Epsilon-shaped circularly polarized strip and slot-loaded ultra-wideband antenna for Ku-band and K-band

摘要

A compact epsilon-shaped (ε) ultra-wideband (UWB) antenna for dualwidebandcircularly polarized (CP) applications has been investigated in thisarticle. It consists of a stepped stub loaded modified annular ring-shaped radiatorand modified CPW ground plane. The ground plane is loaded with twosemicircular 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 mm~2.The fractional axial ratio bandwidth (3-dB ARBW) for two wide bands is38.50% (13.30-19.64 GHz) and 6.45% (26.25-28.00 GHz), respectively. The proposedantenna is left-hand circularly polarized with a peak gain of about 5.09and 5.14 dB in both 3-dB ARBW bands. The proposed antenna is dominatingother reported CP antenna structures in terms of number of CP bands, 3-dBARBW, IBW, peak gain, and dimensions.