Wideband circularly polarized square slot antenna with an annular patch

Abstract

This article presents a novel and compact circularly polarized square slot antenna (CPSSA) that operates across 2.93–11.43 GHz with an impedance bandwidth of 118% for VSWR ≤ 2. This makes the antenna feasible for UWB applications requiring high data rate transmission. The antenna with an annular radiation patch is fed through a coplanar waveguide and includes two inverted‐L shaped ground arms at two opposite corners of the slot to excite two orthogonal resonant modes for circular‐polarization (CP) radiation. A semicircular stub is embedded in the feed‐line to enhance its impedance bandwidth. The antenna exhibits CP bandwidth of 22.2% across 4.87–6.09 GHz, which incorporates the WLAN band. In addition, the antenna has a significantly smaller volume of 25 × 25 × 0.8 mm3. The measured and simulated results confirm the usefulness of the antenna for practical applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:229–233, 2014

A novel wideband circularly polarized modified square‐slot antenna with loaded strips

“…The corresponding IBW plots and ARBW plots of the prototypes are displayed in Figure A and B, respectively. As shown in Figures and , at first, Ant I with only a square‐slot configuration that was widely used in References is poor in the AR band. When two triangle patches were added in Ant II, the AR resonant points shift toward higher frequencies, but the S11 performance hardly changes.…”

“…Nowadays, various shapes of broadband CP slot antennas have been designed to stimulate wideband CP modes. The square slot antennas with modified ground plane or parasitic elements are used to obtain broad CP bandwidths . Some strips and slots are introduced into square‐slot ground including the following: embedding a spiral slot, protruding a pair of grounded strips, and introducing two inverted‐L grounded strips, the wideband axial‐ratio bandwidths (ARBWs) of 56%, 30%, and 25% can be obtained, respectively, and also utilizing the arc‐shaped strip and embedding a lightning‐shaped feed line for broadband CP radiation .…”

“…It is noticed that parasitic elements are also often adopted to design of wideband CP antenna. A parasitic square patch, a parasitic annular patch, and two parasitic square rings are loaded into square‐slot antennas, respectively, to enhance the CP bandwidth. In addition, a broadband circularly polarized square‐slot antenna with low axial ratios in Reference .…”

Broadband Circularly Polarized Stair-Shaped Slot Antenna

“…For having an utilizable CP antenna with wide bandwidth, a simple structure, and compact size, planar configurations are critical characteristics. Some of these methods can widen the bandwidth but are complicated in practical works (Kumar & Sinha, 2009) Shirzad et al (2014), and Row and Lin (2014) have achieved CP property but have narrow axial ratio (AR) bandwidth that range from 4 to 27%. In addition, the proposed CP antennas are specified by a large size (Kumar & Sinha, 2009;Kalhor et al, 2012;Chen et al, 2012;Pan et al, 2012), or non-planar configuration (Kumar & Sinha, 2009;Pan et al, 2012).…”

“…On the other hand, it is feasible to generate a single-layer CP slot antenna by adjusting the geometrical topology of the slot configuration or the feeding line. Some of the prevalent reported methods use the following: an embedded inverted-L ground strips with an annular patch (Shirzad et al, 2014), an asymmetric T-shaped strip (Pan et al, 2012), a trapezoidal patch (Kalhor et al, 2012), an L-shaped strip with a cross-shaped ring-slot (Kumar & Sinha, 2009), a C-strip metal within the circular slot (Chen et al, 2012), a square ring-slot with an L-shaped strip (Row & Lin, 2014), and an open slot (Jan et al, 2013). For having an utilizable CP antenna with wide bandwidth, a simple structure, and compact size, planar configurations are critical characteristics.…”