Broadband Circularly Polarized Slot Antenna Research Articles

A Compact Broadband Circularly Polarized Slot Antenna With Two Linked Rectangular Slots and an Inverted-F Feed Line

In this communication, a broadband circularly polarized slot antenna with an inverted-F-shaped microstrip feed line and two linked rectangular slots in the ground plane is proposed. This antenna offers a wide 3 dB axial ratio (AR) bandwidth in a compact size (previously proposed slot antennas with a similar AR bandwidth are almost double in size) without employing vias or other passive components. Measured AR bandwidth is 83.5% (4.3 and 3–7.3 GHz) which is completely overlapped by the measured $S_{11}$ bandwidth of 92.6% (5 and 2.9–7.9 GHz).

Broadband Circularly Polarized Slot Antenna Loaded by a Multiple-Circular-Sector Patch.

In this paper, a microstrip-fed broadband circularly polarized (CP) slot antenna is presented. CP operation can be attained simply by embedding an S-shaped strip. By loading with a multiple-circular-sector patch, which consists of 12 circular-sector patches with identical central angles of 30° and different radii, the 3 dB axial ratio (AR) bandwidth is significantly broadened. To validate the performance of the proposed antenna, an antenna prototype is fabricated and tested. The fabricated antenna is 54 mm × 54 mm × 0.8 mm in size. The measured −10 dB reflection and 3 dB AR bandwidths are 81.06% (1.68–3.97 GHz) and 70.55% (1.89–3.95 GHz), respectively. Within the 3 dB AR bandwidth, the measured peak gain is 3.81 dBic. Reasonable agreement is also obtained between the measured and simulated results.

Broadband Circularly Polarized Slot Antenna Array Fed by Asymmetric CPW for C-Band Applications

ABSTRACTIn this manuscript, a new design of broadband circularly polarized (CP) array antenna is presented. A 2 × 2 planar array antenna is accomplished using the proposed CP diamond-shaped slot element with an L-shaped patch. The feed network employs a 180-degree rat-race hybrid coupler to realize a −3 dB power split, equal in magnitude, 180-degree difference in phase. Two branch-line couplers then divide the signal energy into two paths and give the signal to each of the output branches with the same amplitude, but phase-shifted by 90 degrees, wherein the relative phases at four feed points are 0, 90, 180, and 270 degrees. The final dimensions of the 2 × 2 element array are 112 × 97 × 0.8 mm3. The simulated result shows that the impedance bandwidth for a voltage standing wave ratio (VSWR) < 2 is around 39.86% (4.78–7.16 GHz), and the 3-dB simulated AR (axial ratio) bandwidth is about 24.2% (4.83–6.16 GHz), and the antenna has a peak gain of 7.69 dBi over the bandwidth.

A Novel Design on Broadband Circularly Polarized Slot Antenna

In this paper, a novel broadband circularly polarized (CP) slot antenna is proposed and fabricated, in which the perturbation configuration with two quarter annular rings fabricated cornerways in the square slot is designed and a simple Photonic-bandgap (PBG) structure is employed. Through simulating and testing, the broad impedance bandwidth of 81.5%(VSWR&lt;2.0) and the 3dB axial ratio (AR) bandwidth of 48.2% are achieved respectively. This slot antenna will be widely utilized in communication field. These instructions give you basic guidelines for preparing papers for conference proceedings.

Compact Broadband Circularly Polarized Slot Antenna Using Two Linked Elliptical Slots for C-Band Applications

A compact broadband circularly polarized elliptical slot antenna (CPESA) composed of two linked elliptical slots is presented. In order to realize the proposed CP antenna, two rectangular stubs are embedded in the feedline structure to excite two orthogonal E vectors. By embedding two rectangular stubs in the feedline structure and removing of four rectangular slits from the ground plane, the return loss and the axial-ratio (AR) bandwidths are noticeably increased. The designed CPESA with the compact size of 20 × 20 × 1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> operates over the frequency band between 4.3-8 GHz (60%) for and exhibits a 40% (4.3-6.5 GHz) CP bandwidth. Throughout this letter, the design process of the proposed antenna is presented and discussed in detail .

Broadband Circularly Polarized Slot Antenna Array Using Sequentially Rotated Technique for $C$-Band Applications

This letter presents the investigation results on a novel circularly polarized square-slot antenna (CPSSA) array designed to operate at a frequency of 5.5 GHz. In order to realize the proposed antenna array, four miniature circular polarized square-slot antennas are used with L-shape grounded strips located at the slots' opposite corners to reduce cross polarization. The antenna is fed by symmetric coplanar waveguide. The CPSSA element achieves a bandwidth of 16.6% for an axial ratio $\leq 3~$ dB. The CPSSA's performance is further enhanced with the construction of a novel 2 $\,\times\,$ 2 antenna array that is designed using sequentially rotated feed technique. The 3-dB axial ratio of the array extends to approximately 2 GHz with an impedance bandwidth of 31%. The CPSSA array was designed to operate over the frequency range between 4 and 6.825 GHz corresponding to an impedance bandwidth of 52% for ${\rm VSWR} (1.71:1). Acceptable agreement between the simulation and measured results validates the proposed design.

Design of a compact broadband circularly-polarized slot antenna for wireless applications

This article presents design of a compact broadband circularly-polarized square slot antenna with a coplanar waveguide feed.A circular polarization bandwidth larger than 64.7% (3172-6211 MHz) obtained with the proposed antenna by embedding two inverted-L grounded strips and a 45° bended strip around corners, whereas the impedance bandwidth can be greatly improved through the tuning stubs. 3 dB axial ratio bandwidth of the proposed CP antenna is large as 64.7% in a frequency band of 3172-6211 MHz. The CP antenna operates in a frequency range from 2.25 to 6.75 GHz and 8.25 to 10.25 GHz with VSWR < 2 impedance bandwidth. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:413-418, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27303

Broadband Circularly Polarized Slot Antenna Array Fed by Asymmetric CPW for L-Band Applications

A novel broadband circularly polarized (CP) slot antenna array fed by asymmetric coplanar waveguide (CPW) with an inverted L-shaped strip for L-band applications is proposed. Broadband CP is obtained by an array composed of elliptically polarized elements using sequential rotation feed technique. Experimental results show that the VSWR les 1.5 impedance bandwidth and the 3-dB axial ratio bandwidth can be greatly raised to be as high as 52% (1.151.95 GHz) and 49% (1.151.9 GHz), respectively. The proposed antenna can provide a peak antenna gain of about 8 dBi at 1.5 GHz, with gain variations less than 1.5 dB for frequencies within the CP bandwidth. Good agreement is observed between simulation and measurement.