Planar microstrip‐fed broadband circularly polarized antenna for UWB applications

Abstract

A microstrip‐fed UWB slot antenna with wide axial ratio is presented in this letter. The proposed antenna design comprises of an asymmetrical slot excited by an asymmetrical feed. The introduced asymmetrical nature alters the magnitude and phase of orthogonal E‐field components of the resonant modes generated. The asymmetry across the slot arms improves the axial ratio bandwidth (ARBW). The mechanism of obtaining circular polarization is discussed in detail and the steps taken for the improvement of ARBW is presented. The measured results of the proposed antenna have a wide impedance bandwidth (S11 < −10 dB) from 2.5 GHz to 12 GHz with ARBW of 81.1% (3.2 GHZ to 7.6 GHz). The antenna possesses the features like compact size (40 mm × 40 mm × 1.58 mm), low cost (FR4 substrate, ɛr = 4.4, tan δ = 0.02) and have easy integrability. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1088–1093, 2016

A broadband circularly polarized slot antenna with a compact microstrip to CPW transition

“…Among them, circularly polarized slot antennas are promising candidates due to the advantages of low profile, lightweight, low cost, and ease of fabrication but their bandwidth is not wide enough. Some improvements have been made to the slot antennas, such as using slot antennas with embedded slot asymmetry and feed asymmetry for ARBW. But the asymmetric structure is not easy to simulate and fabricate.…”

A CPW-fed circular patch antenna inspired by reduced ground plane and CSRR slot for UWB applications with notch band

“…The modification in ground plane by triangular truncation leads to additional resonance . The bandwidth of an antenna can be increased by introducing slot, metamaterial, defected ground plane, etc., . In the same way, the ultra‐wideband antenna can be realized using slot, fractal or metamaterial.…”

“…In the same way, the ultra‐wideband antenna can be realized using slot, fractal or metamaterial. Different configurations of UWB antennas have been reported . The antenna operates in full/part of UWB band without having notch band at WLAN 5 to 6 GHz frequencies .…”

“…Different configurations of UWB antennas have been reported . The antenna operates in full/part of UWB band without having notch band at WLAN 5 to 6 GHz frequencies . Antenna designed with notch frequency but size of those antennas are comparatively larger.…”

“…Antenna designed with notch frequency but size of those antennas are comparatively larger. Antenna designed on two‐sided copper clad FR4 substrate may add up to complexity while fabrication. The CPW fed antenna with truncated ground plane and microstrip fed antenna with reduced or truncated ground plane have been proposed for performance enhancement.…”