Broadband Circularly Polarized Stair-Shaped Slot Antenna

Abstract

This article is introducing a novel broadband circularly polarized slot antenna fed by a coplanar waveguide, with simple layer geometry. A simple design procedure, made of seven stages, is extended to achieve the required performances. The antenna consists of two linked rectangular slots and two asymmetrical L-shaped slots embedded in opposite corners of stair-shaped ground plane with two conducting rectangles that are added to the ground plane in conjunction with a U-shaped strip. This strip is protruded into the slot from the signal line of the coplanar waveguide. By using the U-shaped patch and two conducting rectangles, two orthogonal electric fields with quadrature phase difference, it is possible to excite a circularly polarized wave. The proposed antenna, with a size of 45 × 45 × 0.8 mm 3 is enabled to operate across 1.9 to 4.5 GHz with a fractional impedance bandwidth of 81.25%; for S 11 less than -10 dB. The 3-dB axial ratio bandwidth is enclosed by the voltage standing wave ratio ≤ 2 impedance bandwidth, and can be up to 48.2% (2.33 to 3.81 GHz), which is appropriate for wireless local area network (2.4 to 2.484 GHz), digital multimedia broadcasting (2.605 to 2.655 GHz), and worldwide interoperability for microwave access (3.3 to 3.8 GHz) systems. The proposed design has been investigated by the simulated and measured results.

Gain Enhancement of Wideband Circularly Polarized UWB Antenna Using FSS

“…Circularly polarized (CP) antennas have attracted significant research interest over the last decade in wireless communication systems. These types of antennas are more flexible in terms of antennas orientation when they are used as a transmitter and receiver, and they are good candidates for reducing polarization mismatch, due to misalignment between transmitting and receiving antennas (Shirazi & Honarvar, 2015; Zarbakhsh et al, 2018; Zhang et al, 2019). Circularly polarized techniques and ultrawide bandwidth (UWB) technology are among the approaches proposed to optimize the performance of communication systems (Malekpour et al, 2017; Zhang et al, 2018).…”

“…Among them, single‐fed CP antennas are commonly used for their simple structure and ease of manufacturing. Most of these antennas use the coplanar waveguide (CPW) feed (Karamzadeh et al, 2015; Shirazi & Honarvar, 2015), and others use the probe feeding technique (Ding et al, 2017; Li et al, 2013), where the CPW‐fed structures are preferred because of their large bandwidth and low profile (Rezaeieh et al, 2013). Printed antennas have low gain, narrow CP bandwidth, which limits their applications.…”