This paper reports on the design and practical validation of monopole antenna arrays with reduced half-power beamwidth (HPBW) variation in a bandwidth (BW) greater than one octave of the RF spectrum. The HPBW variation is reduced by feeding the antenna elements with frequency-dependent feed networks. The feed networks are designed in such a way that the element power is gradually shifted from the outer elements at low frequencies to the inner elements at high frequencies. The operating principles of the proposed concept are explored through simulated examples of four-element arrays made of isotropic elements and then realistic monopole elements. Scalability of the concept to eight-element arrays is also explored using ideal simulations. For practical validation purposes, a four-element monopole antenna array and its corresponding feed network are designed and measured. The prototype resulted in a HPBW variation of 78% in a 2.6:1 BW, which is significantly reduced compared to the uniformly fed array, having a 216% variation.

中文翻译：

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具有减少的半功率波束宽度变化的宽带单极子阵列


本文报告了单极天线阵列的设计和实际验证，该天线阵列的半功率波束宽度 (HPBW) 变化减小，带宽 (BW) 大于射频频谱的一个倍频程。通过使用频率相关的馈电网络向天线元件馈电，可以减少 HPBW 的变化。馈电网络的设计方式使得元件功率逐渐从低频的外部元件转移到高频的内部元件。通过由各向同性元件和实际单极元件组成的四元件阵列的模拟示例，探索了所提出概念的工作原理。还使用理想模拟探索了该概念到八元素阵列的可扩展性。出于实际验证的目的，设计并测量了四元件单极天线阵列及其相应的馈电网络。该原型在 2.6:1 BW 中产生了 78% 的 HPBW 变化，与具有 216% 变化的均匀馈电阵列相比显着减小。