scholarly journals Bandwidth-Enhanced Circularly Polarized Crescent-Shaped Slot Antenna via Circular-Patch Loading

2019 ◽  
Vol 9 (6) ◽  
pp. 1117 ◽  
Author(s):  
Son Trinh-Van ◽  
Youngoo Yang ◽  
Kang-Yoon Lee ◽  
Yong Kim ◽  
Keum Hwang

This paper presents the crescent-shaped slot antenna loading of a circular patch that greatly enhances a 3 dB axial-ratio (AR) bandwidth. A bent feeding line was introduced and attached to a 50- Ω microstrip feed line to achieve circular polarization operation. By loading the circular patch into a crescent-shaped slot at a proper position, the 3 dB AR bandwidth is considerably broadened. An antenna prototype with overall dimensions of 50.8 × 50.8 × 0.5 mm 3 is experimentally demonstrated. Measurement results of the fabricated antenna showed a wide −10 dB reflection bandwidth of 92.33% (1.79–4.86 GHz) and a broad 3 dB AR bandwidth of 84.40% (1.89–4.65 GHz). The measured peak gain of the antenna was approximately 4.09 dBic at 2.9 GHz. Good agreement was also achieved between measurement and simulation results.

Author(s):  
Chandravilash Rai ◽  
Sanjai Singh ◽  
Ashutosh Kumar Singh ◽  
Ramesh Kumar Verma

Abstract A circularly polarized ring cylindrical dielectric resonator antenna (ring-CDRA) of wideband impedance bandwidth is presented in this article. The proposed ring CDRA consist of an inverted rectangular (tilted rectangular) shaped aperture and inverted L-shaped slotted microstrip feed line. The tilted rectangular shaped aperture and inverted L-shaped microstrip feed line generate two-hybrid mode HEM11δ and HEM12δ while ring CDRA and slotted microstrip feed line are used for the enhancement of impedance bandwidth. The proposed ring CDRA is resonating between 6.08 and 12.2 GHz with 66.95% (6120 MHz) impedance bandwidth. The axial ratio (AR) bandwidth of 6.99% (780 MHz) is obtained between 10.76 and 11.54 GHz with a minimum AR value of 0.2 dB at a frequency of 11 GHz. The proposed geometry of ring CDRA has been validated with measurement performed by VNA and anechoic chamber. The operating range of the proposed radiator is useful for different applications in X-band.


2019 ◽  
Vol 11 (10) ◽  
pp. 1054-1060
Author(s):  
Kapil Saraswat ◽  
A. R. Harish

AbstractA polarization and band reconfigurable cross-slot antenna for multiband applications is presented in this paper. The antenna consists of four p–i–n diodes embedded in the cross-shaped slot in a ground plane and excited by a microstrip feed line. The p–i–n diodes are placed in such a way that they produce multiple bands, with linearly and circularly polarized (CP) radiation. By switching the states of the p–i–n diodes, the sense of rotation of the electric field in CP radiation can be reconfigured. The proposed structure can be configured to produce two bands that radiate linearly polarized waves or three bands, where, two are linearly polarized and one is CP. The proposed design concepts are validated bythe CST studio suite as well as measurementsare carried out on fabricated prototypes.


2019 ◽  
Vol 11 (9) ◽  
pp. 872-884 ◽  
Author(s):  
Sherif R. Zahran ◽  
Mahmoud A. Abdalla ◽  
Abdelhamid Gaafar

AbstractIn this paper, a flexible single fed planar circular polarized slot antenna is proposed for Internet of Things wideband applications. The antenna flexibility is achieved by employing a mechanically bendable liquid crystalline polymer substrate. The overall antenna volume is 50 mm × 42 mm × 0.1 mm. The antenna design uses 45° rotated elliptical ground structure for generating circular polarized radiation over wideband spectrum. Two parametrical analyses targeting the slot ground are introduced in order to achieve the most efficient design. The final antenna design demonstrates a good matching in terms of reflection coefficient (<−10 dB), semi-omnidirectional radiation patterns, average gain of 4 dB, and <3 dB axial ratio over entire frequency band of operation. All antenna parameters are studied in both straight and bent antenna setup scenarios. Good agreement between simulation and measurement results of the antenna parameters are achieved. For both straight and bent antenna scenarios, the antenna receiving functionality in time domain is confirmed by retrieving highly correlated impulse responses.


2016 ◽  
Vol 9 (3) ◽  
pp. 649-656 ◽  
Author(s):  
Neng-Wu Liu ◽  
Lei Zhu ◽  
Wai-Wa Choi

A low-profile circularly polarized (CP) slot antenna to achieve a wide axial-ratio (AR) beamwidth is proposed in this paper. The radiating patch consists of two orthogonal pairs of parallel slots etched symmetrically onto a ground plane. Firstly, our theoretical study demonstrates that the CP radiation can be satisfactorily achieved at the broadside, when the vertical and horizontal paired-slots are excited in the same amplitude with 90° phase difference. Secondly, the principle of CP radiation of the proposed antenna on an infinite ground plane is described. Through analyzing the spacing between two parallel slots, the |Eθ| and |Eφ| radiation patterns can be made approximately identical with each other over a large angle range. As such, the slot antenna achieves a wide AR beamwidth. After that, the 3 dB AR beamwidth with respect to the size of a finite ground plane is investigated to constitute a practical CP antenna on a finite ground plane. In final, the proposed CP antenna with a 1–4 probe-to-microstrip feeding network is designed and fabricated on a finite ground plane of a dielectric substrate. Measured results are shown to be in good agreement with the simulated ones about the gain, reflection coefficient, AR bandwidth, and radiation patterns. Most importantly, a wide 3 dB AR beamwidth of 126° and low-profile property with the height of 0.036λ0 are achieved.


2015 ◽  
Vol 8 (8) ◽  
pp. 1237-1242 ◽  
Author(s):  
Neha Sharma ◽  
Anil Kumar Gautam ◽  
Binod Kumar Kanaujia

In this paper, a novel circularly polarized square slot microstrip antenna is proposed for radio frequency identification (RFID) applications. The circular polarization is achieved by incorporating an arc-shaped strip in the square slot antenna. This antenna is fed by deformed bent feeding line to achieve a broad bandwidth (BW). The key parameters of the antenna are used for parametric study to understand the influence on the antenna performance. To validate simulation results of the design, a prototype is fabricated on the commercially available FR4 material. Measured results show a good agreement with the simulated results. It is found that the antenna shows an impedance BW of 170 MHz (844–1014 MHz) and axial-ratio BW of 170 MHz (834–1004 MHz), which shows that the proposed antenna is a good candidate to be used as a RFID antenna.


2019 ◽  
Vol 12 (3) ◽  
pp. 212-220 ◽  
Author(s):  
Alka Verma ◽  
Anil Kumar Singh ◽  
Neelam Srivastava ◽  
Shilpee Patil ◽  
Binod Kumar Kanaujia

AbstractIn this paper, an electromagnetic band gap (EBG) metasurface (MS) superstrate-based circularly polarized antenna for the WiMAX (3.5 GHz) band is proposed. The proposed structure comprises a 2 × 2 slot-loaded rectangular patch MS array that can be perceived as a polarization-dependent EBG MS superstrate. Furthermore, to achieve circular polarization, the proposed antenna has an inclined coupling slot onto the ground with a conventional coplanar waveguide feed line. The proposed antenna has a compact structure with a low profile of 0.037λ0 (λ0 stands for the free-space wavelength at 3.48 GHz) and a ground size of 30 × 30 mm2. The measured results show that the −10 dB impedance bandwidth for the proposed antenna is 34.6% and the 3-dB axial ratio (AR) bandwidth is 6.8% with a peak gain of 3.91 dBi in the desired operating band. Good agreement between the simulated and the measured results verifies the performance of the proposed antenna.


2020 ◽  
Vol 9 (1) ◽  
pp. 41-48
Author(s):  
P. M. Paul ◽  
K. Kandasamy ◽  
M. S. Sharawi

A compact multiband circularly polarized slot antenna is proposed here. An F-shaped microstrip feedline is used to excite the square slot antenna loaded with a U-shaped strip and a split ring resonator (SRR) to generate three circularly polarized bands at 1.5 GHz, 2.75 GHz and 3.16 GHz. A meandered slot is used in the feedline and the U-strip to improve the axial ratio bandwidth (ARBW). The meandered feedline excites the slot to produce resonance at 2.5 GHz. This resonance along with that of the F-shaped feed, loaded SRR and U-strip combine to give rise to three circularly polarized bands which can be tuned depending on the feed, SRR and U-strip dimensions. The orientation of the F-shaped feed decides the sense of polarization of the three circularly polarized bands of the proposed antenna. The proposed antenna is fabricated on a substrate of FR4 material with dimensions 50 x 50 x 1.56 mm3. The antenna is prototyped and measured in terms of impedance bandwidth, ARBW, gain and efficiency. The simulated and measured results show reasonably good agreement.


Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shilpee Patil ◽  
Anil Kumar Singh ◽  
Vijay Kumar Pandey ◽  
Binod Kumar Kanaujia ◽  
Anil Kumar Pandey

Abstract A simple and compact circularly polarized broadband circular slot antenna is proposed for WLAN/WiMAX/DBS applications. The main objective of this work is to design a microstrip line fed broadband circularly polarized antenna that is achieved by introducing an asymmetric perturbation over the circular slot onto the ground plane. A broad axial ratio bandwidth is achieved by using a small circular segment cut into the circular slotted ground and by adding a short stub on the feedline. To achieve a broad impedance bandwidth, a horizontal strip onto the slotted ground is placed just above the feed line on the opposite side. The proposed antenna is fabricated with an overall dimension of 20 × 20 × 1.6 mm3 (0.34λ o × 0.34λ o × 0.03λ o, where λ o represents the free-space wavelength at the center operating frequency). It is found that the impedance bandwidth of 75.82% ranges from 3.21 to 7.13 GHz and the 3 dB axial ratio (AR) bandwidth reaches 54.27% from 3.8 to 6.6 GHz. Throughout this paper, the improvement and validation process of the proposed antenna outcomes to accomplish desired characteristics are discussed.


2018 ◽  
Vol 11 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Shilpee Patil ◽  
A. K. Singh ◽  
Binod K. Kanaujia ◽  
R. L. Yadava

AbstractA simple design for triple-band circularly polarized (CP) wide slot antennas is proposed and experimentally investigated. The proposed antenna having a microstrip-fed rectangular patch with T-shaped notch for triple-band operation and a modified wide square slot on ground plane for CP operation. The measured 10 dB reflection bandwidths are 1.24% (≈340 MHz from 2.56 to 2.9 GHz), 9.63% (≈430 MHz from 4.25 to 4.68 GHz), and 5.34% (≈490 MHz from 8.93 to 9.42 GHz). The generated 3 dB axial ratio bandwidths of the proposed antenna are 7.54, 8.98, and 1.65% at operating frequencies around 2.65, 4.45, and 9.09 GHz, respectively. The measured peak gains within the 3 dB axial ratio bands are 3.03, 3.5, and 5.64 dBi. The simulated and measured results for the return loss, axial ratio, and antenna gain show a good agreement, which validate the antenna design.


Frequenz ◽  
2019 ◽  
Vol 73 (9-10) ◽  
pp. 317-320
Author(s):  
Saeid Karamzadeh ◽  
Vahid Rafiei ◽  
Hasan Saygin

Abstract In this work circularly polarization diversity has been achieved by utilizing two Schottky diodes on low profile cavity-backed substrate integrated waveguide (CBSIW). In comparison with other studies in the literature, the size of antenna has been reduced to 0.54λg × 0.76λg by helping a 50-Ohm coaxial feed line. The impedance bandwidth, axial ratio bandwidth and antenna gain are improved to 10.02 %, 5.2 % and 7.68dBi, respectively. In addition, the proposed antenna can generate either a left-hand circularly polarized (LHCP) or a right-hand circularly polarized (RHCP) radiation. The developed antenna was fabricated and tested and the achieved results were in good agreement with the simulated one.


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