A compact epsilon‐shaped (ε) ultra‐wideband (UWB) antenna for dual‐wideband circularly polarized (CP) applications has been investigated in this article. It consists of a stepped stub loaded modified annular ring‐shaped radiator and modified CPW ground plane. The ground plane is loaded with two semicircular notches and a spiral‐shaped slot. The impedance bandwidth (IBW) is 97.02% (10.4‐30 GHz) along with an overall footprint of 20 × 20 mm². The fractional axial ratio bandwidth (3‐dB ARBW) for two wide bands is 38.50% (13.30‐19.64 GHz) and 6.45% (26.25‐28.00 GHz), respectively. The proposed antenna is left‐hand circularly polarized with a peak gain of about 5.09 and 5.14 dB in both 3‐dB ARBW bands. The proposed antenna is dominating other reported CP antenna structures in terms of number of CP bands, 3‐dB ARBW, IBW, peak gain, and dimensions.

中文翻译：

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用于Ku波段和K波段的Epsilon形圆极化带状和缝隙式超宽带天线

本文研究了一种用于双宽带圆极化（CP）应用的紧凑型ε形（ε）超宽带（UWB）天线。它由阶梯状的短管加载的改进的环形环状散热器和改进的CPW接地平面组成。接地平面上装有两个半圆形槽口和一个螺旋形槽。阻抗带宽（IBW）为97.02％（10.4-30 GHz），总占地面积为20×20 mm ²。两个宽带的轴向比例分数带宽（3-dB ARBW）分别为38.50％（13.30-19.64 GHz）和6.45％（26.25-28.00 GHz）。拟议中的天线是左旋圆极化的，在两个3 dB ARBW频带中的峰值增益分别约为5.09和5.14 dB。就CP频段的数量，3-dB ARBW，IBW，峰值增益和尺寸而言，拟议的天线将主导其他报告的CP天线结构。