了约25.5％（2.43-3.14 GHz）。此外，已经成功地在整个操作频带上获得了超过6.0 dB的前后比（FBR），用于端火辐射。