一種寬帶單脊波導縫隙天線的設計與仿真

摘 要：基于一維相掃的寬帶寬掃描角相控陣天線的需求，設計一種工作于Ku波段的單脊波導寬邊縱縫天線，使用三維電磁仿真軟件HFSS進行結構優化，得到天線具體參數。為增大帶寬將縫隙劃分為多個子陣，采用多層相同尺寸的脊波導垂直互聯，并用E-T波導功分器為每個子陣分區饋電，從而實現特定能量比的饋入。該文設計的單脊波導寬邊尺寸是同頻段標準矩形波導寬邊尺寸的73%，通過電磁仿真驗證設計方法的可行性，天線在14.6～16.4 GHz頻率范圍內達到1.8 GHz的帶寬，相對帶寬為11.6%，VSWR<1.7，副瓣電平小于-20 dB，增益大于15 dB。

關鍵詞：Ku波段;單脊波導;縫隙天線;寬帶;子陣劃分

中圖分類號：TN823 文獻標志碼：A 文章編號：2095-2945（2024）27-0139-04

Abstract： A single ridge waveguide wide edge longitudinal slot antenna operating in the Ku band was designed based on the requirements of a one-dimensional phase scanning broadband wide-angle phased array antenna. The structure was optimized using the three-dimensional electromagnetic simulation software HFSS to obtain the specific parameters of the antenna. In order to increase bandwidth， the gaps are divided into multiple sub arrays， and multi-layer ridge waveguides of the same size are vertically interconnected. E-T waveguide power dividers are used to feed each sub array partition， thereby achieving specific energy ratio feeding. The wide edge size of the single ridge waveguide designed in this article is 73% of the standard rectangular waveguide wide edge size in the same frequency band. The feasibility of the design method was verified through electromagnetic simulation. The antenna achieves the bandwidth of 1.8 GHz in the 14.6～16.4 GHz frequency range， the relative bandwidth is 11.6%， the sidelobe level is less than -20 dB， and the gain is greater than 15 dB.

Keywords： Ku band; single ridged waveguide; slot antenna; broadband; subarray division

波導縫隙天線因其損耗低、口徑分布容易控制、易于實現低副瓣、功率容量高、機械強度好和可靠性高等優點[1]，被廣泛應用在雷達和通信領域，成為一維相掃的相控陣天線的優選方案之一。傳統的諧振式波導縫隙天線其工作頻帶受到縫隙數目的限制，通?？p隙數目越多則帶寬越窄[2]，這也嚴重影響了雷達的工作性能。因此，需要對增大波導縫隙天線的工作帶寬進行設計。

單脊波導示意圖如圖1所示，通過在波導寬邊加一定寬度和高度的金屬脊，使其不僅具有了矩形波導縫隙天線的一系列優點，而且在同一頻率下，單脊波導的寬邊尺寸更小，對于相控陣天線的寬角掃描很有益處。在同樣頻帶的情況下，脊波導橫截面的尺寸一般可以減小到矩形波導的70%左右[3]。……